BATC Wiki - User contributions [en-gb]

Gerber Files

2026-03-27T21:12:26Z

M0YDH:

This is a centralised index of Gerber Files which have been used for BATC and BATC Members' projects.

No responsibility is accepted for any errors, but they are listed here to promote home construction and experimentation.

Files should be uploaded as .zip files, and should also be referenced from another Wiki page describing the project.

===Ryde Front Panel===

The Ryde Front Panel Push Button PCB as descried here: [[Ryde_Hardware#Ryde_front_panel]]

[[File:Gerbers.zip|thumb|Ryde Front Panel PCBGerbers]]

===ADF4351 PIC Controller===

The ADF4351 PIC Controller described here: [[ADF435x_PIC]]

[[:File:adf435x.zip]]

===DATV Repeater Audio Switch===

The DATV Repeater Audio Switch as described here [[DATV_repeater_audio_switch]]

[[:File:REPEATER I2C AUDIO SWITCH V2022.zip]]

===G0MJW's Ryde board===

This is like a plug in board for the PI4 that provides the 5V PSU, a cooling option and Ryde IO interface. The information is all below. There are two PSU options, only one is required. All fairly simple. These Gerbers are set up for JLC PCB. In theory all you need to do is upload the zip file with the gerbers and select quantity, solder mask colour and postage options. The BOM is an HTML file in the ibom zip.

[[:File:RydeGpioV2.zip]]

[[File:RYDE GPIO 3D.jpg|500px]]

[[File:RydeV2Schematic.jpg|500px]]

[[:File:ibom.zip]]

===G0MJW's PD4 board===

TBC (after CAT22)

This is a PCB to implement a Portsdown 4 with 25 pid connector for interfacing to test equipment and a PTT transistor that can switch light loads. There are also headers for the Langstone.

[[File:P4GPIO2.jpg|500px]]

Schematic [[:File:P4GPIO.pdf]]

Gerbers [[:File:P4GPIO25Way.zip]]

BOM [[:File:ibom25way.zip]]

Sorry there is no parts list for Farnell, etc because the parts they supply just change too often, see the BOM for inspiration. The resistors and capacitors are mostly standard 0805 SMD, there are two through hole 100uF 16V electrolytics, non critical as long as they fit and you may want to fit a larger 2512 SMD resistor in the fan supply to slow it down if too loud. The headers are Molex KK254 or equivalent, you only need to fit them if you plan to use them. The PI GPIO header socket is on the bottom of the board, take care not to fit it on the top by mistake! There are two PSU options, only one is needed. The small MCP1584 DC-DC module, as used in the Minitiouner, is probably the easiest to obtain, if you fit this there is no need for the voltage programming resistors R1, R2 and R3 which are needed with the alternative Murata module - see the schematic. Needless to say, the MCP1584 module pot has to be set for 5V before connecting the PI. The reverse protection diode can be almost anything that will survive until the 1.5A PTC fuse activates. I got my PCB mounting DB25 from AliExpress, but they are available from major suppliers. The dimensions vary between suppliers, so be sure to check the PCB footprint for the one you choose. The right one is fairly short and should be flush with the PI USB/Ethernet when you out it in a box.

===G0MJW's HF3 relay board===
Here's Mike's design for a SPDT relay PCB. The relay is General Purpose Relay, [https://uk.farnell.com/axicom-te-connectivity/hf3-56/relay-spdt-220vac-2a/dp/9913599 HF3 Series, High Frequency, Non Latching, SPDT, 12 VDC, 2 A]. Part number is dependant on the voltage in use in circuit. A surface mount diode e.g 1N4148 type, Molex KK connector and 3 SMA to PCB unions complete the build.

[[File:HF3_Relay_board.JPG|250px]]

Gerbers [[:File:HF3_relay_board_gerbers.zip]]

===LNB bias tee and reference injection PCB===

PCB Gerbers for the LNB Bias T and reference injection by Mike G0MJW in CQ-TV263 – or see BATC forum for more details:
https://forum.batc.org.uk/viewtopic.php?f=15&t=3122&p=17416#p17343

[[File:bias.PNG|400px]]

[[:File:BiasTGerbers.zip]]

===M0RNW's G8TA Rx/Tx Changeover Controller Board===
This is v1 designed for a latching relay of up to 6 into 1 ports using an Arduino Nano. Hopefully it features in CQ-TV-279. PCB is intended for rail mounting in a 3U cabinet.

Three SN754410NE H bridge driver ICs are used. The DC-DC boost converters are XL4005 type boards off EBay. U2 can be omitted - it's for an 18V supply to an LNB. Other components - see schematic.

[[File:G8TA_Portsdown_RxTx_Changeover_-1.jpg|400px]]

Gerbers [[:File:Rx-Tx_Changeover_Gerbers.zip]]

Schematic [[:File:RxTx-Changeover.pdf_revised_20230207.pdf]]

Sketch for Arduino Nano[[:File:RxTxChangeoverV1.ino]]

===PE43703 Attenuator Controller===

[[File:IMG 5123 e.png |400px]]

Gerber Files [[:File:PE43703 2025 V 1-0_Gerber.zip]]

Project https://wiki.batc.org.uk/PE43703_2025

===M0RNW's Rx/Tx TTL Changeover Controller Board===
This is v2 designed for a TTL HIGH relay of up to 5 into 1 ports using an Arduino Nano. It is shown in M0YDH's Portsdown 4 transceiver seen in CQ-TV-291. PCB is intended for rail mounting in a 3U cabinet.

[[File:M0RNW_TTL_Coax_Switch_Interface.jpg|400px]]

Gerbers [[:File:TTL_Changeover_v2.zip]]

Schematic [[:File:TTL-Changeover.pdf]]

Sketch for Arduino Nano [[:File:TTL-Changeover_v2.ino]] V2 Arduino IDE - V2.3.6 was used

Bill of Materials [[:File:TTL-Changeover(1).xls]]

Gerber Files

2026-03-27T20:59:51Z

M0YDH: M0RNW's Rx/Tx TTL Changeover Controller Board

This is a centralised index of Gerber Files which have been used for BATC and BATC Members' projects.

No responsibility is accepted for any errors, but they are listed here to promote home construction and experimentation.

Files should be uploaded as .zip files, and should also be referenced from another Wiki page describing the project.

===Ryde Front Panel===

The Ryde Front Panel Push Button PCB as descried here: [[Ryde_Hardware#Ryde_front_panel]]

[[File:Gerbers.zip|thumb|Ryde Front Panel PCBGerbers]]

===ADF4351 PIC Controller===

The ADF4351 PIC Controller described here: [[ADF435x_PIC]]

[[:File:adf435x.zip]]

===DATV Repeater Audio Switch===

The DATV Repeater Audio Switch as described here [[DATV_repeater_audio_switch]]

[[:File:REPEATER I2C AUDIO SWITCH V2022.zip]]

===G0MJW's Ryde board===

This is like a plug in board for the PI4 that provides the 5V PSU, a cooling option and Ryde IO interface. The information is all below. There are two PSU options, only one is required. All fairly simple. These Gerbers are set up for JLC PCB. In theory all you need to do is upload the zip file with the gerbers and select quantity, solder mask colour and postage options. The BOM is an HTML file in the ibom zip.

[[:File:RydeGpioV2.zip]]

[[File:RYDE GPIO 3D.jpg|500px]]

[[File:RydeV2Schematic.jpg|500px]]

[[:File:ibom.zip]]

===G0MJW's PD4 board===

TBC (after CAT22)

This is a PCB to implement a Portsdown 4 with 25 pid connector for interfacing to test equipment and a PTT transistor that can switch light loads. There are also headers for the Langstone.

[[File:P4GPIO2.jpg|500px]]

Schematic [[:File:P4GPIO.pdf]]

Gerbers [[:File:P4GPIO25Way.zip]]

BOM [[:File:ibom25way.zip]]

Sorry there is no parts list for Farnell, etc because the parts they supply just change too often, see the BOM for inspiration. The resistors and capacitors are mostly standard 0805 SMD, there are two through hole 100uF 16V electrolytics, non critical as long as they fit and you may want to fit a larger 2512 SMD resistor in the fan supply to slow it down if too loud. The headers are Molex KK254 or equivalent, you only need to fit them if you plan to use them. The PI GPIO header socket is on the bottom of the board, take care not to fit it on the top by mistake! There are two PSU options, only one is needed. The small MCP1584 DC-DC module, as used in the Minitiouner, is probably the easiest to obtain, if you fit this there is no need for the voltage programming resistors R1, R2 and R3 which are needed with the alternative Murata module - see the schematic. Needless to say, the MCP1584 module pot has to be set for 5V before connecting the PI. The reverse protection diode can be almost anything that will survive until the 1.5A PTC fuse activates. I got my PCB mounting DB25 from AliExpress, but they are available from major suppliers. The dimensions vary between suppliers, so be sure to check the PCB footprint for the one you choose. The right one is fairly short and should be flush with the PI USB/Ethernet when you out it in a box.

===G0MJW's HF3 relay board===
Here's Mike's design for a SPDT relay PCB. The relay is General Purpose Relay, [https://uk.farnell.com/axicom-te-connectivity/hf3-56/relay-spdt-220vac-2a/dp/9913599 HF3 Series, High Frequency, Non Latching, SPDT, 12 VDC, 2 A]. Part number is dependant on the voltage in use in circuit. A surface mount diode e.g 1N4148 type, Molex KK connector and 3 SMA to PCB unions complete the build.

[[File:HF3_Relay_board.JPG|250px]]

Gerbers [[:File:HF3_relay_board_gerbers.zip]]

===LNB bias tee and reference injection PCB===

PCB Gerbers for the LNB Bias T and reference injection by Mike G0MJW in CQ-TV263 – or see BATC forum for more details:
https://forum.batc.org.uk/viewtopic.php?f=15&t=3122&p=17416#p17343

[[File:bias.PNG|400px]]

[[:File:BiasTGerbers.zip]]

===M0RNW's G8TA Rx/Tx Changeover Controller Board===
This is v1 designed for a latching relay of up to 6 into 1 ports using an Arduino Nano. Hopefully it features in CQ-TV-279. PCB is intended for rail mounting in a 3U cabinet.

Three SN754410NE H bridge driver ICs are used. The DC-DC boost converters are XL4005 type boards off EBay. U2 can be omitted - it's for an 18V supply to an LNB. Other components - see schematic.

[[File:G8TA_Portsdown_RxTx_Changeover_-1.jpg|400px]]

Gerbers [[:File:Rx-Tx_Changeover_Gerbers.zip]]

Schematic [[:File:RxTx-Changeover.pdf_revised_20230207.pdf]]

Sketch for Arduino Nano[[:File:RxTxChangeoverV1.ino]]

===PE43703 Attenuator Controller===

[[File:IMG 5123 e.png |400px]]

Gerber Files [[:File:PE43703 2025 V 1-0_Gerber.zip]]

Project https://wiki.batc.org.uk/PE43703_2025

===M0RNW's Rx/Tx TTL Changeover Controller Board===
This is v2 designed for a TTL HIGH relay of up to 5 into 1 ports using an Arduino Nano. It is shown in M0YDH's Portsdown 4 transceiver seen in CQ-TV-291. PCB is intended for rail mounting in a 3U cabinet.

[[File:M0RNW_TTL_Coax_Switch_Interface.jpg|400px]]

Gerbers [[:File:TTL_Changeover_v2.zip]]

Schematic [[:File:TTL-Changeover.pdf]]

Sketch for Arduino Nano[[:File:TTL-Changeover_v2.ino]]

Bill of Materials [[:File:TTL-Changeover(1).xls]]

File:TTL-Changeover v2.ino

2026-03-27T20:58:34Z

M0YDH: Arduino sketch in V2 Arduino IDE, I used V2.3.6

== Summary ==
Arduino sketch in V2 Arduino IDE, I used V2.3.6

File:TTL-Changeover(1).xls

2026-03-27T20:56:32Z

M0YDH: BoM for M0RNW TTL Relay changeober controller

== Summary ==
BoM for M0RNW TTL Relay changeober controller

File:M0RNW TTL Coax Switch Interface.jpg

2026-03-27T20:46:17Z

M0YDH:

File:TTL-Changeover.pdf

2026-03-27T20:40:34Z

M0YDH: Schematic for M0RNW TTL Relay Rx/Tx Changeover controller

== Summary ==
Schematic for M0RNW TTL Relay Rx/Tx Changeover controller

File:TTL Changeover v2.zip

2026-03-27T20:37:24Z

M0YDH: Gerbers for M0RNW TTL relay changeover PCB

== Summary ==
Gerbers for M0RNW TTL relay changeover PCB

Portsdown hardware

2023-12-22T13:46:25Z

M0YDH: /* Audio Capture Device */

This page describes all the hardware modules and interconnections required to build the Portsdown DATV system.

Not all the hardware is required before the transmitter can start to be tested – an incremental approach is described here to allow constructors to gain confidence as they assemble the parts.

===Raspberry Pi ===

'''New builders are recommended to build a Portsdown 4 which, when used with a Adalm Pluto, is integrated with the Langstone Microwave transceiver software enabling an advanced multimode narrowband and DATV transceiver covering 70 MHz to 4 GHz for under £500.
'''

These are available from many suppliers and we suggest you just buy a Raspberry Pi without any additional boards or SD cards as you will be using specific Portsdown hardware and software. If you are starting a new build, the Raspberry Pi 4 Model B with 2 GB of RAM is recommended (4 GB or 8 GB or RAM will work, but costs more for no performance advantage).

The Raspberry Pi 4 can run hot, so using a heatsink case or fan to cool it is recommended.

===Power Supplies ===

You will also need a GOOD 3amp 5v power supply for the Raspberry Pi.

You should power a Pi 4 via the GPIO pins but always power a RPi 3 through the Micro-USB power connector to take advantage of the input protection provided. Use a very short USB cable to your power supply as most of these cables are of very poor quality and cause a significant voltage drop.

If you see a "Lightning Flash" symbol at the top right of your LCD display it means that the voltage at the RPi is too low. You can measure the voltage between the GPIO connector pins 4 and 6.

[[File:flash.jpg|200px]]

A lot of strange problems, such as the Portsdown running very slowly, can be caused by poor PSU volts - the RPi is actually specified for 5.1 volts, so make sure that your PSU delivers enough volts and current. See [https://forum.batc.org.uk/viewtopic.php?t=4856&p=11935#p11935 this post on the BATC forum] for a real user experience!

You may also need a 12 volt DC supply to power the other Portsdown components.

===Micro-SD Card===

You then need an SD card with the Portsdown software on it.

The easiest way is to buy a pre-programmed SD Card from the [https://batc.org.uk/shop/portsdown-transmitter-pre-programmed-sd-card/ BATC shop].

OR if you want to have a go at loading the software yourself you will need to or purchase a '''good quality card''' from another source and follow the instructions described [[Portsdown software|here]]. The 8 GB, 16 GB or 32 GB SanDisk Ultra (the red and grey one) is recommended - DO NOT use cheap copies.

===LCD Touchscreen===

The touchscreen is required to control the transmitter without the use of another computer.

'''Do not buy a touchscreen that connects through the RPi HDMI connector - it is NOT supported.'''

===7" Touchscreen===

The Portsdown 4 is designed to work with the Official Raspberry Pi 7" touchscreen (often referred to as a "7 inch Element 14 touchscreen"). The Portsdown 2020 works best with this screen, but can also use the 3.5 inch screen (below). The Portsdown 4 also supports the DFRobot DFR0550 5 inch touchscreen.

[[File:7_inch_screen.jpg|400px]]

Note that if you use the 7-inch screen, you do not need to connect the 3 data leads between the screen and the RPi - only ground and +5v.

===5" Touchscreen===

The Portsdown 4 (from software release 202203071) supports the DFRobot DFR0550 Touchscreen. However, on initial build, the Portsdown touch map is rotated by 180 degrees. This can be corrected by navigating to Menu 3, System Config, Invert Touchscreen. If you can’t work out exactly where to press, here are the touch points:
# Preset 1 (Menu 3 should then be displayed)
# M2 (the System Configuration Menu should then be displayed)
# Just above Web Control (the reboot question should then be displayed)
# The "d" of inverted (the system should then reboot)

After the reboot, you should again go to Menu 3, System Config and select the 5 inch screen to get a reliable response to touches.

===3.5" OSOYOO DSI Touchscreen===

Hubertus DC1OP has reported that the OSOYOO 3.5 Inch DSI Touchscreen LCD Display also works with the Portsdown 4 in the same way as the DFRobot 5 inch screen - it needs the touchmap to be rotated as for the 5 inch screen. This has not been tested by the development team, so purchase at your own risk!

This screen can be found on Amazon: https://www.amazon.co.uk/OSOYOO-Capacitive-Connector-Resolution-Raspberry/dp/B087WVC1J2

The key enabler is that it is a DSI-connected screen with 800x480 resolution. Note that DPI-connected, or different resolution touchscreens WILL NOT work with the Portsdown.

===3.5" Waveshare Touchscreen===

'''Note this is NOT supported on the Portsdown 4.'''

The other supported touchscreen on Portsdown 2020 is a 3.5 inch diagonal Waveshare Raspberry Pi LCD (Model A, not Model B).

To mount the Waveshare screen away from the RPi, you could use this extension cable: https://thepihut.com/products/adafruit-gpio-extender-cable-for-raspberry-pi-model-a-b-26pin-12-long Just make sure that you triple-check the connections and pin orientation before connecting the screen. They do not tolerate incorrect connection as several of us have found out! Alternatively, you can make one yourself from a discarded 3.5 inch floppy drive and its lead.

Further information on screens can be found here [[Portsdown Displays]] and information on display resolutions can be found here [[Display Resolutions|PAL/NTSC and Display Resolutions]].

Mounting the Waveshare LCD Touchscreen can be a challenge! This 3D print design mounts it flat to the panel: https://www.thingiverse.com/thing:1941701
This 3D print design mounts it at an angle: https://www.thingiverse.com/thing:1920486.

Note that, when mounted, none of the touchscreen sensitive areas should be in contact with the surround.

===GPIO Extender Card===

In the completed unit, there are a number of signals that need to be routed in or out of the GPIO interface on the RPi. Plus we need to break out all 40 pins of the GPIO, and have another connector on top for the Waveshare LCD display (if used). Because of this the Portsdown team have designed a PCB for the job - the blank PCB for this is available from the BATC shop.

Buying an extender card early in the project reduces the chance of damage to the RPi and allows these connections to be made safely.

[[File:screw t.jpg|400px]]

The BATC card is very simple to construct with no components other than plugs and sockets.

For full construction details and a list of suppliers for the plugs and sockets see [[GPIO breakout|the GPIO breakout page]]

You can buy the GPIO Extender Card blank PCB from the [https://batc.org.uk/shop/portsdown-transmitter-gpio-breakout-board-blank-pcb/ Portsdown section in the BATC shop - item 3]

===LimeSDR ===

The Portsdown system can use the LimeSDR Mini (or LimeSDR USB) to provide the modulator and RF generator functions.

[[File:LimeMini.jpg|400px]]

[[Using LimeSDR with Portsdown|See this page]] for more details on using the LimeSDR in a Portsdown system.

===Pluto SDR===

The Portsdown 4 uses the Pluto SDR connected via the USB port to provide the modulator and RF generator functions.

See this page for more details: [[Portsdown_4_Pluto]]

----------------------

'''You now have the components for a fully working Portsdown transmitter!

---------------------

'''''However, you will need a camera and audio input to transmit pictures and sound.'''''

===Raspberry Pi Camera===

If you want to transmit live pictures you will need a camera. The standard V1 or V2 Pi camera gives excellent results but will need mounting in a housing and does not have audio input.

Raspberry Pi 2 Camera: CPC Farnell https://cpc.farnell.com/raspberry-pi/rpi-8mp-camera-board/raspberry-pi-camera-board-v2/dp/SC18701

The Portsdown is only compatible with the Raspberry Pi V1, V2 and HQ cameras. '''It will not operate with the V3 camera or the Global Shutter Camera''', as these require a later version of the operating system which does not support the video encoding features used by the Portsdown transmitter. Raspberry Pi Camera information can be found here: https://www.raspberrypi.com/documentation/accessories/camera.html#hardware-specification

===Optional RPi camera Extension Lead Kit===

The RPi camera gives excellent results, but only comes with a short ribbon cable to connect it to the RPi.

It is possible to use some higher quality HDMI leads (the ground connections all need to be made) to extend the camera lead - this does NOT mean the signal out of the camera is HDMI, it is actually "Camera Serial Interface Type 2 (CSI-2)". We are just using HDMI cable as a useful extension lead.

Kits are available to connect a female HDMI connector to the RPi camera connector, and another female to the camera, allowing the use of domestic 1, 2 and 3m HDMI leads.The maker is Petite Studio

RPi Camera HDMI Lead Extension Kit: https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

In the UK and most of the world it's best to get [https://shop.pimoroni.com/products/pi-camera-hdmi-cable-extension?variant=4585578945 the Petite Studio kit at Pimoroni]. It's called Raspberry Pi Camera HDMI Cable Extension.

There are 2 modifications that can be made to enable lower quality HDMI leads (those without all the ground connections made, or even the CEC wire on pin 13 missing) to be used. Full details of these modifications [[CSI-2 to HDMI|are available here.]]

===WebCams===

Some WebCams work with the Portsdown, but it has proved very difficult to support more than a few specific models. The Portsdown 2020 works with the older (pre-2019) versions of the Logitech C920. The Portsdown 4 works with all (3) versions of the C920 and with the Logitech C170. More details on webcams here [[Portsdown Webcams]].

===Composite Video Capture Device===

The transmitter is also capable of working with a USB-connected “EasyCap” dongle to capture PAL composite video from camcorders and analogue mixers etc.

[[File:Fushicai.JPG|200px]]

There are at least 3 similar devices being marketed under this name on eBay, each with different chipsets, but only the Fushicai "USBTV007" brand is guaranteed to work in all modes on the Portsdown 2020 and Portsdown 4. The Portsdown 4 was modified in Oct 2023 to partially support the "MS2106". The type of EasyCap can be identified by connecting it to the Portsdown 4, selecting “Menu 2”, “File Menu”, “List USB Devices”. Then refer to the table below.

{| class="wikitable"
! Name !! USB Ident !! Compatibility !! Notes
|-
| Fushicai || 1b71:3002 Fushicai... || Portsdown 2020 and Portsdown 4 || BATC Shop pre-2020
|-
| MS2106 || 534d:0021 || Limited with Portsdown 4 only || BATC Shop post-2020
|-
| Arkmicro || 18ec:5555 Arkmicro.... || None ||
|}

Latest versions of the Portsdown 4 will work for Lime and Pluto DVB-S/S2 H264 transmission and streaming with the MS2106 EasyCap that is available from the BATC Shop (2023) https://batc.org.uk/shop/video-capture-device-not-for-use-with-portsdown/. The Chipset in this EasyCap is based on the MS2106 chip from MacroSilicon, hence the name.

The MS2106 has some limitations: The lip sync with this EasyCap is not perfect, but it has not proved possible to improve it, and it needs to be driven with a valid composite video signal otherwise the transmitter fails to start.

===Audio Capture Device===

eBay provides a good source for very cheap audio capture USB dongles, which can provide an audio input to go with the RPi camera. The audio capuure device must be of the type shown here:

[[File:04 USB Audio.png|200px]]

Other stand-alone USB audio capture devices may not work and the software will not be changed to support them. Please don't ask.

This type of audio capture device is also compatible with the Ryde DATV Receiver and the Langstone Microwave transceiver.

The microphone connection is for a T-R-S 3.5mm jack. Be careful when buying e.g. a Lavalier Tie-pin microphone to avoid those with T-R-R-S jacks intended for mobile phone use. These do not produce any audio in the Portsdown!

-----------------------------
'''That completes the basic Portsdown transmitter shopping list'''

---------------------
'''''However, the team has designed some additional components to enable you to build a complete DATV transmit system'''''

===RF Switching===

The complete RF switching arrangement illustrated below allows you to select the output from the Lime SDR or Pluto, adjust the exact level and then route the RF to any one of 8 PAs or transverters. All the blocks in the diagram are optional; however, you can build a very comprehensive system if you want to. Note that the 4-way decode and switch boards can be substituted for the 8-way decode and switch boards.

[[File:20190511 Portsdown RF Switching.jpg|600px]]

===4-Band RF Output Switch===

The Portsdown team have developed a 4-Band RF output switch capable of switching the low level output of the Lime Mini / Pluto to separate amplifiers for the 70, 144, 437 and 1255 MHz bands. Note: due to potential high insertion loss, it is not recommended to use the switch above 23cms.

[[File:Pd out SW.jpg|300px]]

Full details including parts list and schematic are available [[RF output switch|on this wiki page]].

===4-Band Decode Switch===

The Portsdown provides band switching and PTT outputs on the GPIO pins - these outputs need to be decoded to provide an output for each band.

[[File:Band decoder.JPG|200px]]

The Portsdown team have designed a simple board for switching between 4 bands and buffering the PTT signal which can be either constructed on 0.1” perforated board (veroboard) or on a PCB - this can be home etched.
Full details on the board including circuit etc [[PTT and band switching|are available here.]]
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-transmitter-4-band-decode-blank-pcb/ BATC shop - item 5].

===8-Band RF Output Switch===

For those of you who also want to drive Microwave transverters from your Portsdown, the team have developed an 8-Band RF output switch that includes an RF amplifier. It is designed to be used with the Output Attenuator (see below). It will be capable of amplifying the variable level from the attenuator and switching it to separate amplifiers for the 70, 144, 437 and 1255 MHz bands, and to 4 transverters for the higher bands. PCBs are on order and will be available from the BATC Shop.

Full details including parts list and schematic are available [[8-Band RF Output Switch|on this wiki page]].
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-way-rf-output-switch-blank-pcb/ BATC shop - item 9].

===8-Band Decoder===

This 8-band decoder is designed to work with the 8-band RF output switch and the Portsdown software. It will provide switching signals (either always on, or PTT activated) to 4 Power Amplifiers and 4 transverters, and it also enables you to set which VCO filter should be switched in for the 4 transverter outputs. PCBs are on order and will be available from the BATC Shop.

Full details on the board including circuit etc [[8-Band Decoder|are available here.]]
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-band-decode-blank-pcb/ BATC shop - item 7].

===8-Band Decode PIC===

This is the pre=programmed PIC to control the custom designed 8 band decode board for the Portsdown transmitter.

Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-band-decode-pic/ BATC shop - item 8].

===2-Way RF Switch===

Not required for Portsdown 4.

This switch allows you to route the outputs from the Portsdown 2017 Filter Modulator card and a LimeSDR to a single PA, enabling both to be used without reconfiguration. Full details on this Wiki page [[2-Way RF Switch]].

===Filters and PA drivers===

It is absolutely essential that the Portsdown transmitter output is followed by suitable bandpass filters.
These are not included as part of the project but a [[Filters|number of designs and suppliers are listed here.]]

===Output Attenuator===

Although NOT required when using the Lime Mini or Pluto SDR, the Portsdown can use an electronically switched attenuator to adjust the transmit drive level for each band. Attenuators based on the PE4302, HMC1119 or PE43703 (preferred) are supported.

[[File:PE43073 post-mod small.jpg|400px]]

These attenuators are available on eBay. Full details and wiring instructions are detailed here: [[Output Attenuator]].

Portsdown hardware

2023-12-22T13:46:07Z

M0YDH: /* Audio Capture Device */

This page describes all the hardware modules and interconnections required to build the Portsdown DATV system.

Not all the hardware is required before the transmitter can start to be tested – an incremental approach is described here to allow constructors to gain confidence as they assemble the parts.

===Raspberry Pi ===

'''New builders are recommended to build a Portsdown 4 which, when used with a Adalm Pluto, is integrated with the Langstone Microwave transceiver software enabling an advanced multimode narrowband and DATV transceiver covering 70 MHz to 4 GHz for under £500.
'''

These are available from many suppliers and we suggest you just buy a Raspberry Pi without any additional boards or SD cards as you will be using specific Portsdown hardware and software. If you are starting a new build, the Raspberry Pi 4 Model B with 2 GB of RAM is recommended (4 GB or 8 GB or RAM will work, but costs more for no performance advantage).

The Raspberry Pi 4 can run hot, so using a heatsink case or fan to cool it is recommended.

===Power Supplies ===

You will also need a GOOD 3amp 5v power supply for the Raspberry Pi.

You should power a Pi 4 via the GPIO pins but always power a RPi 3 through the Micro-USB power connector to take advantage of the input protection provided. Use a very short USB cable to your power supply as most of these cables are of very poor quality and cause a significant voltage drop.

If you see a "Lightning Flash" symbol at the top right of your LCD display it means that the voltage at the RPi is too low. You can measure the voltage between the GPIO connector pins 4 and 6.

[[File:flash.jpg|200px]]

A lot of strange problems, such as the Portsdown running very slowly, can be caused by poor PSU volts - the RPi is actually specified for 5.1 volts, so make sure that your PSU delivers enough volts and current. See [https://forum.batc.org.uk/viewtopic.php?t=4856&p=11935#p11935 this post on the BATC forum] for a real user experience!

You may also need a 12 volt DC supply to power the other Portsdown components.

===Micro-SD Card===

You then need an SD card with the Portsdown software on it.

The easiest way is to buy a pre-programmed SD Card from the [https://batc.org.uk/shop/portsdown-transmitter-pre-programmed-sd-card/ BATC shop].

OR if you want to have a go at loading the software yourself you will need to or purchase a '''good quality card''' from another source and follow the instructions described [[Portsdown software|here]]. The 8 GB, 16 GB or 32 GB SanDisk Ultra (the red and grey one) is recommended - DO NOT use cheap copies.

===LCD Touchscreen===

The touchscreen is required to control the transmitter without the use of another computer.

'''Do not buy a touchscreen that connects through the RPi HDMI connector - it is NOT supported.'''

===7" Touchscreen===

The Portsdown 4 is designed to work with the Official Raspberry Pi 7" touchscreen (often referred to as a "7 inch Element 14 touchscreen"). The Portsdown 2020 works best with this screen, but can also use the 3.5 inch screen (below). The Portsdown 4 also supports the DFRobot DFR0550 5 inch touchscreen.

[[File:7_inch_screen.jpg|400px]]

Note that if you use the 7-inch screen, you do not need to connect the 3 data leads between the screen and the RPi - only ground and +5v.

===5" Touchscreen===

The Portsdown 4 (from software release 202203071) supports the DFRobot DFR0550 Touchscreen. However, on initial build, the Portsdown touch map is rotated by 180 degrees. This can be corrected by navigating to Menu 3, System Config, Invert Touchscreen. If you can’t work out exactly where to press, here are the touch points:
# Preset 1 (Menu 3 should then be displayed)
# M2 (the System Configuration Menu should then be displayed)
# Just above Web Control (the reboot question should then be displayed)
# The "d" of inverted (the system should then reboot)

After the reboot, you should again go to Menu 3, System Config and select the 5 inch screen to get a reliable response to touches.

===3.5" OSOYOO DSI Touchscreen===

Hubertus DC1OP has reported that the OSOYOO 3.5 Inch DSI Touchscreen LCD Display also works with the Portsdown 4 in the same way as the DFRobot 5 inch screen - it needs the touchmap to be rotated as for the 5 inch screen. This has not been tested by the development team, so purchase at your own risk!

This screen can be found on Amazon: https://www.amazon.co.uk/OSOYOO-Capacitive-Connector-Resolution-Raspberry/dp/B087WVC1J2

The key enabler is that it is a DSI-connected screen with 800x480 resolution. Note that DPI-connected, or different resolution touchscreens WILL NOT work with the Portsdown.

===3.5" Waveshare Touchscreen===

'''Note this is NOT supported on the Portsdown 4.'''

The other supported touchscreen on Portsdown 2020 is a 3.5 inch diagonal Waveshare Raspberry Pi LCD (Model A, not Model B).

To mount the Waveshare screen away from the RPi, you could use this extension cable: https://thepihut.com/products/adafruit-gpio-extender-cable-for-raspberry-pi-model-a-b-26pin-12-long Just make sure that you triple-check the connections and pin orientation before connecting the screen. They do not tolerate incorrect connection as several of us have found out! Alternatively, you can make one yourself from a discarded 3.5 inch floppy drive and its lead.

Further information on screens can be found here [[Portsdown Displays]] and information on display resolutions can be found here [[Display Resolutions|PAL/NTSC and Display Resolutions]].

Mounting the Waveshare LCD Touchscreen can be a challenge! This 3D print design mounts it flat to the panel: https://www.thingiverse.com/thing:1941701
This 3D print design mounts it at an angle: https://www.thingiverse.com/thing:1920486.

Note that, when mounted, none of the touchscreen sensitive areas should be in contact with the surround.

===GPIO Extender Card===

In the completed unit, there are a number of signals that need to be routed in or out of the GPIO interface on the RPi. Plus we need to break out all 40 pins of the GPIO, and have another connector on top for the Waveshare LCD display (if used). Because of this the Portsdown team have designed a PCB for the job - the blank PCB for this is available from the BATC shop.

Buying an extender card early in the project reduces the chance of damage to the RPi and allows these connections to be made safely.

[[File:screw t.jpg|400px]]

The BATC card is very simple to construct with no components other than plugs and sockets.

For full construction details and a list of suppliers for the plugs and sockets see [[GPIO breakout|the GPIO breakout page]]

You can buy the GPIO Extender Card blank PCB from the [https://batc.org.uk/shop/portsdown-transmitter-gpio-breakout-board-blank-pcb/ Portsdown section in the BATC shop - item 3]

===LimeSDR ===

The Portsdown system can use the LimeSDR Mini (or LimeSDR USB) to provide the modulator and RF generator functions.

[[File:LimeMini.jpg|400px]]

[[Using LimeSDR with Portsdown|See this page]] for more details on using the LimeSDR in a Portsdown system.

===Pluto SDR===

The Portsdown 4 uses the Pluto SDR connected via the USB port to provide the modulator and RF generator functions.

See this page for more details: [[Portsdown_4_Pluto]]

----------------------

'''You now have the components for a fully working Portsdown transmitter!

---------------------

'''''However, you will need a camera and audio input to transmit pictures and sound.'''''

===Raspberry Pi Camera===

If you want to transmit live pictures you will need a camera. The standard V1 or V2 Pi camera gives excellent results but will need mounting in a housing and does not have audio input.

Raspberry Pi 2 Camera: CPC Farnell https://cpc.farnell.com/raspberry-pi/rpi-8mp-camera-board/raspberry-pi-camera-board-v2/dp/SC18701

The Portsdown is only compatible with the Raspberry Pi V1, V2 and HQ cameras. '''It will not operate with the V3 camera or the Global Shutter Camera''', as these require a later version of the operating system which does not support the video encoding features used by the Portsdown transmitter. Raspberry Pi Camera information can be found here: https://www.raspberrypi.com/documentation/accessories/camera.html#hardware-specification

===Optional RPi camera Extension Lead Kit===

The RPi camera gives excellent results, but only comes with a short ribbon cable to connect it to the RPi.

It is possible to use some higher quality HDMI leads (the ground connections all need to be made) to extend the camera lead - this does NOT mean the signal out of the camera is HDMI, it is actually "Camera Serial Interface Type 2 (CSI-2)". We are just using HDMI cable as a useful extension lead.

Kits are available to connect a female HDMI connector to the RPi camera connector, and another female to the camera, allowing the use of domestic 1, 2 and 3m HDMI leads.The maker is Petite Studio

RPi Camera HDMI Lead Extension Kit: https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

In the UK and most of the world it's best to get [https://shop.pimoroni.com/products/pi-camera-hdmi-cable-extension?variant=4585578945 the Petite Studio kit at Pimoroni]. It's called Raspberry Pi Camera HDMI Cable Extension.

There are 2 modifications that can be made to enable lower quality HDMI leads (those without all the ground connections made, or even the CEC wire on pin 13 missing) to be used. Full details of these modifications [[CSI-2 to HDMI|are available here.]]

===WebCams===

Some WebCams work with the Portsdown, but it has proved very difficult to support more than a few specific models. The Portsdown 2020 works with the older (pre-2019) versions of the Logitech C920. The Portsdown 4 works with all (3) versions of the C920 and with the Logitech C170. More details on webcams here [[Portsdown Webcams]].

===Composite Video Capture Device===

The transmitter is also capable of working with a USB-connected “EasyCap” dongle to capture PAL composite video from camcorders and analogue mixers etc.

[[File:Fushicai.JPG|200px]]

There are at least 3 similar devices being marketed under this name on eBay, each with different chipsets, but only the Fushicai "USBTV007" brand is guaranteed to work in all modes on the Portsdown 2020 and Portsdown 4. The Portsdown 4 was modified in Oct 2023 to partially support the "MS2106". The type of EasyCap can be identified by connecting it to the Portsdown 4, selecting “Menu 2”, “File Menu”, “List USB Devices”. Then refer to the table below.

{| class="wikitable"
! Name !! USB Ident !! Compatibility !! Notes
|-
| Fushicai || 1b71:3002 Fushicai... || Portsdown 2020 and Portsdown 4 || BATC Shop pre-2020
|-
| MS2106 || 534d:0021 || Limited with Portsdown 4 only || BATC Shop post-2020
|-
| Arkmicro || 18ec:5555 Arkmicro.... || None ||
|}

Latest versions of the Portsdown 4 will work for Lime and Pluto DVB-S/S2 H264 transmission and streaming with the MS2106 EasyCap that is available from the BATC Shop (2023) https://batc.org.uk/shop/video-capture-device-not-for-use-with-portsdown/. The Chipset in this EasyCap is based on the MS2106 chip from MacroSilicon, hence the name.

The MS2106 has some limitations: The lip sync with this EasyCap is not perfect, but it has not proved possible to improve it, and it needs to be driven with a valid composite video signal otherwise the transmitter fails to start.

===Audio Capture Device===

eBay provides a good source for very cheap audio capture USB dongles, which can provide an audio input to go with the RPi camera. The audio capuure device must be of the type shown here:

[[File:04 USB Audio.png|200px]]

Other stand-alone USB audio capture devices may not work and the software will not be changed to support them. Please don't ask.

This type of audio capture device is also compatible with the Ryde DATV Receiver and the Langstone Microwave transceiver.

The microphone connection is for a T-R-S 3.5mm jack. Be careful when buying e.g. a Lavelier Tie-pin microphone to avoid those with T-R-R-S jacks intended for mobile phone use. These do not produce any audio in the Portsdown!

-----------------------------
'''That completes the basic Portsdown transmitter shopping list'''

---------------------
'''''However, the team has designed some additional components to enable you to build a complete DATV transmit system'''''

===RF Switching===

The complete RF switching arrangement illustrated below allows you to select the output from the Lime SDR or Pluto, adjust the exact level and then route the RF to any one of 8 PAs or transverters. All the blocks in the diagram are optional; however, you can build a very comprehensive system if you want to. Note that the 4-way decode and switch boards can be substituted for the 8-way decode and switch boards.

[[File:20190511 Portsdown RF Switching.jpg|600px]]

===4-Band RF Output Switch===

The Portsdown team have developed a 4-Band RF output switch capable of switching the low level output of the Lime Mini / Pluto to separate amplifiers for the 70, 144, 437 and 1255 MHz bands. Note: due to potential high insertion loss, it is not recommended to use the switch above 23cms.

[[File:Pd out SW.jpg|300px]]

Full details including parts list and schematic are available [[RF output switch|on this wiki page]].

===4-Band Decode Switch===

The Portsdown provides band switching and PTT outputs on the GPIO pins - these outputs need to be decoded to provide an output for each band.

[[File:Band decoder.JPG|200px]]

The Portsdown team have designed a simple board for switching between 4 bands and buffering the PTT signal which can be either constructed on 0.1” perforated board (veroboard) or on a PCB - this can be home etched.
Full details on the board including circuit etc [[PTT and band switching|are available here.]]
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-transmitter-4-band-decode-blank-pcb/ BATC shop - item 5].

===8-Band RF Output Switch===

For those of you who also want to drive Microwave transverters from your Portsdown, the team have developed an 8-Band RF output switch that includes an RF amplifier. It is designed to be used with the Output Attenuator (see below). It will be capable of amplifying the variable level from the attenuator and switching it to separate amplifiers for the 70, 144, 437 and 1255 MHz bands, and to 4 transverters for the higher bands. PCBs are on order and will be available from the BATC Shop.

Full details including parts list and schematic are available [[8-Band RF Output Switch|on this wiki page]].
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-way-rf-output-switch-blank-pcb/ BATC shop - item 9].

===8-Band Decoder===

This 8-band decoder is designed to work with the 8-band RF output switch and the Portsdown software. It will provide switching signals (either always on, or PTT activated) to 4 Power Amplifiers and 4 transverters, and it also enables you to set which VCO filter should be switched in for the 4 transverter outputs. PCBs are on order and will be available from the BATC Shop.

Full details on the board including circuit etc [[8-Band Decoder|are available here.]]
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-band-decode-blank-pcb/ BATC shop - item 7].

===8-Band Decode PIC===

This is the pre=programmed PIC to control the custom designed 8 band decode board for the Portsdown transmitter.

Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-band-decode-pic/ BATC shop - item 8].

===2-Way RF Switch===

Not required for Portsdown 4.

This switch allows you to route the outputs from the Portsdown 2017 Filter Modulator card and a LimeSDR to a single PA, enabling both to be used without reconfiguration. Full details on this Wiki page [[2-Way RF Switch]].

===Filters and PA drivers===

It is absolutely essential that the Portsdown transmitter output is followed by suitable bandpass filters.
These are not included as part of the project but a [[Filters|number of designs and suppliers are listed here.]]

===Output Attenuator===

Although NOT required when using the Lime Mini or Pluto SDR, the Portsdown can use an electronically switched attenuator to adjust the transmit drive level for each band. Attenuators based on the PE4302, HMC1119 or PE43703 (preferred) are supported.

[[File:PE43073 post-mod small.jpg|400px]]

These attenuators are available on eBay. Full details and wiring instructions are detailed here: [[Output Attenuator]].

Portsdown hardware

2023-12-22T13:43:18Z

M0YDH: /* Audio Capture Device */

This page describes all the hardware modules and interconnections required to build the Portsdown DATV system.

Not all the hardware is required before the transmitter can start to be tested – an incremental approach is described here to allow constructors to gain confidence as they assemble the parts.

===Raspberry Pi ===

'''New builders are recommended to build a Portsdown 4 which, when used with a Adalm Pluto, is integrated with the Langstone Microwave transceiver software enabling an advanced multimode narrowband and DATV transceiver covering 70 MHz to 4 GHz for under £500.
'''

These are available from many suppliers and we suggest you just buy a Raspberry Pi without any additional boards or SD cards as you will be using specific Portsdown hardware and software. If you are starting a new build, the Raspberry Pi 4 Model B with 2 GB of RAM is recommended (4 GB or 8 GB or RAM will work, but costs more for no performance advantage).

The Raspberry Pi 4 can run hot, so using a heatsink case or fan to cool it is recommended.

===Power Supplies ===

You will also need a GOOD 3amp 5v power supply for the Raspberry Pi.

You should power a Pi 4 via the GPIO pins but always power a RPi 3 through the Micro-USB power connector to take advantage of the input protection provided. Use a very short USB cable to your power supply as most of these cables are of very poor quality and cause a significant voltage drop.

If you see a "Lightning Flash" symbol at the top right of your LCD display it means that the voltage at the RPi is too low. You can measure the voltage between the GPIO connector pins 4 and 6.

[[File:flash.jpg|200px]]

A lot of strange problems, such as the Portsdown running very slowly, can be caused by poor PSU volts - the RPi is actually specified for 5.1 volts, so make sure that your PSU delivers enough volts and current. See [https://forum.batc.org.uk/viewtopic.php?t=4856&p=11935#p11935 this post on the BATC forum] for a real user experience!

You may also need a 12 volt DC supply to power the other Portsdown components.

===Micro-SD Card===

You then need an SD card with the Portsdown software on it.

The easiest way is to buy a pre-programmed SD Card from the [https://batc.org.uk/shop/portsdown-transmitter-pre-programmed-sd-card/ BATC shop].

OR if you want to have a go at loading the software yourself you will need to or purchase a '''good quality card''' from another source and follow the instructions described [[Portsdown software|here]]. The 8 GB, 16 GB or 32 GB SanDisk Ultra (the red and grey one) is recommended - DO NOT use cheap copies.

===LCD Touchscreen===

The touchscreen is required to control the transmitter without the use of another computer.

'''Do not buy a touchscreen that connects through the RPi HDMI connector - it is NOT supported.'''

===7" Touchscreen===

The Portsdown 4 is designed to work with the Official Raspberry Pi 7" touchscreen (often referred to as a "7 inch Element 14 touchscreen"). The Portsdown 2020 works best with this screen, but can also use the 3.5 inch screen (below). The Portsdown 4 also supports the DFRobot DFR0550 5 inch touchscreen.

[[File:7_inch_screen.jpg|400px]]

Note that if you use the 7-inch screen, you do not need to connect the 3 data leads between the screen and the RPi - only ground and +5v.

===5" Touchscreen===

The Portsdown 4 (from software release 202203071) supports the DFRobot DFR0550 Touchscreen. However, on initial build, the Portsdown touch map is rotated by 180 degrees. This can be corrected by navigating to Menu 3, System Config, Invert Touchscreen. If you can’t work out exactly where to press, here are the touch points:
# Preset 1 (Menu 3 should then be displayed)
# M2 (the System Configuration Menu should then be displayed)
# Just above Web Control (the reboot question should then be displayed)
# The "d" of inverted (the system should then reboot)

After the reboot, you should again go to Menu 3, System Config and select the 5 inch screen to get a reliable response to touches.

===3.5" OSOYOO DSI Touchscreen===

Hubertus DC1OP has reported that the OSOYOO 3.5 Inch DSI Touchscreen LCD Display also works with the Portsdown 4 in the same way as the DFRobot 5 inch screen - it needs the touchmap to be rotated as for the 5 inch screen. This has not been tested by the development team, so purchase at your own risk!

This screen can be found on Amazon: https://www.amazon.co.uk/OSOYOO-Capacitive-Connector-Resolution-Raspberry/dp/B087WVC1J2

The key enabler is that it is a DSI-connected screen with 800x480 resolution. Note that DPI-connected, or different resolution touchscreens WILL NOT work with the Portsdown.

===3.5" Waveshare Touchscreen===

'''Note this is NOT supported on the Portsdown 4.'''

The other supported touchscreen on Portsdown 2020 is a 3.5 inch diagonal Waveshare Raspberry Pi LCD (Model A, not Model B).

To mount the Waveshare screen away from the RPi, you could use this extension cable: https://thepihut.com/products/adafruit-gpio-extender-cable-for-raspberry-pi-model-a-b-26pin-12-long Just make sure that you triple-check the connections and pin orientation before connecting the screen. They do not tolerate incorrect connection as several of us have found out! Alternatively, you can make one yourself from a discarded 3.5 inch floppy drive and its lead.

Further information on screens can be found here [[Portsdown Displays]] and information on display resolutions can be found here [[Display Resolutions|PAL/NTSC and Display Resolutions]].

Mounting the Waveshare LCD Touchscreen can be a challenge! This 3D print design mounts it flat to the panel: https://www.thingiverse.com/thing:1941701
This 3D print design mounts it at an angle: https://www.thingiverse.com/thing:1920486.

Note that, when mounted, none of the touchscreen sensitive areas should be in contact with the surround.

===GPIO Extender Card===

In the completed unit, there are a number of signals that need to be routed in or out of the GPIO interface on the RPi. Plus we need to break out all 40 pins of the GPIO, and have another connector on top for the Waveshare LCD display (if used). Because of this the Portsdown team have designed a PCB for the job - the blank PCB for this is available from the BATC shop.

Buying an extender card early in the project reduces the chance of damage to the RPi and allows these connections to be made safely.

[[File:screw t.jpg|400px]]

The BATC card is very simple to construct with no components other than plugs and sockets.

For full construction details and a list of suppliers for the plugs and sockets see [[GPIO breakout|the GPIO breakout page]]

You can buy the GPIO Extender Card blank PCB from the [https://batc.org.uk/shop/portsdown-transmitter-gpio-breakout-board-blank-pcb/ Portsdown section in the BATC shop - item 3]

===LimeSDR ===

The Portsdown system can use the LimeSDR Mini (or LimeSDR USB) to provide the modulator and RF generator functions.

[[File:LimeMini.jpg|400px]]

[[Using LimeSDR with Portsdown|See this page]] for more details on using the LimeSDR in a Portsdown system.

===Pluto SDR===

The Portsdown 4 uses the Pluto SDR connected via the USB port to provide the modulator and RF generator functions.

See this page for more details: [[Portsdown_4_Pluto]]

----------------------

'''You now have the components for a fully working Portsdown transmitter!

---------------------

'''''However, you will need a camera and audio input to transmit pictures and sound.'''''

===Raspberry Pi Camera===

If you want to transmit live pictures you will need a camera. The standard V1 or V2 Pi camera gives excellent results but will need mounting in a housing and does not have audio input.

Raspberry Pi 2 Camera: CPC Farnell https://cpc.farnell.com/raspberry-pi/rpi-8mp-camera-board/raspberry-pi-camera-board-v2/dp/SC18701

The Portsdown is only compatible with the Raspberry Pi V1, V2 and HQ cameras. '''It will not operate with the V3 camera or the Global Shutter Camera''', as these require a later version of the operating system which does not support the video encoding features used by the Portsdown transmitter. Raspberry Pi Camera information can be found here: https://www.raspberrypi.com/documentation/accessories/camera.html#hardware-specification

===Optional RPi camera Extension Lead Kit===

The RPi camera gives excellent results, but only comes with a short ribbon cable to connect it to the RPi.

It is possible to use some higher quality HDMI leads (the ground connections all need to be made) to extend the camera lead - this does NOT mean the signal out of the camera is HDMI, it is actually "Camera Serial Interface Type 2 (CSI-2)". We are just using HDMI cable as a useful extension lead.

Kits are available to connect a female HDMI connector to the RPi camera connector, and another female to the camera, allowing the use of domestic 1, 2 and 3m HDMI leads.The maker is Petite Studio

RPi Camera HDMI Lead Extension Kit: https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

In the UK and most of the world it's best to get [https://shop.pimoroni.com/products/pi-camera-hdmi-cable-extension?variant=4585578945 the Petite Studio kit at Pimoroni]. It's called Raspberry Pi Camera HDMI Cable Extension.

There are 2 modifications that can be made to enable lower quality HDMI leads (those without all the ground connections made, or even the CEC wire on pin 13 missing) to be used. Full details of these modifications [[CSI-2 to HDMI|are available here.]]

===WebCams===

Some WebCams work with the Portsdown, but it has proved very difficult to support more than a few specific models. The Portsdown 2020 works with the older (pre-2019) versions of the Logitech C920. The Portsdown 4 works with all (3) versions of the C920 and with the Logitech C170. More details on webcams here [[Portsdown Webcams]].

===Composite Video Capture Device===

The transmitter is also capable of working with a USB-connected “EasyCap” dongle to capture PAL composite video from camcorders and analogue mixers etc.

[[File:Fushicai.JPG|200px]]

There are at least 3 similar devices being marketed under this name on eBay, each with different chipsets, but only the Fushicai "USBTV007" brand is guaranteed to work in all modes on the Portsdown 2020 and Portsdown 4. The Portsdown 4 was modified in Oct 2023 to partially support the "MS2106". The type of EasyCap can be identified by connecting it to the Portsdown 4, selecting “Menu 2”, “File Menu”, “List USB Devices”. Then refer to the table below.

{| class="wikitable"
! Name !! USB Ident !! Compatibility !! Notes
|-
| Fushicai || 1b71:3002 Fushicai... || Portsdown 2020 and Portsdown 4 || BATC Shop pre-2020
|-
| MS2106 || 534d:0021 || Limited with Portsdown 4 only || BATC Shop post-2020
|-
| Arkmicro || 18ec:5555 Arkmicro.... || None ||
|}

Latest versions of the Portsdown 4 will work for Lime and Pluto DVB-S/S2 H264 transmission and streaming with the MS2106 EasyCap that is available from the BATC Shop (2023) https://batc.org.uk/shop/video-capture-device-not-for-use-with-portsdown/. The Chipset in this EasyCap is based on the MS2106 chip from MacroSilicon, hence the name.

The MS2106 has some limitations: The lip sync with this EasyCap is not perfect, but it has not proved possible to improve it, and it needs to be driven with a valid composite video signal otherwise the transmitter fails to start.

===Audio Capture Device===

eBay provides a good source for very cheap audio capture USB dongles, which can provide an audio input to go with the RPi camera. The audio capuure device must be of the type shown here:

[[File:04 USB Audio.png|200px]]

Other stand-alone USB audio capture devices may not work and the software will not be changed to support them. Please don't ask.

This type of audio capture device is also compatible with the Ryde DATV Receiver and the Langstone Microwave transceiver.

The microphone connection is for a T-R-S 3.5mm jack. Be careful when buying e.g. a Lavellier Tie-pin microphone to avoid those with T-R-R-S jacks. These do not produce any audio in the Portsdown!

-----------------------------
'''That completes the basic Portsdown transmitter shopping list'''

---------------------
'''''However, the team has designed some additional components to enable you to build a complete DATV transmit system'''''

===RF Switching===

The complete RF switching arrangement illustrated below allows you to select the output from the Lime SDR or Pluto, adjust the exact level and then route the RF to any one of 8 PAs or transverters. All the blocks in the diagram are optional; however, you can build a very comprehensive system if you want to. Note that the 4-way decode and switch boards can be substituted for the 8-way decode and switch boards.

[[File:20190511 Portsdown RF Switching.jpg|600px]]

===4-Band RF Output Switch===

The Portsdown team have developed a 4-Band RF output switch capable of switching the low level output of the Lime Mini / Pluto to separate amplifiers for the 70, 144, 437 and 1255 MHz bands. Note: due to potential high insertion loss, it is not recommended to use the switch above 23cms.

[[File:Pd out SW.jpg|300px]]

Full details including parts list and schematic are available [[RF output switch|on this wiki page]].

===4-Band Decode Switch===

The Portsdown provides band switching and PTT outputs on the GPIO pins - these outputs need to be decoded to provide an output for each band.

[[File:Band decoder.JPG|200px]]

The Portsdown team have designed a simple board for switching between 4 bands and buffering the PTT signal which can be either constructed on 0.1” perforated board (veroboard) or on a PCB - this can be home etched.
Full details on the board including circuit etc [[PTT and band switching|are available here.]]
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-transmitter-4-band-decode-blank-pcb/ BATC shop - item 5].

===8-Band RF Output Switch===

For those of you who also want to drive Microwave transverters from your Portsdown, the team have developed an 8-Band RF output switch that includes an RF amplifier. It is designed to be used with the Output Attenuator (see below). It will be capable of amplifying the variable level from the attenuator and switching it to separate amplifiers for the 70, 144, 437 and 1255 MHz bands, and to 4 transverters for the higher bands. PCBs are on order and will be available from the BATC Shop.

Full details including parts list and schematic are available [[8-Band RF Output Switch|on this wiki page]].
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-way-rf-output-switch-blank-pcb/ BATC shop - item 9].

===8-Band Decoder===

This 8-band decoder is designed to work with the 8-band RF output switch and the Portsdown software. It will provide switching signals (either always on, or PTT activated) to 4 Power Amplifiers and 4 transverters, and it also enables you to set which VCO filter should be switched in for the 4 transverter outputs. PCBs are on order and will be available from the BATC Shop.

Full details on the board including circuit etc [[8-Band Decoder|are available here.]]
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-band-decode-blank-pcb/ BATC shop - item 7].

===8-Band Decode PIC===

This is the pre=programmed PIC to control the custom designed 8 band decode board for the Portsdown transmitter.

Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-band-decode-pic/ BATC shop - item 8].

===2-Way RF Switch===

Not required for Portsdown 4.

This switch allows you to route the outputs from the Portsdown 2017 Filter Modulator card and a LimeSDR to a single PA, enabling both to be used without reconfiguration. Full details on this Wiki page [[2-Way RF Switch]].

===Filters and PA drivers===

It is absolutely essential that the Portsdown transmitter output is followed by suitable bandpass filters.
These are not included as part of the project but a [[Filters|number of designs and suppliers are listed here.]]

===Output Attenuator===

Although NOT required when using the Lime Mini or Pluto SDR, the Portsdown can use an electronically switched attenuator to adjust the transmit drive level for each band. Attenuators based on the PE4302, HMC1119 or PE43703 (preferred) are supported.

[[File:PE43073 post-mod small.jpg|400px]]

These attenuators are available on eBay. Full details and wiring instructions are detailed here: [[Output Attenuator]].

Portsdown hardware

2023-12-22T13:42:41Z

M0YDH: /* Audio Capture Device */ T-R-S microphones

This page describes all the hardware modules and interconnections required to build the Portsdown DATV system.

Not all the hardware is required before the transmitter can start to be tested – an incremental approach is described here to allow constructors to gain confidence as they assemble the parts.

===Raspberry Pi ===

'''New builders are recommended to build a Portsdown 4 which, when used with a Adalm Pluto, is integrated with the Langstone Microwave transceiver software enabling an advanced multimode narrowband and DATV transceiver covering 70 MHz to 4 GHz for under £500.
'''

These are available from many suppliers and we suggest you just buy a Raspberry Pi without any additional boards or SD cards as you will be using specific Portsdown hardware and software. If you are starting a new build, the Raspberry Pi 4 Model B with 2 GB of RAM is recommended (4 GB or 8 GB or RAM will work, but costs more for no performance advantage).

The Raspberry Pi 4 can run hot, so using a heatsink case or fan to cool it is recommended.

===Power Supplies ===

You will also need a GOOD 3amp 5v power supply for the Raspberry Pi.

You should power a Pi 4 via the GPIO pins but always power a RPi 3 through the Micro-USB power connector to take advantage of the input protection provided. Use a very short USB cable to your power supply as most of these cables are of very poor quality and cause a significant voltage drop.

If you see a "Lightning Flash" symbol at the top right of your LCD display it means that the voltage at the RPi is too low. You can measure the voltage between the GPIO connector pins 4 and 6.

[[File:flash.jpg|200px]]

A lot of strange problems, such as the Portsdown running very slowly, can be caused by poor PSU volts - the RPi is actually specified for 5.1 volts, so make sure that your PSU delivers enough volts and current. See [https://forum.batc.org.uk/viewtopic.php?t=4856&p=11935#p11935 this post on the BATC forum] for a real user experience!

You may also need a 12 volt DC supply to power the other Portsdown components.

===Micro-SD Card===

You then need an SD card with the Portsdown software on it.

The easiest way is to buy a pre-programmed SD Card from the [https://batc.org.uk/shop/portsdown-transmitter-pre-programmed-sd-card/ BATC shop].

OR if you want to have a go at loading the software yourself you will need to or purchase a '''good quality card''' from another source and follow the instructions described [[Portsdown software|here]]. The 8 GB, 16 GB or 32 GB SanDisk Ultra (the red and grey one) is recommended - DO NOT use cheap copies.

===LCD Touchscreen===

The touchscreen is required to control the transmitter without the use of another computer.

'''Do not buy a touchscreen that connects through the RPi HDMI connector - it is NOT supported.'''

===7" Touchscreen===

The Portsdown 4 is designed to work with the Official Raspberry Pi 7" touchscreen (often referred to as a "7 inch Element 14 touchscreen"). The Portsdown 2020 works best with this screen, but can also use the 3.5 inch screen (below). The Portsdown 4 also supports the DFRobot DFR0550 5 inch touchscreen.

[[File:7_inch_screen.jpg|400px]]

Note that if you use the 7-inch screen, you do not need to connect the 3 data leads between the screen and the RPi - only ground and +5v.

===5" Touchscreen===

The Portsdown 4 (from software release 202203071) supports the DFRobot DFR0550 Touchscreen. However, on initial build, the Portsdown touch map is rotated by 180 degrees. This can be corrected by navigating to Menu 3, System Config, Invert Touchscreen. If you can’t work out exactly where to press, here are the touch points:
# Preset 1 (Menu 3 should then be displayed)
# M2 (the System Configuration Menu should then be displayed)
# Just above Web Control (the reboot question should then be displayed)
# The "d" of inverted (the system should then reboot)

After the reboot, you should again go to Menu 3, System Config and select the 5 inch screen to get a reliable response to touches.

===3.5" OSOYOO DSI Touchscreen===

Hubertus DC1OP has reported that the OSOYOO 3.5 Inch DSI Touchscreen LCD Display also works with the Portsdown 4 in the same way as the DFRobot 5 inch screen - it needs the touchmap to be rotated as for the 5 inch screen. This has not been tested by the development team, so purchase at your own risk!

This screen can be found on Amazon: https://www.amazon.co.uk/OSOYOO-Capacitive-Connector-Resolution-Raspberry/dp/B087WVC1J2

The key enabler is that it is a DSI-connected screen with 800x480 resolution. Note that DPI-connected, or different resolution touchscreens WILL NOT work with the Portsdown.

===3.5" Waveshare Touchscreen===

'''Note this is NOT supported on the Portsdown 4.'''

The other supported touchscreen on Portsdown 2020 is a 3.5 inch diagonal Waveshare Raspberry Pi LCD (Model A, not Model B).

To mount the Waveshare screen away from the RPi, you could use this extension cable: https://thepihut.com/products/adafruit-gpio-extender-cable-for-raspberry-pi-model-a-b-26pin-12-long Just make sure that you triple-check the connections and pin orientation before connecting the screen. They do not tolerate incorrect connection as several of us have found out! Alternatively, you can make one yourself from a discarded 3.5 inch floppy drive and its lead.

Further information on screens can be found here [[Portsdown Displays]] and information on display resolutions can be found here [[Display Resolutions|PAL/NTSC and Display Resolutions]].

Mounting the Waveshare LCD Touchscreen can be a challenge! This 3D print design mounts it flat to the panel: https://www.thingiverse.com/thing:1941701
This 3D print design mounts it at an angle: https://www.thingiverse.com/thing:1920486.

Note that, when mounted, none of the touchscreen sensitive areas should be in contact with the surround.

===GPIO Extender Card===

In the completed unit, there are a number of signals that need to be routed in or out of the GPIO interface on the RPi. Plus we need to break out all 40 pins of the GPIO, and have another connector on top for the Waveshare LCD display (if used). Because of this the Portsdown team have designed a PCB for the job - the blank PCB for this is available from the BATC shop.

Buying an extender card early in the project reduces the chance of damage to the RPi and allows these connections to be made safely.

[[File:screw t.jpg|400px]]

The BATC card is very simple to construct with no components other than plugs and sockets.

For full construction details and a list of suppliers for the plugs and sockets see [[GPIO breakout|the GPIO breakout page]]

You can buy the GPIO Extender Card blank PCB from the [https://batc.org.uk/shop/portsdown-transmitter-gpio-breakout-board-blank-pcb/ Portsdown section in the BATC shop - item 3]

===LimeSDR ===

The Portsdown system can use the LimeSDR Mini (or LimeSDR USB) to provide the modulator and RF generator functions.

[[File:LimeMini.jpg|400px]]

[[Using LimeSDR with Portsdown|See this page]] for more details on using the LimeSDR in a Portsdown system.

===Pluto SDR===

The Portsdown 4 uses the Pluto SDR connected via the USB port to provide the modulator and RF generator functions.

See this page for more details: [[Portsdown_4_Pluto]]

----------------------

'''You now have the components for a fully working Portsdown transmitter!

---------------------

'''''However, you will need a camera and audio input to transmit pictures and sound.'''''

===Raspberry Pi Camera===

If you want to transmit live pictures you will need a camera. The standard V1 or V2 Pi camera gives excellent results but will need mounting in a housing and does not have audio input.

Raspberry Pi 2 Camera: CPC Farnell https://cpc.farnell.com/raspberry-pi/rpi-8mp-camera-board/raspberry-pi-camera-board-v2/dp/SC18701

The Portsdown is only compatible with the Raspberry Pi V1, V2 and HQ cameras. '''It will not operate with the V3 camera or the Global Shutter Camera''', as these require a later version of the operating system which does not support the video encoding features used by the Portsdown transmitter. Raspberry Pi Camera information can be found here: https://www.raspberrypi.com/documentation/accessories/camera.html#hardware-specification

===Optional RPi camera Extension Lead Kit===

The RPi camera gives excellent results, but only comes with a short ribbon cable to connect it to the RPi.

It is possible to use some higher quality HDMI leads (the ground connections all need to be made) to extend the camera lead - this does NOT mean the signal out of the camera is HDMI, it is actually "Camera Serial Interface Type 2 (CSI-2)". We are just using HDMI cable as a useful extension lead.

Kits are available to connect a female HDMI connector to the RPi camera connector, and another female to the camera, allowing the use of domestic 1, 2 and 3m HDMI leads.The maker is Petite Studio

RPi Camera HDMI Lead Extension Kit: https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

In the UK and most of the world it's best to get [https://shop.pimoroni.com/products/pi-camera-hdmi-cable-extension?variant=4585578945 the Petite Studio kit at Pimoroni]. It's called Raspberry Pi Camera HDMI Cable Extension.

There are 2 modifications that can be made to enable lower quality HDMI leads (those without all the ground connections made, or even the CEC wire on pin 13 missing) to be used. Full details of these modifications [[CSI-2 to HDMI|are available here.]]

===WebCams===

Some WebCams work with the Portsdown, but it has proved very difficult to support more than a few specific models. The Portsdown 2020 works with the older (pre-2019) versions of the Logitech C920. The Portsdown 4 works with all (3) versions of the C920 and with the Logitech C170. More details on webcams here [[Portsdown Webcams]].

===Composite Video Capture Device===

The transmitter is also capable of working with a USB-connected “EasyCap” dongle to capture PAL composite video from camcorders and analogue mixers etc.

[[File:Fushicai.JPG|200px]]

There are at least 3 similar devices being marketed under this name on eBay, each with different chipsets, but only the Fushicai "USBTV007" brand is guaranteed to work in all modes on the Portsdown 2020 and Portsdown 4. The Portsdown 4 was modified in Oct 2023 to partially support the "MS2106". The type of EasyCap can be identified by connecting it to the Portsdown 4, selecting “Menu 2”, “File Menu”, “List USB Devices”. Then refer to the table below.

{| class="wikitable"
! Name !! USB Ident !! Compatibility !! Notes
|-
| Fushicai || 1b71:3002 Fushicai... || Portsdown 2020 and Portsdown 4 || BATC Shop pre-2020
|-
| MS2106 || 534d:0021 || Limited with Portsdown 4 only || BATC Shop post-2020
|-
| Arkmicro || 18ec:5555 Arkmicro.... || None ||
|}

Latest versions of the Portsdown 4 will work for Lime and Pluto DVB-S/S2 H264 transmission and streaming with the MS2106 EasyCap that is available from the BATC Shop (2023) https://batc.org.uk/shop/video-capture-device-not-for-use-with-portsdown/. The Chipset in this EasyCap is based on the MS2106 chip from MacroSilicon, hence the name.

The MS2106 has some limitations: The lip sync with this EasyCap is not perfect, but it has not proved possible to improve it, and it needs to be driven with a valid composite video signal otherwise the transmitter fails to start.

===Audio Capture Device===

eBay provides a good source for very cheap audio capture USB dongles, which can provide an audio input to go with the RPi camera. The audio capuure device must be of the type shown here:

[[File:04 USB Audio.png|200px]]

Other stand-alone USB audio capture devices may not work and the software will not be changed to support them. Please don't ask.

This type of audio capture device is also compatible with the Ryde DATV Receiver and the Langstone Microwave transceiver. The microphone connection is for a T-R-S 3.5mm jack. Be careful when buying e.g. a Lavellier Tie-pin microphone to avoid those with T-R-R-S lacks. These do not produce any audio in the Portsdown!

-----------------------------
'''That completes the basic Portsdown transmitter shopping list'''

---------------------
'''''However, the team has designed some additional components to enable you to build a complete DATV transmit system'''''

===RF Switching===

The complete RF switching arrangement illustrated below allows you to select the output from the Lime SDR or Pluto, adjust the exact level and then route the RF to any one of 8 PAs or transverters. All the blocks in the diagram are optional; however, you can build a very comprehensive system if you want to. Note that the 4-way decode and switch boards can be substituted for the 8-way decode and switch boards.

[[File:20190511 Portsdown RF Switching.jpg|600px]]

===4-Band RF Output Switch===

The Portsdown team have developed a 4-Band RF output switch capable of switching the low level output of the Lime Mini / Pluto to separate amplifiers for the 70, 144, 437 and 1255 MHz bands. Note: due to potential high insertion loss, it is not recommended to use the switch above 23cms.

[[File:Pd out SW.jpg|300px]]

Full details including parts list and schematic are available [[RF output switch|on this wiki page]].

===4-Band Decode Switch===

The Portsdown provides band switching and PTT outputs on the GPIO pins - these outputs need to be decoded to provide an output for each band.

[[File:Band decoder.JPG|200px]]

The Portsdown team have designed a simple board for switching between 4 bands and buffering the PTT signal which can be either constructed on 0.1” perforated board (veroboard) or on a PCB - this can be home etched.
Full details on the board including circuit etc [[PTT and band switching|are available here.]]
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-transmitter-4-band-decode-blank-pcb/ BATC shop - item 5].

===8-Band RF Output Switch===

For those of you who also want to drive Microwave transverters from your Portsdown, the team have developed an 8-Band RF output switch that includes an RF amplifier. It is designed to be used with the Output Attenuator (see below). It will be capable of amplifying the variable level from the attenuator and switching it to separate amplifiers for the 70, 144, 437 and 1255 MHz bands, and to 4 transverters for the higher bands. PCBs are on order and will be available from the BATC Shop.

Full details including parts list and schematic are available [[8-Band RF Output Switch|on this wiki page]].
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-way-rf-output-switch-blank-pcb/ BATC shop - item 9].

===8-Band Decoder===

This 8-band decoder is designed to work with the 8-band RF output switch and the Portsdown software. It will provide switching signals (either always on, or PTT activated) to 4 Power Amplifiers and 4 transverters, and it also enables you to set which VCO filter should be switched in for the 4 transverter outputs. PCBs are on order and will be available from the BATC Shop.

Full details on the board including circuit etc [[8-Band Decoder|are available here.]]
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-band-decode-blank-pcb/ BATC shop - item 7].

===8-Band Decode PIC===

This is the pre=programmed PIC to control the custom designed 8 band decode board for the Portsdown transmitter.

Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-band-decode-pic/ BATC shop - item 8].

===2-Way RF Switch===

Not required for Portsdown 4.

This switch allows you to route the outputs from the Portsdown 2017 Filter Modulator card and a LimeSDR to a single PA, enabling both to be used without reconfiguration. Full details on this Wiki page [[2-Way RF Switch]].

===Filters and PA drivers===

It is absolutely essential that the Portsdown transmitter output is followed by suitable bandpass filters.
These are not included as part of the project but a [[Filters|number of designs and suppliers are listed here.]]

===Output Attenuator===

Although NOT required when using the Lime Mini or Pluto SDR, the Portsdown can use an electronically switched attenuator to adjust the transmit drive level for each band. Attenuators based on the PE4302, HMC1119 or PE43703 (preferred) are supported.

[[File:PE43073 post-mod small.jpg|400px]]

These attenuators are available on eBay. Full details and wiring instructions are detailed here: [[Output Attenuator]].

Gerber Files

2023-03-31T15:35:30Z

M0YDH: /* G0MJW's HF3 relay board */

Gerber Files

2023-03-31T15:35:00Z

M0YDH: /* G0MJW's HF3 relay board */

Gerber Files

2023-02-28T17:42:49Z

M0YDH: /* M0RNW's G8TA Rx/Tx Changeover Controller Board */

Gerber Files

2023-02-28T17:41:56Z

M0YDH: /* M0RNW's G8TA Rx/Tx Changeover Controller Board */

Gerber Files

2023-02-28T17:41:36Z

M0YDH: /* M0RNW's G8TA Rx/Tx Changeover Controller Board */

Gerber Files

2023-02-28T17:39:18Z

M0YDH: G8TA Rx/Tx Changeover Controller Board

File:RxTxChangeoverV1.ino

2023-02-28T17:29:43Z

M0YDH: Sketch for Nano V3 for G8TA Rx/Tx Changeover controller by Ron M0RNW

== Summary ==
Sketch for Nano V3 for G8TA Rx/Tx Changeover controller by Ron M0RNW

File:G8TA Portsdown RxTx Changeover -1.jpg

2023-02-28T17:23:39Z

M0YDH: Assembled changeover controller

== Summary ==
Assembled changeover controller

File:RxTx-Changeover.pdf revised 20230207.pdf

2023-02-27T21:29:35Z

M0YDH: M0RNW changeover controller schematic CQ-TV 279

== Summary ==
M0RNW changeover controller schematic CQ-TV 279

File:Rx-Tx Changeover Gerbers.zip

2023-02-27T21:27:25Z

M0YDH: Gerbers for the M0RNW Rx-Tx changeover controller in CQ-TV 279

== Summary ==
Gerbers for the M0RNW Rx-Tx changeover controller in CQ-TV 279

Gerber Files

2023-02-27T21:23:18Z

M0YDH: /* G0MJW's HF3 relay board */

Gerber Files

2023-02-27T21:22:58Z

M0YDH: HF3 relay board #2

File:HF3 relay board gerbers.zip

2023-02-27T21:20:48Z

M0YDH: Gerbers for SPDT relay PCB by G0MJW

== Summary ==
Gerbers for SPDT relay PCB by G0MJW

File:HF3 Relay board.JPG

2023-02-27T21:18:14Z

M0YDH: KiCAD image of G0MJW design PCB

== Summary ==
KiCAD image of G0MJW design PCB

Gerber Files

2023-02-27T21:17:05Z

M0YDH: HF3 relay board #1

51 MHz

2023-02-24T18:33:32Z

M0YDH: /* 51 MHz DATV Introduction */

==51 MHz DATV Introduction==

from [https://forum.batc.org.uk/viewtopic.php?f=15&t=7847 50 MHz - a reminder - Forum post ]

The bandplan recommends 51.7 MHz. Probably best to start with 333 kHz DVB-T, QPSK, Guard 1/32, FEC 2/3.

For receive, you can tune there directly with a Knucker tuner and a Portsdown or Ryde. I would suggest a band-pass filter and a preamp (in that order).

For transmit, you can use a Portsdown 4 with LimeSDR, which will give you +1 dBm on 51.7 Mhz with a Lime Gain of 92. Or you can use a Portsdown 4 with a Pluto, which will give you -10 dBm at 0 Pluto Power (the maximum).

Dave, G8GKQ

Receive upconverter detailed on [[71_MHz|71_MHz Wiki page]] will also make a 451.7 MHz signal if DVB-S or S2 is being fed into a Minitiouner.

The Mini-Circuits RBP-75 band pass filter will pass 51.7MHz. Other low power filters are to be found on the QRP-Labs shop pages for under £5 each

In the [[70MHz_filters|70MHz Filters section of this Wiki]] G4GUO's low pass filter from CQ-TV-260 intended for 71MHz duty will do also well for 51.7MHz. Note flat top response 50 Hz [spike on left of spectrum] to 75 MHz

A cheap, lightweight antenna for your initial tests is [https://sites.google.com/site/gw7aav2/50mhzdeltaloop Steve GW&AAV's delta loop] Also a combined pair of these antennas are shown on his 4m page.

51 MHz

2023-02-24T18:31:48Z

M0YDH:

==51 MHz DATV Introduction==

from [https://forum.batc.org.uk/viewtopic.php?f=15&t=7847 50 MHz - a reminder - Forum post ]

The bandplan recommends 51.7 MHz. Probably best to start with 333 kHz DVB-T, QPSK, Guard 1/32, FEC 2/3.

For receive, you can tune there directly with a Knucker tuner and a Portsdown or Ryde. I would suggest a band-pass filter and a preamp (in that order).

For transmit, you can use a Portsdown 4 with LimeSDR, which will give you +1 dBm on 51.7 Mhz with a Lime Gain of 92. Or you can use a Portsdown 4 with a Pluto, which will give you -10 dBm at 0 Pluto Power (the maximum).

Dave, G8GKQ

Receive upconverter detailed on [[71_MHz|71_MHz Wiki page]] will also make a 451.7 MHz signal if DVB-S or S2 is being fed into a Minitiouner.

The Mini-Circuits RBP-75 band pass filter will pass 51.7MHz. Other low power filters are to be found on the QRP-Labs shop pages for under £5 each

In the [[70MHz_filters|70MHz Filters section of this Wiki]] G4GUO's low pass filter from CQ-TV-260 intended for 71MHz duty will do also well for 51.7MHz.

A cheap, lightweight antenna for your initial tests is [https://sites.google.com/site/gw7aav2/50mhzdeltaloop Steve GW&AAV's delta loop] Also a combined pair of these antennas are shown on his 4m page.

51 MHz

2023-02-24T18:28:50Z

M0YDH: low pass filter

51 MHz DATV
from [https://forum.batc.org.uk/viewtopic.php?f=15&t=7847 50 MHz - a reminder - Forum post ]

The bandplan recommends 51.7 MHz. Probably best to start with 333 kHz DVB-T, QPSK, Guard 1/32, FEC 2/3.

For receive, you can tune there directly with a Knucker tuner and a Portsdown or Ryde. I would suggest a band-pass filter and a preamp (in that order).

For transmit, you can use a Portsdown 4 with LimeSDR, which will give you +1 dBm on 51.7 Mhz with a Lime Gain of 92. Or you can use a Portsdown 4 with a Pluto, which will give you -10 dBm at 0 Pluto Power (the maximum).

Dave, G8GKQ

Receive upconverter detailed on [[71_MHz|71_MHz Wiki page]] will also make a 451.7 MHz signal if DVB-S or S2 is being fed into a Minitiouner.

The Mini-Circuits RBP-75 band pass filter will pass 51.7MHz. Other low power filters are to be found on the QRP-Labs shop pages for under £5 each

In the [[70MHz_filters|70MHz Filters section of this Wiki]] G4GUO's low pass filter from CQ-TV-260 intended for 71MHz duty will do also well for 51.7MHz.

A cheap, lightweight antenna for your initial tests is [https://sites.google.com/site/gw7aav2/50mhzdeltaloop Steve GW&AAV's delta loop] Also a combined pair of these antennas are shown on his 4m page.

51 MHz

2023-02-24T18:19:29Z

M0YDH: Initial details

51 MHz DATV
from [https://forum.batc.org.uk/viewtopic.php?f=15&t=7847 50 MHz - a reminder - Forum post ]

The bandplan recommends 51.7 MHz. Probably best to start with 333 kHz DVB-T, QPSK, Guard 1/32, FEC 2/3.

For receive, you can tune there directly with a Knucker tuner and a Portsdown or Ryde. I would suggest a band-pass filter and a preamp (in that order).

For transmit, you can use a Portsdown 4 with LimeSDR, which will give you +1 dBm on 51.7 Mhz with a Lime Gain of 92. Or you can use a Portsdown 4 with a Pluto, which will give you -10 dBm at 0 Pluto Power (the maximum).

Dave, G8GKQ

Receive upconverter detailed on [[71_MHz|71_MHz Wiki page]] will also make a 451.7 MHz signal if DVB-S or S2 is being fed into a Minitiouner.

The Mini-Circuits RBP-75 band pass filter will pass 51.7MHz. Other low power filters are to be found on the QRP-Labs shop pages for under £5 each

A cheap, lightweight antenna for your initial tests is [https://sites.google.com/site/gw7aav2/50mhzdeltaloop Steve GW&AAV's delta loop] Also a combined pair of these antennas are shown on his 4m page.

BATC Wiki

2023-02-24T18:08:24Z

M0YDH: /* The ATV bands */ 6m page link added

'''Welcome to the British Amateur Television Club Wiki''' - the place to find information on all Amateur Television related equipment and projects. For details on how to join the BATC, the member's shop and CQ-TV archive and download visit the BATC website https://batc.org.uk/

This is your site, developed by the BATC for use by the worldwide ATV community - any information which you feel is of use to others can be put on the Wiki but please observe any copyright restrictions on the material you use.

* New to Amateur TV - Get the basics on our [[Getting Started|Getting Started page]]

* For details on the Portsdown DATV transmit and receive system go to [[The Portsdown DATV transceiver system|the Portsdown pages]]

* For information on the MiniTiouner USB DATV receiver go to [[MiniTioune|MiniTiouner]]

* For the DATV equipment capability list go to [[DATV equipment capability|https://wiki.batc.org.uk/DATV_equipment_capability]]

== Contents ==
* [[Registering]] on the BATC wiki

== New to Amateur TV? ==
* Get the basics on our [[Getting Started|Getting Started page]]

==BATC Information and services==
* [[Joining the BATC]]

* [[Renewing your membership]]

* The [[BATC Privacy statement and data protection policy]]

* The [[BATC forum]]

* The [[BATC shop]]

* The [[The_new_streamer|BATC streamer]]

* The [[BATC archive]] Collection of photos and documents from BATC's past

* The [[new BATC website|BATC website]]

== BATC projects ==
* [[The Portsdown Transmitter]] - the BATC's Raspberry Pi-based DATV Transmitter
* [[MiniTioune]] - the DATV DVB-S / S2 receiver project
* [[Ryde Receiver]] - Dedicated DATV set top box project
* [[Knucker]] - Variable bandwidth DVB-T project
* [[Advanced receiver hardware]] - Details of the BATC advanced receiver hardware.
* [[WinterHill Receiver Project]] - Multi-channel DVB-S / S2 project
* [[BATC Video Source]] - The Raspberry Pi-based composite video source described in CQ-TV 270
* [[Digilite]] - The original home build DATV construction project
* [[Repeater Controller]] - The BATC ATV Repeater Controller using a Raspberry Pi 4

== CQ-TV Magazine ==
* [[Index of articles]]
* [[Archive edition|Archive editions]] download
* [[BATC_Software_Library]] for project downloads

==BATC Event Streaming Equipment==
* [[Equipment Description]]

== BATC Conventions ==
* [[CAT 22 part 2]] Presentations from the CAT 22 Part 2 Zoom Meeting.
* [[CAT 22 part 1]] Chairman's report from the BATC GM
* [[CAT 21]] Presentations from CAT 21 which was conducted as a Zoom Meeting.
* [[CAT 20]] Presentations from CAT 20 which was conducted as a Zoom Webinar.
* [[CAT 19 South|CAT 19 South (Didcot)]] Presentations from the 2019 regional convention at Didcot.
* [[CAT 19 Finningley]] Presentations from the 2019 regional convention at Finningley.
* [[CAT 19 Bristol]] Presentations from the 2019 regional convention at Bristol.
* [[CAT 18|CAT 18 Coventry]] Presentations and links to the videos from the 2018 convention.
* [[CAT 17|CAT 17 Finningley|]] Antenna test range results, presentations and links to the videos from the 2017 convention.
* [[Presentations from CAT 16|CAT 16 Cosford]] Presentations and links to the videos from the 2016 convention.
* Video Recordings from previous ATV Conventions can be found on the [https://www.youtube.com/channel/UCUWLnUZllytlcCFd93tnBzw BATC YouTube Channel].

==National and International Events==

* [[ HAM RADIO 2018 ]] ATV Presentations from HAM RADIO 2018 at Friedrichsafen.

* [[ HAM RADIO 2019 ]] ATV Presentations from HAM RADIO 2019 at Friedrichsafen.

* [[ HAM RADIO 2022 ]] ATV Presentations from HAM RADIO 2022 at Friedrichsafen.

* [[ RSGB Convention 2022 ]] ATV Presentation at the 2022 RSGB Convention 2022

== Getting on the air with ATV ==
===The ATV bands===
* [[29 MHz]]
* [[51 MHz]]
* [[71 MHz]]
* [[146 MHz RB-TV]]
* [[70cms Analogue TV]]
* [[70cm DATV]]
* [[23cms ATV]]
* [[13cms]]
* [[3.4 GHz DATV]]
* [[5.6 GHz]]
* [[10 GHz]]
* [[:Media:ATV on 5.6 10 and 24 Ghz.pdf|April 2018 Presentation to MMRT about ATV on 5.6 10 and 24 GHz]]

===The different ATV modes===
* [[Reduced bandwidth TV]] (RB-TV)
* [[The Effect of FEC]]

===Equipment Options===
* [[DATV transmitting Equipment]]

==Advanced encoding / input options==

Details of advanced transmission configurations, primarily for H265,and video production software.

* [[Feeding Video to Portsdown from vMix|Vmix output in to Portsdown IPTS input]]
* [[OBS - Open Broadcast Studio|OBS output in to Portsdown IPTS input]]
* [[Using GTX10xx Graphics card encoder with OBS]]
* [[Custom_DATV_Firmware_for_the_Pluto|Using the Pluto for DATV]]
* [[Jetson_Nano|Using the Jetson Nano with Portsdown]]

== Operating ==
* [[DATV equipment capability]] - Wiki page documenting the capabilities of common DATV transmit and receive equipment.
* [[ATV standards]] - a list of standards used by ATV operators including FM bandwidths, DATV PIDs, symbol rates and FEC
* [[EMF Compliance]] - information about EMF compliance for ATV and Microwave Operation
* [[Directory of portable sites]] suitable for ATV and microwave operation
* [https://www.google.com/maps/d/u/0/edit?mid=1VeLnRRbLwloDTL2i9-HE2sxqL0c&ll=52.95536632179757%2C-0.49709419999999227&z=7 Google map] showing possible portable operating sites
* [[Mapping tools]] including finding the QRA locator of a site, UK postcode to Lat and Long conversion and a topographic overlay for Google maps
* [[Propagation tools]]
* [[UK ATV DX Records]] - a list of Known DX Records for the UK
* [[2022 Activity Weekends]]
* [[2023 BATC Activity Weekends & Contests]]
* [[Christmas 2022 Repeater Contest & Activity Challenge]]
* [[2021 5.6GHz Activity Ladder]]
* [[IARU ATV contest]] - How to enter the annual international TV contest
* [[IARU ATV contest 2022 International Results]] - International Results for the June 2022 IARU Contest
* [[IARU ATV contest 2021 International Results]] - International Results for the June 2021 IARU Contest
* [[IARU ATV contest 2020 International Results]] - International Results for the June 2020 IARU Contest
* [[IARU ATV contest 2019 International Results]] - International Results for the June 2019 IARU Contest
* [[IARU ATV contest 2018 Results]] - UK Results for the June 2018 IARU and BATC Contests
* [[IARU ATV contest 2018 International Results]] - International Results for the June 2018 IARU Contest
* [[September 2019 BATC Low Band Contest]]

==ATV repeaters==
* [[UK ATV repeaters]]
* [[USA ATV repeaters]]
* [[Australian TV repeaters]]

* [[Technical topics for ATV repeater builders]]

==Es'hail-2==
* [[Es'hail-2 Basic Information|Getting started, LNBs and aligning a dish]]

* [[Es'hail-2 Ground Station|Es'hail-2 BATC WebSDR & DATV Spectrum Monitor]]

* [[Es'hail-2 DATV Bandplan]]

* [[Es'hail-2_LNBs_and_Antennaes|Es'hail-2_LNBs]]

* [[Transmitting_Oscar_100_DATV_signals|Es'hail-2 Transmitters]]

* [[Es'hail-2 Antennaes]]

* [[Es'hail-2 conference transmissions]]

==ATV projects==
* [[Adalm Pluto]] - Collection of information on using the Adalm Pluto for DATV
* [[The MacGuffin Project]] - Collection of tools used to create an automated multi-band ATV system
* [[Receiver upconverters]] - Details of upconverters to receive 146 and 437 MHz on STB and MiniTioune
* [[Jetson Nano]] - Third generation computer-based DATV Transmitter
* [[DTX1 TS]] - interface board to take in TS streams to the DTX1
* [[RpiDATV]] - software for the Rpi
* [[RBTVMOD]] - variable rate RB-TV mdulator for the Rpi
* [[DATVExpress]] - SDR hardware based DATV transmitter covering 70 - 2450 MHz
* [[PE4302]] - PE4302 variable attenuator project
* [[ADF435x PIC]] - PIC controllers for Chinese ADF4350/4351 boards
* [[DigiTwist]] - an experimental 2 axis satellite tracker
* [[G4WIM PA controller]] - an advanced PA controller design by G4WIM published in CQ-TV 265
* [[WinterHill Receiver Project]]
* [[Tilt-O-Matic]] Pan and tilt head for surveyor tripods
* [[Gerber Files]] Index of Gerber (PCB) files used by BATC and Memnbers' Projects

== Deutschsprachiges Wiki ==

* Portsdown DATV Projekt - Deutschsprachiges Wiki
* Minitioune(r) - Deutschsprachiges Wiki

== Useful Circuits and notes ==
* [[Antenna changeover relays]] - Notes on suitable antenna change over relays for ATV use.
* [[Filters]] - Collection of links and designs for that most critical but over looked component!
* [[Pre-amps]] - Notes, suppliers and circuits of pre-amplifiers suitable for ATV
* [[Power amplifiers]] - Notes, suppliers and circuits of power amplifiers suitable for ATV
* [[Video circuits]] - Notes and circuits for video processing
* [[Satellite receiver tuning offsets]] - Note on how to set up a satellite receiver to directly receive L band signals.
* [[Using ex-satellite dishes]] - Notes on how to find the feed point of a dish and designs for feeds to use

== ATV Equipment manuals and schematics ==
* [[Bob Platts G8OZP]] Circuits and documentation for the Bob Platts range of equipment
* [[Comtech module]] - 23cms and 13cms ATV Tx and Rx circuits and guides
* [[Solent ATV units]] - Tx and Rx circuits and information
* [[Wood & Douglas FM TV equipment]] - Circuits, pcb layouts and information
* [[LMW Electronics]] - Circuits, pcb layouts and information
* [[Fortop]] - Circuits, pcb layouts and information
* [[Glencom]] - VC-510 VHF to L band up converter circuit diagram and modifications
* [[Global communications]] - Hand drawn circuit of tuneable 70 / 140 MHz to L band block up converter
* [[Jaybeam]] - Details of many Jaybeam aerials

== Ex commercial broadcast equipment manuals ==
* [[NDS System 3000]]
* [[NDS Alteia rx]]

== Test equipment manuals ==
For HP and Agilent equipment see the [https://groups.yahoo.com/neo/groups/hp_agilent_equipment/info Yahoo group]

== Other equipment information related to ATV ==

29MHz transverter

2023-01-30T17:00:12Z

M0YDH: /* PCBs */ tense change

The popular SDRs that are used to transmit DATV at higher frequencies are the Adlam-pluto and Lime Mini. The pluto does not work below 70MHz and while the Lime Mini does cover 29MHz natively, in practice the spectrum it generates in this region is not sufficiently clean to use on the air. To get round these issues, Mike G0MJW has designed a simple 149 to 29MHz transverter. It is designed to fit into a standard Hammond 1590B 'stompbox' die-cast box.

[[File:29MHz transverter 2.JPG|400px]]

[[File:29MHz transverter 1.JPG|400px]]

=Building the transverter=

==PCBs==

PCBs is stocked in the BATC shop.

The gerber files are available here: [[:File:DVBT_Transverter_rev5.zip]]

==BOM and schematics==

The BOM version by G4KLB is available for download: [[:File:Transverter BOM.xlsx]]

The schematics are available here:[[:Media:DVBT_Transverter.pdf]]

5 crystal oscillators are available here for about £13 delivered.
https://www.ebay.co.uk/itm/202891111938

29MHz transverter

2023-01-30T16:58:23Z

M0YDH: 1590B box

The popular SDRs that are used to transmit DATV at higher frequencies are the Adlam-pluto and Lime Mini. The pluto does not work below 70MHz and while the Lime Mini does cover 29MHz natively, in practice the spectrum it generates in this region is not sufficiently clean to use on the air. To get round these issues, Mike G0MJW has designed a simple 149 to 29MHz transverter. It is designed to fit into a standard Hammond 1590B 'stompbox' die-cast box.

[[File:29MHz transverter 2.JPG|400px]]

[[File:29MHz transverter 1.JPG|400px]]

=Building the transverter=

==PCBs==

PCBs will be stocked in the BATC shop.

The gerber files are available here: [[:File:DVBT_Transverter_rev5.zip]]

==BOM and schematics==

The BOM version by G4KLB is available for download: [[:File:Transverter BOM.xlsx]]

The schematics are available here:[[:Media:DVBT_Transverter.pdf]]

5 crystal oscillators are available here for about £13 delivered.
https://www.ebay.co.uk/itm/202891111938

29MHz transverter

2023-01-19T21:47:45Z

M0YDH: /* BOM and schematics */ tcxo on EBay

The popular SDRs that are used to transmit DATV at higher frequencies are the Adlam-pluto and Lime Mini. The pluto does not work below 70MHz and while the Lime Mini does cover 29MHz natively, in practice the spectrum it generates in this region is not sufficiently clean to use on the air. To get round these issues, Mike G0MJW has designed a simple 149 to 29MHz transverter. It is designed to fit into a standard Hammond 1590 series 'stompbox' die-cast box.

[[File:29MHz transverter 2.JPG|400px]]

[[File:29MHz transverter 1.JPG|400px]]

=Building the transverter=

==PCBs==

PCBs will be stocked in the BATC shop.

The gerber files are available here: [[:File:DVBT_Transverter_rev5.zip]]

==BOM and schematics==

The BOM version by G4KLB is available for download: [[:File:Transverter BOM.xlsx]]

The schematics are available here:[[:Media:DVBT_Transverter.pdf]]

5 crystal oscillators are available here for about £13 delivered.
https://www.ebay.co.uk/itm/202891111938

29MHz transverter

2023-01-19T21:41:22Z

M0YDH: die cast box

The popular SDRs that are used to transmit DATV at higher frequencies are the Adlam-pluto and Lime Mini. The pluto does not work below 70MHz and while the Lime Mini does cover 29MHz natively, in practice the spectrum it generates in this region is not sufficiently clean to use on the air. To get round these issues, Mike G0MJW has designed a simple 149 to 29MHz transverter. It is designed to fit into a standard Hammond 1590 series 'stompbox' die-cast box.

[[File:29MHz transverter 2.JPG|400px]]

[[File:29MHz transverter 1.JPG|400px]]

=Building the transverter=

==PCBs==

PCBs will be stocked in the BATC shop.

The gerber files are available here: [[:File:DVBT_Transverter_rev5.zip]]

==BOM and schematics==

The BOM version by G4KLB is available for download: [[:File:Transverter BOM.xlsx]]

The schematics are available here:[[:Media:DVBT_Transverter.pdf]]

Assembling Portsdown

2022-12-08T19:58:53Z

M0YDH: /* Mechanical Design */

This section will describe in detail how to assemble your Portsdown transmitter - to begin, you need to have bought or built all the components listed in the [[Portsdown hardware|hardware description.]]

This page describes how to build the complete transmitter assembly but you can run the Portsdown as an experiment in [[QPSKRF or Ugly mode|"Ugly Mode"]], currently labelled in the Menu as QPSKRF. That does not require you to wire anything together.

===Mechanical Design===

First of all, decide on your mechanical design. You are going to need to have the RPi firmly mounted, with the Micro-SD card slot accessible (to change the card if required) and the power, network and USB connectors available. Then you will need to stack a GPIO extender on top of the RPi. A secondhand 3U 19" rack case with mounting rails for vertical circuit cards may well be a good value purchase that is tall enough to take the 7 inch screen if you upgrade to Portsdown 2020 [Portsdown 3] later on. There will be enough room in this for a Minitioune receiver, 71MHz upconverter, all of the Portsdown 2018 hardware, a Lime Mini SDR, voltage converters and maybe some switch gear for amps.

A front panel as CAD models for a 19 inch 3U box is here [[File:Portsdown_3_Front_Panel.zip]] in .dxf and .stp formats within a zip archive. The dxf could be printed full size and used as a cutting template.

The most difficult part will be to mount the Touchscreen display. It can either be stacked on top of the RPi, or you can connect it by a short multiway lead and mount it on the front panel of your housing - an example is here: http://www.ebay.co.uk/itm/141354697688.

If you have a 3D printer you could try make up one of these housing http://www.thingiverse.com/thing:1920486 . You will need a carved wooden packing piece between the back of the screen and the box front panel to support it.

The Waveshare 3.5" touchscreens always seemed to fail during unit construction. If you must use one ask another member for a dead one to use as a template. Then fit your working one at the last minute into its bezel. The official RPi 7 inch touch screen is far superior and mounts well in a 3d printed bezel from a design available from G4XAT.

You will then need to consider mounting the ADF4351 Synthesizer, any LO filters and then the Filter/modulator board. Other things to think about might be a 5V power supply, a relay/PTT switching board and any dongles (EasyCap, Sound or RTL-SDR).

The block diagram of what you are trying to achieve is below. Note that you will need an additional filter between the synthesizer and the filter/modulator board for 437 MHz and 146 MHz. It is not required for 1255 MHz, and the unit will work on the other bands for testing without it.

[[File:1-1 Block Diagram.jpg|600px]]

An example layout is here

[[File:In the box.jpg|600px]]

All the circuit cards for Portsdown 2018 except band decode and GPIO Breakout can be mounted on M3 stand-offs on both sides of a rectangle of plain PCB. A housing for a 25 way D connector can be constructed and soldered on. This has sufficient connections to take all the wiring across to the GPIO Breakout. RG402 semi-rigid coax and SMA fittings have been used with Molex KK connectors for the wiring. Pictures are from M0YDH.

[[File:P2020 M0YDH 03.jpg|600px]] [[File:P2020 M0YDH 04.jpg|600px]]

Here are the Portsdown 2018 cards in a Portsdown 2020 and next to the Pi3 - all in a 3U 19 inch rack case.

[[File:P2020 M0YDH 02.jpg|600px]] [[File:P2020 M0YDH 01.jpg|600px]]

===Interconnecting the modules===

The following diagram shows the interconnects between the various modules - all wire can be non screened (except the Local oscillator feed to the Filter modulator board) but should be kept as short as possible.

[[File:Portsdown interconnects.JPG|600px]]

Higher resolution pdf is available here [[:File:Portsdwon interconnect v2.pdf]]

Or a picture might help...

[[File:assembly.JPG|600px]]

===BATC GPIO breakout card===

The GPIO breakout card is where all the signals and power for Portsdown interconnect and we recommend that you buy the blank PCB from the BATC and make up the breakcard using either connectors or hard wiring to the other boards.
For more details see this [[GPIO breakout|wiki page]]

[[File:screw t.jpg|300px]]

[[Willow components breakout card]] (If you have bought the BATC GPIO breakout card you DO NOT NEED to read this section)

===Powering the ADF4351===

The ADF4351 module needs between 5 and 9 volts on its power connector. You can either buy a suitable (small barrel) connector or solder the wires to the underside of the board. The 5V supply can be taken from the same source as the Raspberry Pi 5.2V supply, or from any other 5V supply. It does not need to be very clean. DO NOT try to put 3.3V into the marked pin on the data connector on the module; this is a low current output, not an input.

===RF Wiring===

Use short flexible SMA cables to connect the ADF4351 (through filters if necessary) to the filter/modulator board. Use another cable to take the output to a panel connector or subsequent filters and power amplifiers.

You may also want to extend the input of any RTL-SDR to be accessible from a panel connector.

===Power Supplies and Wiring===

You should power the RPi through the Micro-USB power connector to take advantage of the input protection provided. Use a very short USB cable to your power supply as most of these cables are of very poor quality and cause significant voltage drop. For best results, cut the USB cable 5cm from the connector and run "real" wiring from there to your power supply.

Do not power unnecessary items from the RPi's 5v outputs on the GPIO connector. Doing so will induce extra voltage drop in the input protection circuitry. Power the VCO filter and RF Switch directly from the switch mode power supply. No problems with ripple have been observed.

A lot of strange problems, such as the Portsdown running very slowly, can be caused by low PSU voltage - the RPi3 supply voltage is actually specified as 5.1 volts, so make sure your PSU delivers enough voltage and is capable of sourcing enough current. See [https://forum.batc.org.uk/viewtopic.php?t=4856&p=11935#p11935 this post on the BATC forum] for a real user experience!

If you see a "Lightning Flash" symbol at the top right of your LCD display it means that the voltage at the RPi is too low. You can measure the voltage between the GPIO connector pins 4 and 6.

[[File:flash.jpg|400px]]

You can check if there are any problems by running the command
vcgencmd get_throttled
from the command line. You should get the response "throttled=0x0" which means that all is well. The response "throttled=0x50000" means that the voltage has dropped below the safe level at least once since boot-up; the response "throttled=0x50005" means that the voltage is currently below the safe level. Other responses might mean that your RPi is overheating. The "Info" screen on Menu 3 will also state if there have been any low-voltage events since boot-up.

An eBay buck regulator capable of supplying at least 4A continuous at 5.2V is recommended to power the RPi, an EasyCap, an RTL-SDR and the ADF4351. '''Consumer-grade RPi power supplies with consumer grade USB cables have rarely proved to be capable of supplying this high demand without causing dropouts.'''

The filter/modulator board needs a clean 5V at 250 mA and the on-board linear regulator supplies this, but can get warm at higher input voltages. The linear regulator needs at least 7V to operate properly. Feeding it with 8 volts provides the best compromise between regulator margin and heat dissipation.

You can use a switching or buck converter to supply the filter-modulator board with 5V, but the switching ripple introduces some detectable sidebands on the transmitted signal. These have very little adverse effect, but are visible on a spectrum analyser. On-board switching regulators have been tested, and the pads are there for L10 to provide extra filtering. Again, they introduce low-level sidebands, but these are probably not significant.

===Network and USB Wiring===

Consider bringing the network connector and one of the USB connectors out to the panel for easy access and mechanical stability.

===Camera Wiring===

The RPi camera gives excellent results, but only comes with a short ribbon cable to connect it to the RPi.

It is possible to use some higher quality HDMI leads (the ground connections all need to be made) to extend the camera lead - this does NOT mean the signal out of the camera is HDMI, it is actually "Camera Serial Interface Type 2 (CSI-2)". We are just using HDMI cable as a useful extension lead. The modification described here https://wiki.batc.org.uk/CSI-2_to_HDMI allows the use of lower quality HDMI cables.

Kits are available to connect a female HDMI connector to the RPi camera connector, and another female to the camera, allowing the use of domestic 1, 2 and 3m HDMI leads. The Pi camera HDMI Lead Extension Kit is available from here https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

===USB Cables===

Use short (shortened?) good quality USB cables to connect the EasyCap and RTL-SDR to the RPi. Use of the poor-quality USB cable supplied with the EasyCap has been shown to cause audio dropouts in a streamed signal.

Assembling Portsdown

2022-12-08T19:56:00Z

M0YDH: /* Mechanical Design */

This section will describe in detail how to assemble your Portsdown transmitter - to begin, you need to have bought or built all the components listed in the [[Portsdown hardware|hardware description.]]

This page describes how to build the complete transmitter assembly but you can run the Portsdown as an experiment in [[QPSKRF or Ugly mode|"Ugly Mode"]], currently labelled in the Menu as QPSKRF. That does not require you to wire anything together.

===Mechanical Design===

First of all, decide on your mechanical design. You are going to need to have the RPi firmly mounted, with the Micro-SD card slot accessible (to change the card if required) and the power, network and USB connectors available. Then you will need to stack a GPIO extender on top of the RPi. A secondhand 3U 19" rack case with mounting rails for vertical circuit cards may well be a good value purchase that is tall enough to take the 7 inch screen if you upgrade to Portsdown 2020 [Portsdown 3] later on. There will be enough room in this for a Minitioune receiver, 71MHz upconverter, all of the Portsdown 2018 hardware, a Lime Mini SDR, voltage converters and maybe some switch gear for amps.

A front panel as CAD models for a 19 inch 3U box is here [[File:Portsdown_3_Front_Panel.zip]] in .dxf and .stp formats within a zip archive. The dxf could be printed full size and used as a cutting template.

The most difficult part will be to mount the Touchscreen display. It can either be stacked on top of the RPi, or you can connect it by a short multiway lead and mount it on the front panel of your housing - an example is here: http://www.ebay.co.uk/itm/141354697688.

If you have a 3D printer you could try make up one of these housing http://www.thingiverse.com/thing:1920486

The Waveshare 3.5" touchscreens always seemed to fail during unit construction. If you must use one ask another member for a dead one to use as a template. Then fit your working one at the last minute into its bezel. The official RPi 7 inch touch screen is far superior and mounts well in a 3d printed bezel from a design available from G4XAT.

You will then need to consider mounting the ADF4351 Synthesizer, any LO filters and then the Filter/modulator board. Other things to think about might be a 5V power supply, a relay/PTT switching board and any dongles (EasyCap, Sound or RTL-SDR).

The block diagram of what you are trying to achieve is below. Note that you will need an additional filter between the synthesizer and the filter/modulator board for 437 MHz and 146 MHz. It is not required for 1255 MHz, and the unit will work on the other bands for testing without it.

[[File:1-1 Block Diagram.jpg|600px]]

An example layout is here

[[File:In the box.jpg|600px]]

All the circuit cards for Portsdown 2018 except band decode and GPIO Breakout can be mounted on M3 stand-offs on both sides of a rectangle of plain PCB. A housing for a 25 way D connector can be constructed and soldered on. This has sufficient connections to take all the wiring across to the GPIO Breakout. RG402 semi-rigid coax and SMA fittings have been used with Molex KK connectors for the wiring. Pictures are from M0YDH.

[[File:P2020 M0YDH 03.jpg|600px]] [[File:P2020 M0YDH 04.jpg|600px]]

Here are the Portsdown 2018 cards in a Portsdown 2020 and next to the Pi3 - all in a 3U 19 inch rack case.

[[File:P2020 M0YDH 02.jpg|600px]] [[File:P2020 M0YDH 01.jpg|600px]]

===Interconnecting the modules===

The following diagram shows the interconnects between the various modules - all wire can be non screened (except the Local oscillator feed to the Filter modulator board) but should be kept as short as possible.

[[File:Portsdown interconnects.JPG|600px]]

Higher resolution pdf is available here [[:File:Portsdwon interconnect v2.pdf]]

Or a picture might help...

[[File:assembly.JPG|600px]]

===BATC GPIO breakout card===

The GPIO breakout card is where all the signals and power for Portsdown interconnect and we recommend that you buy the blank PCB from the BATC and make up the breakcard using either connectors or hard wiring to the other boards.
For more details see this [[GPIO breakout|wiki page]]

[[File:screw t.jpg|300px]]

[[Willow components breakout card]] (If you have bought the BATC GPIO breakout card you DO NOT NEED to read this section)

===Powering the ADF4351===

The ADF4351 module needs between 5 and 9 volts on its power connector. You can either buy a suitable (small barrel) connector or solder the wires to the underside of the board. The 5V supply can be taken from the same source as the Raspberry Pi 5.2V supply, or from any other 5V supply. It does not need to be very clean. DO NOT try to put 3.3V into the marked pin on the data connector on the module; this is a low current output, not an input.

===RF Wiring===

Use short flexible SMA cables to connect the ADF4351 (through filters if necessary) to the filter/modulator board. Use another cable to take the output to a panel connector or subsequent filters and power amplifiers.

You may also want to extend the input of any RTL-SDR to be accessible from a panel connector.

===Power Supplies and Wiring===

You should power the RPi through the Micro-USB power connector to take advantage of the input protection provided. Use a very short USB cable to your power supply as most of these cables are of very poor quality and cause significant voltage drop. For best results, cut the USB cable 5cm from the connector and run "real" wiring from there to your power supply.

Do not power unnecessary items from the RPi's 5v outputs on the GPIO connector. Doing so will induce extra voltage drop in the input protection circuitry. Power the VCO filter and RF Switch directly from the switch mode power supply. No problems with ripple have been observed.

A lot of strange problems, such as the Portsdown running very slowly, can be caused by low PSU voltage - the RPi3 supply voltage is actually specified as 5.1 volts, so make sure your PSU delivers enough voltage and is capable of sourcing enough current. See [https://forum.batc.org.uk/viewtopic.php?t=4856&p=11935#p11935 this post on the BATC forum] for a real user experience!

If you see a "Lightning Flash" symbol at the top right of your LCD display it means that the voltage at the RPi is too low. You can measure the voltage between the GPIO connector pins 4 and 6.

[[File:flash.jpg|400px]]

You can check if there are any problems by running the command
vcgencmd get_throttled
from the command line. You should get the response "throttled=0x0" which means that all is well. The response "throttled=0x50000" means that the voltage has dropped below the safe level at least once since boot-up; the response "throttled=0x50005" means that the voltage is currently below the safe level. Other responses might mean that your RPi is overheating. The "Info" screen on Menu 3 will also state if there have been any low-voltage events since boot-up.

An eBay buck regulator capable of supplying at least 4A continuous at 5.2V is recommended to power the RPi, an EasyCap, an RTL-SDR and the ADF4351. '''Consumer-grade RPi power supplies with consumer grade USB cables have rarely proved to be capable of supplying this high demand without causing dropouts.'''

The filter/modulator board needs a clean 5V at 250 mA and the on-board linear regulator supplies this, but can get warm at higher input voltages. The linear regulator needs at least 7V to operate properly. Feeding it with 8 volts provides the best compromise between regulator margin and heat dissipation.

You can use a switching or buck converter to supply the filter-modulator board with 5V, but the switching ripple introduces some detectable sidebands on the transmitted signal. These have very little adverse effect, but are visible on a spectrum analyser. On-board switching regulators have been tested, and the pads are there for L10 to provide extra filtering. Again, they introduce low-level sidebands, but these are probably not significant.

===Network and USB Wiring===

Consider bringing the network connector and one of the USB connectors out to the panel for easy access and mechanical stability.

===Camera Wiring===

The RPi camera gives excellent results, but only comes with a short ribbon cable to connect it to the RPi.

It is possible to use some higher quality HDMI leads (the ground connections all need to be made) to extend the camera lead - this does NOT mean the signal out of the camera is HDMI, it is actually "Camera Serial Interface Type 2 (CSI-2)". We are just using HDMI cable as a useful extension lead. The modification described here https://wiki.batc.org.uk/CSI-2_to_HDMI allows the use of lower quality HDMI cables.

Kits are available to connect a female HDMI connector to the RPi camera connector, and another female to the camera, allowing the use of domestic 1, 2 and 3m HDMI leads. The Pi camera HDMI Lead Extension Kit is available from here https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

===USB Cables===

Use short (shortened?) good quality USB cables to connect the EasyCap and RTL-SDR to the RPi. Use of the poor-quality USB cable supplied with the EasyCap has been shown to cause audio dropouts in a streamed signal.

Assembling Portsdown

2022-12-08T19:30:26Z

M0YDH: front panel model link

This section will describe in detail how to assemble your Portsdown transmitter - to begin, you need to have bought or built all the components listed in the [[Portsdown hardware|hardware description.]]

This page describes how to build the complete transmitter assembly but you can run the Portsdown as an experiment in [[QPSKRF or Ugly mode|"Ugly Mode"]], currently labelled in the Menu as QPSKRF. That does not require you to wire anything together.

===Mechanical Design===

First of all, decide on your mechanical design. You are going to need to have the RPi firmly mounted, with the Micro-SD card slot accessible (to change the card if required) and the power, network and USB connectors available. Then you will need to stack a GPIO extender on top of the RPi. A secondhand 3U 19" rack case with mounting rails for vertical circuit cards may well be a good value purchase that is tall enough to take the 7 inch screen if you upgrade to Portsdown 2020 [Portsdown 3] later on. There will be enough room in this for a Minitioune receiver, 71MHz upconverter, all of the Portsdown 2018 hardware, a Lime Mini SDR, voltage converters and maybe some switch gear for amps.

A front panel as CAD models for a 19 inch 3U box is here [[File:Portsdown_3_Front_Panel.zip]] in .dxf and .stp fprmats within a zip archive. The dxf could be printed full size and used as a cutting template.

The most difficult part will be to mount the Touchscreen display. It can either be stacked on top of the RPi, or you can connect it by a short multiway lead and mount it on the front panel of your housing - an example is here: http://www.ebay.co.uk/itm/141354697688. The Waveshare 3.5" touchscreens always seemed to fail during unit construction. If you must use one ask another member for a dead one to use as a template. The official RPi 7 inch touch screen is far superior and mounts well in a 3d printed bezel from a design available from G4XAT.

f you have a 3D printer you could try make up one of these housing http://www.thingiverse.com/thing:1920486

You will then need to consider mounting the ADF4351 Synthesizer, any LO filters and then the Filter/modulator board. Other things to think about might be a 5V power supply, a relay/PTT switching board and any dongles (EasyCap, Sound or RTL-SDR).

The block diagram of what you are trying to achieve is below. Note that you will need an additional filter between the synthesizer and the filter/modulator board for 437 MHz and 146 MHz. It is not required for 1255 MHz, and the unit will work on the other bands for testing without it.

[[File:1-1 Block Diagram.jpg|600px]]

An example layout is here

[[File:In the box.jpg|600px]]

All the circuit cards for Portsdown 2018 except band decode and GPIO Breakout can be mounted on M3 stand-offs on both sides of a rectangle of plain PCB. A housing for a 25 way D connector can be constructed and soldered on. This has sufficient connections to take all the wiring across to the GPIO Breakout. RG402 semi-rigid coax and SMA fittings have been used with Molex KK connectors for the wiring. Pictures are from M0YDH.

[[File:P2020 M0YDH 03.jpg|600px]] [[File:P2020 M0YDH 04.jpg|600px]]

Here are the Portsdown 2018 cards in a Portsdown 2020 and next to the Pi3 - all in a 3U 19 inch rack case.

[[File:P2020 M0YDH 02.jpg|600px]] [[File:P2020 M0YDH 01.jpg|600px]]

===Interconnecting the modules===

The following diagram shows the interconnects between the various modules - all wire can be non screened (except the Local oscillator feed to the Filter modulator board) but should be kept as short as possible.

[[File:Portsdown interconnects.JPG|600px]]

Higher resolution pdf is available here [[:File:Portsdwon interconnect v2.pdf]]

Or a picture might help...

[[File:assembly.JPG|600px]]

===BATC GPIO breakout card===

The GPIO breakout card is where all the signals and power for Portsdown interconnect and we recommend that you buy the blank PCB from the BATC and make up the breakcard using either connectors or hard wiring to the other boards.
For more details see this [[GPIO breakout|wiki page]]

[[File:screw t.jpg|300px]]

[[Willow components breakout card]] (If you have bought the BATC GPIO breakout card you DO NOT NEED to read this section)

===Powering the ADF4351===

The ADF4351 module needs between 5 and 9 volts on its power connector. You can either buy a suitable (small barrel) connector or solder the wires to the underside of the board. The 5V supply can be taken from the same source as the Raspberry Pi 5.2V supply, or from any other 5V supply. It does not need to be very clean. DO NOT try to put 3.3V into the marked pin on the data connector on the module; this is a low current output, not an input.

===RF Wiring===

Use short flexible SMA cables to connect the ADF4351 (through filters if necessary) to the filter/modulator board. Use another cable to take the output to a panel connector or subsequent filters and power amplifiers.

You may also want to extend the input of any RTL-SDR to be accessible from a panel connector.

===Power Supplies and Wiring===

You should power the RPi through the Micro-USB power connector to take advantage of the input protection provided. Use a very short USB cable to your power supply as most of these cables are of very poor quality and cause significant voltage drop. For best results, cut the USB cable 5cm from the connector and run "real" wiring from there to your power supply.

Do not power unnecessary items from the RPi's 5v outputs on the GPIO connector. Doing so will induce extra voltage drop in the input protection circuitry. Power the VCO filter and RF Switch directly from the switch mode power supply. No problems with ripple have been observed.

A lot of strange problems, such as the Portsdown running very slowly, can be caused by low PSU voltage - the RPi3 supply voltage is actually specified as 5.1 volts, so make sure your PSU delivers enough voltage and is capable of sourcing enough current. See [https://forum.batc.org.uk/viewtopic.php?t=4856&p=11935#p11935 this post on the BATC forum] for a real user experience!

If you see a "Lightning Flash" symbol at the top right of your LCD display it means that the voltage at the RPi is too low. You can measure the voltage between the GPIO connector pins 4 and 6.

[[File:flash.jpg|400px]]

You can check if there are any problems by running the command
vcgencmd get_throttled
from the command line. You should get the response "throttled=0x0" which means that all is well. The response "throttled=0x50000" means that the voltage has dropped below the safe level at least once since boot-up; the response "throttled=0x50005" means that the voltage is currently below the safe level. Other responses might mean that your RPi is overheating. The "Info" screen on Menu 3 will also state if there have been any low-voltage events since boot-up.

An eBay buck regulator capable of supplying at least 4A continuous at 5.2V is recommended to power the RPi, an EasyCap, an RTL-SDR and the ADF4351. '''Consumer-grade RPi power supplies with consumer grade USB cables have rarely proved to be capable of supplying this high demand without causing dropouts.'''

The filter/modulator board needs a clean 5V at 250 mA and the on-board linear regulator supplies this, but can get warm at higher input voltages. The linear regulator needs at least 7V to operate properly. Feeding it with 8 volts provides the best compromise between regulator margin and heat dissipation.

You can use a switching or buck converter to supply the filter-modulator board with 5V, but the switching ripple introduces some detectable sidebands on the transmitted signal. These have very little adverse effect, but are visible on a spectrum analyser. On-board switching regulators have been tested, and the pads are there for L10 to provide extra filtering. Again, they introduce low-level sidebands, but these are probably not significant.

===Network and USB Wiring===

Consider bringing the network connector and one of the USB connectors out to the panel for easy access and mechanical stability.

===Camera Wiring===

The RPi camera gives excellent results, but only comes with a short ribbon cable to connect it to the RPi.

It is possible to use some higher quality HDMI leads (the ground connections all need to be made) to extend the camera lead - this does NOT mean the signal out of the camera is HDMI, it is actually "Camera Serial Interface Type 2 (CSI-2)". We are just using HDMI cable as a useful extension lead. The modification described here https://wiki.batc.org.uk/CSI-2_to_HDMI allows the use of lower quality HDMI cables.

Kits are available to connect a female HDMI connector to the RPi camera connector, and another female to the camera, allowing the use of domestic 1, 2 and 3m HDMI leads. The Pi camera HDMI Lead Extension Kit is available from here https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

===USB Cables===

Use short (shortened?) good quality USB cables to connect the EasyCap and RTL-SDR to the RPi. Use of the poor-quality USB cable supplied with the EasyCap has been shown to cause audio dropouts in a streamed signal.

File:Portsdown 3 Front Panel.zip

2022-12-08T19:22:14Z

M0YDH: Here is a .DXF file and a .stp model to load into your CAD software. It is for a 19 inch rack 3U front panel for a Portsdown 2019 with 7" Screen mounted in a G4XAT bezel. Probably the engraving will fail to load. It will import into Front Panel Designer from Schaeffer. STEP files are neutral format CAD models so ought to load into any 3D CAD software.

== Summary ==
Here is a .DXF file and a .stp model to load into your CAD software. It is for a 19 inch rack 3U front panel for a Portsdown 2019 with 7" Screen mounted in a G4XAT bezel. Probably the engraving will fail to load. It will import into Front Panel Designer from Schaeffer. STEP files are neutral format CAD models so ought to load into any 3D CAD software.

71 MHz

2022-09-09T19:24:13Z

M0YDH: /* Equipment for 71MHz DATV */ cost of a converter system

Following access to and progress in the 146-147 MHz band, access for further digital experimentation was negotiated in 2015 to the 70.5-71.5 MHz range, centred on 71.0 MHz. Originally Full licencees had to apply for a Special Research Permit (SRP) using a manual paper process and a number of operators reported problems with their application getting stuck etc.

Following further negotiation, in June 2018 it became more easily available as an annually-renewable NoV available to holders of the Full UK licence. Applications are now done on-line in a similar process to the 146MHz NoV and result in an NoV being issued immediately. See:-

* NoV Form: http://rsgb.org/main/operating/licensing-novs-visitors/online-nov-application/70-5mhz-and-71-5mhz-nov/
* Additional RSGB guidance on 146 and 71 MHz at https://rsgb.org/main/operating/band-plans/vhf-uhf/vhf-spectrum-release/

The NoV allows operation with a maximum of 100W ERP, but prohibits operation within 40 km of the coast or border of Scotland.

==Equipment for 71MHz DATV==

===Transmitter===
Portsdown 2018, Portsdown 2019 and DATV Express are all capable of DATV transmissions on 71MHz.
===Receiver===
Notes for the G0MJW up-converter from CQ-TV260 are available here.

Schematic 

Here is a readable copy of the schematic:

[[File:Schematic.jpg|400px]] 

In the parts list, there may be a bit of confusion over L11 and L15. L11 is only fitted if you are planning to send volts up the coax to provide the bias for the modamp. L15 is the RF choke for the modamp and should be fitted if the PGA103+ modamp is used. You can of course do without the modamp if you have an external pre-amplifier with sufficient gain. Ideally you would run this board just over 2V over the regulator voltage. Using the recommended 3.3V regulator 5V is marginal but probably fine. The PGA103+ takes up to around 100mA. With a 12V supply the regulator will get hot.

The Mini-Circuits Mixer and MMIC amplifiers are stocked by [https://www.minikits.com.au/components/mini-circuits Mini-kits]although an email to Mini-Circuits sales in Surrey (sales@uk.minicircuits.com) would be a best first approach and avoid paying import duty. Update:- Mini-circuits UK advised that applications for EZ Samples of the PGA103+ and ADE-11X+ are acceptable for home constructors. Register with the Mini-Circuits website. Go to the page for one of these parts then press the EZ sample button on the right, fill out the application, reasons and objectives form, add the second item, do the export declaration and press send. Free of charge components arrive a few days later!

SMD Packages 

SMD soldering is easy once you get the hang of it, easier than through hole as you don't have to keep turning the board over. I have left a lot of space around each part to aid construction. Don't use a poker, use a fine tip iron and 0.3mm solder. I didn't notice in the proof but the leading zeros have been left off the SMD package, 805 should be 0805. Most of the SMD parts are in the 0805 size, which is often the largest still commonly available.

The pads for the variable capacitors have been extended to allow for larger components which may be easier to use. The Murata TZC03 series for example is an enormous 3.2x4.5mm and the TZB4 an even larger 4x4.5mm.

The dot on the ADE11x mixer indicates pin 1 and should align with the 1 on the silkscreen.

Other output frequencies 
For other output frequencies, the filter will tune from around 400MHz upto about 700MHz. For lower output frequencies increase the 3.3nH inductor, e.g. to 3.9nH. For higher frequencies reduce it. The tuning is fairly sharp so take your time and do not under any circumstances even consider using a metal screwdriver to tune it up.

Other input frequencies 
There is no reason to be limited to 50-70MHz. This will work at 2m too but the input filter will need to be modified, ideally to a band pass to keep out the broadcast band. The board had been designed to allow several different filter topologies.

Modamp 
You do not have to use a PGA-103+. Other similar devices like the SPF5189z will work. If you already have a pre-amplifier with sufficient gain, say 20dB or more, the modamp can be bypassed and there is no need for a power supply or regulator.

Impact of inductor Q 

Not all SMD inductors are of the same quality factor (Q). For filters it is important to use high Q components, otherwise the filter will be lossy and may not have the expected performance. The two 3.3nH inductors in the output filter are probably the most critical, parts are preferred with a Q of 30 or more and will result in a filter loss of 4-5dB. Not great, but a fair compromise. If you use low Q inductors, (some cheaper ones are as low as 10), it will work, but the output filter will have more loss.

Good inductor Q = 38, e.g. AVX L08053R3DEWTR or Coilcraft 0805CS-030XJLC
 

[[File:BPFQ38.jpg|400px]]
 
Moderate inductor Q = 16
 
[[File:BPFQ16.jpg|400px]]
 
Awful inductor Q = 10
 
[[File:BPFQ10.jpg|400px]]

[https://youtu.be/D9r-Zb_YhsU A video of an upconverter in action by David M0YDH is here.]

THis picture shows a later upconverter system built by M0YDH. Clockwise from bottom right:- 12V in and 5V regulated supply // BATC PIC card with program for 400MHz to control the sysnthesiser // ADF4351 synthesiser as LO // EBay 400- 470 MHz low pass filter // SPF5189Z amp // G0MJW upconverter card with -6dB attenuation// pair of G0MJW RF SPDT relay boards / The Normally Closed bypass line in SMA fittings. One switch on the unit front panel when turned on energises the upconverter. The other side of the plain PCB card has a Minitioune v1.5 mounted on it.

[[File:M0YDH Upconverter.jpg|600px]] The assembly shown cost about £85 to put together in 2022 [the ADF4351 was bought for £10 secondhand]

===Antennas===
Before buying or building a beam here are two low cost designs to get you onto the band

1) [https://sites.google.com/site/gw7aav2/70mhz(4metre)deltaloop A 4m delta loop by Steve GW7AAV]. David M0YDH made one of these some years ago for SOTA and it was a VSWR approaching 1:1 straight away. Old TV coax is used for the matching section. Electrical conduit is used for the boom [not flimsy waste water pipe!]. You could fasten two mini telescopic masts to a plastic bread board with pipe clamps to support the wire triangle. [https://sites.google.com/site/gw7aav2/50mhzdeltaloop There is a 6m version on the site too.] Also a combined pair of these antennas are shown on the 4m page.

2)[http://www.70mhz.org/coaxdipole.htm A centre-fed "co-axial" dipole for 4m by Tony G4CJZ] was built quickly be Noel G8GTZ with acceptable results to get on the band.

===Filters===
These are in the [[70MHz_filters|Filters section of this Wiki]].

Portsdown hardware

2022-09-09T17:19:38Z

M0YDH: /* Optional RPi camera Extension Lead Kit */ Pimoroni is the only possible stockist

This page describes all the hardware modules and interconnections required to build the Portsdown DATV system.

Not all the hardware is required before the transmitter can start to be tested – an incremental approach is described here to allow constructors to gain confidence as they assemble the parts.

===Raspberry Pi ===

The first item required is a standard Raspberry Pi - this can be a Pi 3 or Pi 4 depending upon the Portsdown version you are building. These are available from many suppliers and we suggest you just buy a Raspberry Pi without any additional boards or SD cards as you will be using specific Portsdown hardware and software. If you are starting a new build, the Raspberry Pi 4 Model B with 2 GB of RAM is recommended (4 GB or 8 GB or RAM will work, but costs more for no performance advantage).

The Raspberry Pi 4 can run hot, so using a heatsink case or fan to cool it is recommended.

===Power Supplies ===

You will also need a GOOD 3amp 5v power supply for the Raspberry Pi.

You should power a Pi 4 via the GPIO pins but always power a RPi 3 through the Micro-USB power connector to take advantage of the input protection provided. Use a very short USB cable to your power supply as most of these cables are of very poor quality and cause a significant voltage drop.

If you see a "Lightning Flash" symbol at the top right of your LCD display it means that the voltage at the RPi is too low. You can measure the voltage between the GPIO connector pins 4 and 6.

[[File:flash.jpg|200px]]

A lot of strange problems, such as the Portsdown running very slowly, can be caused by poor PSU volts - the RPi is actually specified for 5.1 volts, so make sure that your PSU delivers enough volts and current. See [https://forum.batc.org.uk/viewtopic.php?t=4856&p=11935#p11935 this post on the BATC forum] for a real user experience!

You may also need a 12 volt DC supply to power the other Portsdown components.

===Micro-SD Card===

You then need an SD card with the Portsdown software on it.

The easiest way is to buy a pre-programmed SD Card from the [https://batc.org.uk/shop/portsdown-transmitter-pre-programmed-sd-card/ BATC shop].

OR if you want to have a go at loading the software yourself you will need to or purchase a '''good quality card''' from another source and follow the instructions described [[Portsdown software|here]]. The 8 GB, 16 GB or 32 GB SanDisk Ultra (the red and grey one) is recommended - DO NOT use cheap copies.

===LCD Touchscreen===

The touchscreen is required to control the transmitter without the use of another computer.

'''Do not buy a touchscreen that connects through the RPi HDMI connector - it is NOT supported.'''

===7" Touchscreen===

The Portsdown 4 is designed to work with the Official Raspberry Pi 7" touchscreen (often referred to as a "7 inch Element 14 touchscreen"). The Portsdown 2020 works best with this screen, but can also use the 3.5 inch screen (below). The Portsdown 4 also supports the DFRobot DFR0550 5 inch touchscreen.

[[File:7_inch_screen.jpg|400px]]

Note that if you use the 7-inch screen, you do not need to connect the 3 data leads between the screen and the RPi - only ground and +5v.

===5" Touchscreen===

The Portsdown 4 (from software release 202203071) supports the DFRobot DFR0550 Touchscreen. However, on initial build, the Portsdown touch map is rotated by 180 degrees. This can be corrected by navigating to Menu 3, System Config, Invert Touchscreen. If you can’t work out exactly where to press, here are the touch points:
# Preset 1 (Menu 3 should then be displayed)
# M2 (the System Configuration Menu should then be displayed)
# Just above Web Control (the reboot question should then be displayed)
# The "d" of inverted (the system should then reboot)

After the reboot, you should again go to Menu 3, System Config and select the 5 inch screen to get a reliable response to touches.

===3.5" OSOYOO DSI Touchscreen===

Hubertus DC1OP has reported that the OSOYOO 3.5 Inch DSI Touchscreen LCD Display also works with the Portsdown 4 in the same way as the DFRobot 5 inch screen - it needs the touchmap to be rotated as for the 5 inch screen. This has not been tested by the development team, so purchase at your own risk!

This screen can be found on Amazon: https://www.amazon.co.uk/OSOYOO-Capacitive-Connector-Resolution-Raspberry/dp/B087WVC1J2

The key enabler is that it is a DSI-connected screen with 800x480 resolution. Note that DPI-connected, or different resolution touchscreens WILL NOT work with the Portsdown.

===3.5" Waveshare Touchscreen===

'''Note this is NOT supported on the Portsdown 4.'''

The other supported touchscreen on Portsdown 2020 is a 3.5 inch diagonal Waveshare Raspberry Pi LCD (Model A, not Model B).

To mount the Waveshare screen away from the RPi, you could use this extension cable: https://thepihut.com/products/adafruit-gpio-extender-cable-for-raspberry-pi-model-a-b-26pin-12-long Just make sure that you triple-check the connections and pin orientation before connecting the screen. They do not tolerate incorrect connection as several of us have found out! Alternatively, you can make one yourself from a discarded 3.5 inch floppy drive and its lead.

Further information on screens can be found here [[Portsdown Displays]] and information on display resolutions can be found here [[Display Resolutions|PAL/NTSC and Display Resolutions]].

Mounting the Waveshare LCD Touchscreen can be a challenge! This 3D print design mounts it flat to the panel: https://www.thingiverse.com/thing:1941701
This 3D print design mounts it at an angle: https://www.thingiverse.com/thing:1920486.

Note that, when mounted, none of the touchscreen sensitive areas should be in contact with the surround.

===GPIO Extender Card===

In the completed unit, there are a number of signals that need to be routed in or out of the GPIO interface on the RPi. Plus we need to break out all 40 pins of the GPIO, and have another connector on top for the Waveshare LCD display (if used). Because of this the Portsdown team have designed a PCB for the job - the blank PCB for this is available from the BATC shop.

Buying an extender card early in the project reduces the chance of damage to the RPi and allows these connections to be made safely.

[[File:screw t.jpg|400px]]

The BATC card is very simple to construct with no components other than plugs and sockets.

For full construction details and a list of suppliers for the plugs and sockets see [[GPIO breakout|the GPIO breakout page]]

You can buy the GPIO Extender Card blank PCB from the [https://batc.org.uk/shop/portsdown-transmitter-gpio-breakout-board-blank-pcb/ Portsdown section in the BATC shop - item 3]

===LimeSDR ===

The Portsdown system can use the LimeSDR Mini (or LimeSDR USB) to provide the modulator and RF generator functions.

[[File:LimeMini.jpg|400px]]

[[Using LimeSDR with Portsdown|See this page]] for more details on using the LimeSDR in a Portsdown system.

===Pluto SDR===

The Portsdown 4 uses the Pluto SDR connected via the USB port to provide the modulator and RF generator functions.

See this page for more details: [[Portsdown_4_Pluto]]

----------------------

'''You now have the components for a fully working Portsdown transmitter!

---------------------

'''''However, you will need a camera and audio input to transmit pictures and sound.'''''

===Raspberry Pi Camera===

If you want to transmit live pictures you will need a camera. The standard Pi camera gives excellent results but will need mounting in a housing and does not have audio input.

Raspberry Pi Camera: CPC Farnell http://cpc.farnell.com/raspberry-pi/rpi-8mp-camera-board/raspberry-pi-camera-board-8mp/dp/SC14028

===Optional RPi camera Extension Lead Kit===

The RPi camera gives excellent results, but only comes with a short ribbon cable to connect it to the RPi.

It is possible to use some higher quality HDMI leads (the ground connections all need to be made) to extend the camera lead - this does NOT mean the signal out of the camera is HDMI, it is actually "Camera Serial Interface Type 2 (CSI-2)". We are just using HDMI cable as a useful extension lead.

Kits are available to connect a female HDMI connector to the RPi camera connector, and another female to the camera, allowing the use of domestic 1, 2 and 3m HDMI leads.The maker is Petite Studio

RPi Camera HDMI Lead Extension Kit: https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

In the UK and most of the world it's best to get [https://shop.pimoroni.com/products/pi-camera-hdmi-cable-extension?variant=4585578945 the Petite Studio kit at Pimoroni]. It's called Raspberry Pi Camera HDMI Cable Extension.

There are 2 modifications that can be made to enable lower quality HDMI leads (those without all the ground connections made, or even the CEC wire on pin 13 missing) to be used. Full details of these modifications [[CSI-2 to HDMI|are available here.]]

===WebCams===

Some WebCams work with the Portsdown, but it has proved very difficult to support more than a few specific models. The Portsdown 2020 works with the older (pre-2019) versions of the Logitech C920. The Portsdown 4 works with all (3) versions of the C920 and with the Logitech C170. More details on webcams here [[Portsdown Webcams]].

===Composite Video Capture Device===

The transmitter is also capable of working with a USB-connected “EasyCap” dongle to capture PAL composite video from camcorders and analogue mixers etc.

There are at least 4 similar devices being marketed under this name on eBay, each with different chipsets, but only the Fushicai "USBTV007" brand is guaranteed to work.

[[File:Fushicai.JPG|200px]]

===Audio Capture Device===

eBay provides a good source for very cheap audio capture USB dongles, which can provide an audio input to go with the RPi camera. The audio capuure device must be of the type shown here:

[[File:04 USB Audio.png|200px]]

Other stand-alone USB audio capture devices may not work and the software will not be changed to support them. Please don't ask.

This type of audio capture device is also compatible with the Ryde DATV Receiver and the Langstone Microwave transceiver.

-----------------------------
'''That completes the basic Portsdown transmitter shopping list'''

---------------------
'''''However, the team has designed some additional components to enable you to build a complete DATV transmit system'''''

===RF Switching===

The complete RF switching arrangement illustrated below allows you to select the output from the Lime SDR or Pluto, adjust the exact level and then route the RF to any one of 8 PAs or transverters. All the blocks in the diagram are optional; however, you can build a very comprehensive system if you want to. Note that the 4-way decode and switch boards can be substituted for the 8-way decode and switch boards.

[[File:20190511 Portsdown RF Switching.jpg|600px]]

===4-Band RF Output Switch===

The Portsdown team have developed a 4-Band RF output switch capable of switching the low level output of the Lime Mini / Pluto to separate amplifiers for the 70, 144, 437 and 1255 MHz bands. Note: due to potential high insertion loss, it is not recommended to use the switch above 23cms.

[[File:Pd out SW.jpg|300px]]

Full details including parts list and schematic are available [[RF output switch|on this wiki page]].

===4-Band Decode Switch===

The Portsdown provides band switching and PTT outputs on the GPIO pins - these outputs need to be decoded to provide an output for each band.

[[File:Band decoder.JPG|200px]]

The Portsdown team have designed a simple board for switching between 4 bands and buffering the PTT signal which can be either constructed on 0.1” perforated board (veroboard) or on a PCB - this can be home etched.
Full details on the board including circuit etc [[PTT and band switching|are available here.]]
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-transmitter-4-band-decode-blank-pcb/ BATC shop - item 5].

===8-Band RF Output Switch===

For those of you who also want to drive Microwave transverters from your Portsdown, the team have developed an 8-Band RF output switch that includes an RF amplifier. It is designed to be used with the Output Attenuator (see below). It will be capable of amplifying the variable level from the attenuator and switching it to separate amplifiers for the 70, 144, 437 and 1255 MHz bands, and to 4 transverters for the higher bands. PCBs are on order and will be available from the BATC Shop.

Full details including parts list and schematic are available [[8-Band RF Output Switch|on this wiki page]].
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-way-rf-output-switch-blank-pcb/ BATC shop - item 9].

===8-Band Decoder===

This 8-band decoder is designed to work with the 8-band RF output switch and the Portsdown software. It will provide switching signals (either always on, or PTT activated) to 4 Power Amplifiers and 4 transverters, and it also enables you to set which VCO filter should be switched in for the 4 transverter outputs. PCBs are on order and will be available from the BATC Shop.

Full details on the board including circuit etc [[8-Band Decoder|are available here.]]
Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-band-decode-blank-pcb/ BATC shop - item 7].

===8-Band Decode PIC===

This is the pre=programmed PIC to control the custom designed 8 band decode board for the Portsdown transmitter.

Blank PCBs are available in the [https://batc.org.uk/shop/portsdown-8-band-decode-pic/ BATC shop - item 8].

===2-Way RF Switch===

Not required for Portsdown 4.

This switch allows you to route the outputs from the Portsdown 2017 Filter Modulator card and a LimeSDR to a single PA, enabling both to be used without reconfiguration. Full details on this Wiki page [[2-Way RF Switch]].

===Filters and PA drivers===

It is absolutely essential that the Portsdown transmitter output is followed by suitable bandpass filters.
These are not included as part of the project but a [[Filters|number of designs and suppliers are listed here.]]

===Output Attenuator===

Although NOT required when using the Lime Mini or Pluto SDR, the Portsdown can use an electronically switched attenuator to adjust the transmit drive level for each band. Attenuators based on the PE4302, HMC1119 or PE43703 (preferred) are supported.

[[File:PE43073 post-mod small.jpg|400px]]

These attenuators are available on eBay. Full details and wiring instructions are detailed here: [[Output Attenuator]].

71 MHz

2022-08-12T14:07:00Z

M0YDH: /* Antennas */

Following access to and progress in the 146-147 MHz band, access for further digital experimentation was negotiated in 2015 to the 70.5-71.5 MHz range, centred on 71.0 MHz. Originally Full licencees had to apply for a Special Research Permit (SRP) using a manual paper process and a number of operators reported problems with their application getting stuck etc.

Following further negotiation, in June 2018 it became more easily available as an annually-renewable NoV available to holders of the Full UK licence. Applications are now done on-line in a similar process to the 146MHz NoV and result in an NoV being issued immediately. See:-

* NoV Form: http://rsgb.org/main/operating/licensing-novs-visitors/online-nov-application/70-5mhz-and-71-5mhz-nov/
* Additional RSGB guidance on 146 and 71 MHz at https://rsgb.org/main/operating/band-plans/vhf-uhf/vhf-spectrum-release/

The NoV allows operation with a maximum of 100W ERP, but prohibits operation within 40 km of the coast or border of Scotland.

==Equipment for 71MHz DATV==

===Transmitter===
Portsdown 2018, Portsdown 2019 and DATV Express are all capable of DATV transmissions on 71MHz.
===Receiver===
Notes for the G0MJW up-converter from CQ-TV260 are available here.

Schematic 

Here is a readable copy of the schematic:

[[File:Schematic.jpg|400px]] 

In the parts list, there may be a bit of confusion over L11 and L15. L11 is only fitted if you are planning to send volts up the coax to provide the bias for the modamp. L15 is the RF choke for the modamp and should be fitted if the PGA103+ modamp is used. You can of course do without the modamp if you have an external pre-amplifier with sufficient gain. Ideally you would run this board just over 2V over the regulator voltage. Using the recommended 3.3V regulator 5V is marginal but probably fine. The PGA103+ takes up to around 100mA. With a 12V supply the regulator will get hot.

The Mini-Circuits Mixer and MMIC amplifiers are stocked by [https://www.minikits.com.au/components/mini-circuits Mini-kits]although an email to Mini-Circuits sales in Surrey (sales@uk.minicircuits.com) would be a best first approach and avoid paying import duty. Update:- Mini-circuits UK advised that applications for EZ Samples of the PGA103+ and ADE-11X+ are acceptable for home constructors. Register with the Mini-Circuits website. Go to the page for one of these parts then press the EZ sample button on the right, fill out the application, reasons and objectives form, add the second item, do the export declaration and press send. Free of charge components arrive a few days later!

SMD Packages 

SMD soldering is easy once you get the hang of it, easier than through hole as you don't have to keep turning the board over. I have left a lot of space around each part to aid construction. Don't use a poker, use a fine tip iron and 0.3mm solder. I didn't notice in the proof but the leading zeros have been left off the SMD package, 805 should be 0805. Most of the SMD parts are in the 0805 size, which is often the largest still commonly available.

The pads for the variable capacitors have been extended to allow for larger components which may be easier to use. The Murata TZC03 series for example is an enormous 3.2x4.5mm and the TZB4 an even larger 4x4.5mm.

The dot on the ADE11x mixer indicates pin 1 and should align with the 1 on the silkscreen.

Other output frequencies 
For other output frequencies, the filter will tune from around 400MHz upto about 700MHz. For lower output frequencies increase the 3.3nH inductor, e.g. to 3.9nH. For higher frequencies reduce it. The tuning is fairly sharp so take your time and do not under any circumstances even consider using a metal screwdriver to tune it up.

Other input frequencies 
There is no reason to be limited to 50-70MHz. This will work at 2m too but the input filter will need to be modified, ideally to a band pass to keep out the broadcast band. The board had been designed to allow several different filter topologies.

Modamp 
You do not have to use a PGA-103+. Other similar devices like the SPF5189z will work. If you already have a pre-amplifier with sufficient gain, say 20dB or more, the modamp can be bypassed and there is no need for a power supply or regulator.

Impact of inductor Q 

Not all SMD inductors are of the same quality factor (Q). For filters it is important to use high Q components, otherwise the filter will be lossy and may not have the expected performance. The two 3.3nH inductors in the output filter are probably the most critical, parts are preferred with a Q of 30 or more and will result in a filter loss of 4-5dB. Not great, but a fair compromise. If you use low Q inductors, (some cheaper ones are as low as 10), it will work, but the output filter will have more loss.

Good inductor Q = 38, e.g. AVX L08053R3DEWTR or Coilcraft 0805CS-030XJLC
 

[[File:BPFQ38.jpg|400px]]
 
Moderate inductor Q = 16
 
[[File:BPFQ16.jpg|400px]]
 
Awful inductor Q = 10
 
[[File:BPFQ10.jpg|400px]]

[https://youtu.be/D9r-Zb_YhsU A video of an upconverter in action by David M0YDH is here.]

THis picture shows a later upconverter system built by M0YDH. Clockwise from bottom right:- 12V in and 5V regulated supply // BATC PIC card with program for 400MHz to control the sysnthesiser // ADF4351 synthesiser as LO // EBay 400- 470 MHz low pass filter // SPF5189Z amp // G0MJW upconverter card with -6dB attenuation// pair of G0MJW RF SPDT relay boards / The Normally Closed bypass line in SMA fittings. One switch on the unit front panel when turned on energises the upconverter. The other side of the plain PCB card has a Minitioune v1.5 mounted on it.

[[File:M0YDH Upconverter.jpg|600px]]

===Antennas===
Before buying or building a beam here are two low cost designs to get you onto the band

1) [https://sites.google.com/site/gw7aav2/70mhz(4metre)deltaloop A 4m delta loop by Steve GW7AAV]. David M0YDH made one of these some years ago for SOTA and it was a VSWR approaching 1:1 straight away. Old TV coax is used for the matching section. Electrical conduit is used for the boom [not flimsy waste water pipe!]. You could fasten two mini telescopic masts to a plastic bread board with pipe clamps to support the wire triangle. [https://sites.google.com/site/gw7aav2/50mhzdeltaloop There is a 6m version on the site too.] Also a combined pair of these antennas are shown on the 4m page.

2)[http://www.70mhz.org/coaxdipole.htm A centre-fed "co-axial" dipole for 4m by Tony G4CJZ] was built quickly be Noel G8GTZ with acceptable results to get on the band.

===Filters===
These are in the [[70MHz_filters|Filters section of this Wiki]].

71 MHz

2022-08-12T14:03:53Z

M0YDH: /* Antennas */ 6m url too

Following access to and progress in the 146-147 MHz band, access for further digital experimentation was negotiated in 2015 to the 70.5-71.5 MHz range, centred on 71.0 MHz. Originally Full licencees had to apply for a Special Research Permit (SRP) using a manual paper process and a number of operators reported problems with their application getting stuck etc.

Following further negotiation, in June 2018 it became more easily available as an annually-renewable NoV available to holders of the Full UK licence. Applications are now done on-line in a similar process to the 146MHz NoV and result in an NoV being issued immediately. See:-

* NoV Form: http://rsgb.org/main/operating/licensing-novs-visitors/online-nov-application/70-5mhz-and-71-5mhz-nov/
* Additional RSGB guidance on 146 and 71 MHz at https://rsgb.org/main/operating/band-plans/vhf-uhf/vhf-spectrum-release/

The NoV allows operation with a maximum of 100W ERP, but prohibits operation within 40 km of the coast or border of Scotland.

==Equipment for 71MHz DATV==

===Transmitter===
Portsdown 2018, Portsdown 2019 and DATV Express are all capable of DATV transmissions on 71MHz.
===Receiver===
Notes for the G0MJW up-converter from CQ-TV260 are available here.

Schematic 

Here is a readable copy of the schematic:

[[File:Schematic.jpg|400px]] 

In the parts list, there may be a bit of confusion over L11 and L15. L11 is only fitted if you are planning to send volts up the coax to provide the bias for the modamp. L15 is the RF choke for the modamp and should be fitted if the PGA103+ modamp is used. You can of course do without the modamp if you have an external pre-amplifier with sufficient gain. Ideally you would run this board just over 2V over the regulator voltage. Using the recommended 3.3V regulator 5V is marginal but probably fine. The PGA103+ takes up to around 100mA. With a 12V supply the regulator will get hot.

The Mini-Circuits Mixer and MMIC amplifiers are stocked by [https://www.minikits.com.au/components/mini-circuits Mini-kits]although an email to Mini-Circuits sales in Surrey (sales@uk.minicircuits.com) would be a best first approach and avoid paying import duty. Update:- Mini-circuits UK advised that applications for EZ Samples of the PGA103+ and ADE-11X+ are acceptable for home constructors. Register with the Mini-Circuits website. Go to the page for one of these parts then press the EZ sample button on the right, fill out the application, reasons and objectives form, add the second item, do the export declaration and press send. Free of charge components arrive a few days later!

SMD Packages 

SMD soldering is easy once you get the hang of it, easier than through hole as you don't have to keep turning the board over. I have left a lot of space around each part to aid construction. Don't use a poker, use a fine tip iron and 0.3mm solder. I didn't notice in the proof but the leading zeros have been left off the SMD package, 805 should be 0805. Most of the SMD parts are in the 0805 size, which is often the largest still commonly available.

The pads for the variable capacitors have been extended to allow for larger components which may be easier to use. The Murata TZC03 series for example is an enormous 3.2x4.5mm and the TZB4 an even larger 4x4.5mm.

The dot on the ADE11x mixer indicates pin 1 and should align with the 1 on the silkscreen.

Other output frequencies 
For other output frequencies, the filter will tune from around 400MHz upto about 700MHz. For lower output frequencies increase the 3.3nH inductor, e.g. to 3.9nH. For higher frequencies reduce it. The tuning is fairly sharp so take your time and do not under any circumstances even consider using a metal screwdriver to tune it up.

Other input frequencies 
There is no reason to be limited to 50-70MHz. This will work at 2m too but the input filter will need to be modified, ideally to a band pass to keep out the broadcast band. The board had been designed to allow several different filter topologies.

Modamp 
You do not have to use a PGA-103+. Other similar devices like the SPF5189z will work. If you already have a pre-amplifier with sufficient gain, say 20dB or more, the modamp can be bypassed and there is no need for a power supply or regulator.

Impact of inductor Q 

Not all SMD inductors are of the same quality factor (Q). For filters it is important to use high Q components, otherwise the filter will be lossy and may not have the expected performance. The two 3.3nH inductors in the output filter are probably the most critical, parts are preferred with a Q of 30 or more and will result in a filter loss of 4-5dB. Not great, but a fair compromise. If you use low Q inductors, (some cheaper ones are as low as 10), it will work, but the output filter will have more loss.

Good inductor Q = 38, e.g. AVX L08053R3DEWTR or Coilcraft 0805CS-030XJLC
 

[[File:BPFQ38.jpg|400px]]
 
Moderate inductor Q = 16
 
[[File:BPFQ16.jpg|400px]]
 
Awful inductor Q = 10
 
[[File:BPFQ10.jpg|400px]]

[https://youtu.be/D9r-Zb_YhsU A video of an upconverter in action by David M0YDH is here.]

THis picture shows a later upconverter system built by M0YDH. Clockwise from bottom right:- 12V in and 5V regulated supply // BATC PIC card with program for 400MHz to control the sysnthesiser // ADF4351 synthesiser as LO // EBay 400- 470 MHz low pass filter // SPF5189Z amp // G0MJW upconverter card with -6dB attenuation// pair of G0MJW RF SPDT relay boards / The Normally Closed bypass line in SMA fittings. One switch on the unit front panel when turned on energises the upconverter. The other side of the plain PCB card has a Minitioune v1.5 mounted on it.

[[File:M0YDH Upconverter.jpg|600px]]

===Antennas===
Before buying or building a beam here are two low cost designs to get you onto the band

1) [https://sites.google.com/site/gw7aav2/70mhz(4metre)deltaloop A 4m delta loop by Steve GW7AAV]. David M0YDH made one of these some years ago for SOTA and it was a VSWR approaching 1:1 straight away. Old TV coax is used for the matching section. Electrical conduit is used for the boom [not flimsy waste water pipe!]. You could fasten two mini telescopic masts to a plastic bread board with pipe clamps to support the wire triangle. [https://sites.google.com/site/gw7aav2/50mhzdeltaloop There is a 6m version on the site too.] Also a combined pair of these antennas are shoen.

2)[http://www.70mhz.org/coaxdipole.htm A centre-fed "co-axial" dipole for 4m by Tony G4CJZ] was built quickly be Noel G8GTZ with acceptable results to get on the band.

===Filters===
These are in the [[70MHz_filters|Filters section of this Wiki]].

71 MHz

2022-08-12T14:02:06Z

M0YDH: /* Antennas */ revised URL

Following access to and progress in the 146-147 MHz band, access for further digital experimentation was negotiated in 2015 to the 70.5-71.5 MHz range, centred on 71.0 MHz. Originally Full licencees had to apply for a Special Research Permit (SRP) using a manual paper process and a number of operators reported problems with their application getting stuck etc.

Following further negotiation, in June 2018 it became more easily available as an annually-renewable NoV available to holders of the Full UK licence. Applications are now done on-line in a similar process to the 146MHz NoV and result in an NoV being issued immediately. See:-

* NoV Form: http://rsgb.org/main/operating/licensing-novs-visitors/online-nov-application/70-5mhz-and-71-5mhz-nov/
* Additional RSGB guidance on 146 and 71 MHz at https://rsgb.org/main/operating/band-plans/vhf-uhf/vhf-spectrum-release/

The NoV allows operation with a maximum of 100W ERP, but prohibits operation within 40 km of the coast or border of Scotland.

==Equipment for 71MHz DATV==

===Transmitter===
Portsdown 2018, Portsdown 2019 and DATV Express are all capable of DATV transmissions on 71MHz.
===Receiver===
Notes for the G0MJW up-converter from CQ-TV260 are available here.

Schematic 

Here is a readable copy of the schematic:

[[File:Schematic.jpg|400px]] 

In the parts list, there may be a bit of confusion over L11 and L15. L11 is only fitted if you are planning to send volts up the coax to provide the bias for the modamp. L15 is the RF choke for the modamp and should be fitted if the PGA103+ modamp is used. You can of course do without the modamp if you have an external pre-amplifier with sufficient gain. Ideally you would run this board just over 2V over the regulator voltage. Using the recommended 3.3V regulator 5V is marginal but probably fine. The PGA103+ takes up to around 100mA. With a 12V supply the regulator will get hot.

The Mini-Circuits Mixer and MMIC amplifiers are stocked by [https://www.minikits.com.au/components/mini-circuits Mini-kits]although an email to Mini-Circuits sales in Surrey (sales@uk.minicircuits.com) would be a best first approach and avoid paying import duty. Update:- Mini-circuits UK advised that applications for EZ Samples of the PGA103+ and ADE-11X+ are acceptable for home constructors. Register with the Mini-Circuits website. Go to the page for one of these parts then press the EZ sample button on the right, fill out the application, reasons and objectives form, add the second item, do the export declaration and press send. Free of charge components arrive a few days later!

SMD Packages 

SMD soldering is easy once you get the hang of it, easier than through hole as you don't have to keep turning the board over. I have left a lot of space around each part to aid construction. Don't use a poker, use a fine tip iron and 0.3mm solder. I didn't notice in the proof but the leading zeros have been left off the SMD package, 805 should be 0805. Most of the SMD parts are in the 0805 size, which is often the largest still commonly available.

The pads for the variable capacitors have been extended to allow for larger components which may be easier to use. The Murata TZC03 series for example is an enormous 3.2x4.5mm and the TZB4 an even larger 4x4.5mm.

The dot on the ADE11x mixer indicates pin 1 and should align with the 1 on the silkscreen.

Other output frequencies 
For other output frequencies, the filter will tune from around 400MHz upto about 700MHz. For lower output frequencies increase the 3.3nH inductor, e.g. to 3.9nH. For higher frequencies reduce it. The tuning is fairly sharp so take your time and do not under any circumstances even consider using a metal screwdriver to tune it up.

Other input frequencies 
There is no reason to be limited to 50-70MHz. This will work at 2m too but the input filter will need to be modified, ideally to a band pass to keep out the broadcast band. The board had been designed to allow several different filter topologies.

Modamp 
You do not have to use a PGA-103+. Other similar devices like the SPF5189z will work. If you already have a pre-amplifier with sufficient gain, say 20dB or more, the modamp can be bypassed and there is no need for a power supply or regulator.

Impact of inductor Q 

Not all SMD inductors are of the same quality factor (Q). For filters it is important to use high Q components, otherwise the filter will be lossy and may not have the expected performance. The two 3.3nH inductors in the output filter are probably the most critical, parts are preferred with a Q of 30 or more and will result in a filter loss of 4-5dB. Not great, but a fair compromise. If you use low Q inductors, (some cheaper ones are as low as 10), it will work, but the output filter will have more loss.

Good inductor Q = 38, e.g. AVX L08053R3DEWTR or Coilcraft 0805CS-030XJLC
 

[[File:BPFQ38.jpg|400px]]
 
Moderate inductor Q = 16
 
[[File:BPFQ16.jpg|400px]]
 
Awful inductor Q = 10
 
[[File:BPFQ10.jpg|400px]]

[https://youtu.be/D9r-Zb_YhsU A video of an upconverter in action by David M0YDH is here.]

THis picture shows a later upconverter system built by M0YDH. Clockwise from bottom right:- 12V in and 5V regulated supply // BATC PIC card with program for 400MHz to control the sysnthesiser // ADF4351 synthesiser as LO // EBay 400- 470 MHz low pass filter // SPF5189Z amp // G0MJW upconverter card with -6dB attenuation// pair of G0MJW RF SPDT relay boards / The Normally Closed bypass line in SMA fittings. One switch on the unit front panel when turned on energises the upconverter. The other side of the plain PCB card has a Minitioune v1.5 mounted on it.

[[File:M0YDH Upconverter.jpg|600px]]

===Antennas===
Before buying or building a beam here are two low cost designs to get you onto the band

1) [https://sites.google.com/site/gw7aav2/70mhz(4metre)deltaloop A 4m delta loop by Steve GW7AAV]. David M0YDH made one of these some years ago for SOTA and it was a VSWR approaching 1:1 straight away. Old TV coax is used for the matching section. Electrical conduit is used for the boom [not flimsy waste water pipe!]. You could fasten two mini telescopic masts to a plastic bread board with pipe clamps to support the wire triangle. There is a 6m version on the site too.

2)[http://www.70mhz.org/coaxdipole.htm A centre-fed "co-axial" dipole for 4m by Tony G4CJZ] was built quickly be Noel G8GTZ with acceptable results to get on the band.

===Filters===
These are in the [[70MHz_filters|Filters section of this Wiki]].

71 MHz

2022-08-12T13:46:26Z

M0YDH: /* Receiver */ M0YDH upconverter number 2

Following access to and progress in the 146-147 MHz band, access for further digital experimentation was negotiated in 2015 to the 70.5-71.5 MHz range, centred on 71.0 MHz. Originally Full licencees had to apply for a Special Research Permit (SRP) using a manual paper process and a number of operators reported problems with their application getting stuck etc.

Following further negotiation, in June 2018 it became more easily available as an annually-renewable NoV available to holders of the Full UK licence. Applications are now done on-line in a similar process to the 146MHz NoV and result in an NoV being issued immediately. See:-

* NoV Form: http://rsgb.org/main/operating/licensing-novs-visitors/online-nov-application/70-5mhz-and-71-5mhz-nov/
* Additional RSGB guidance on 146 and 71 MHz at https://rsgb.org/main/operating/band-plans/vhf-uhf/vhf-spectrum-release/

The NoV allows operation with a maximum of 100W ERP, but prohibits operation within 40 km of the coast or border of Scotland.

==Equipment for 71MHz DATV==

===Transmitter===
Portsdown 2018, Portsdown 2019 and DATV Express are all capable of DATV transmissions on 71MHz.
===Receiver===
Notes for the G0MJW up-converter from CQ-TV260 are available here.

Schematic 

Here is a readable copy of the schematic:

[[File:Schematic.jpg|400px]] 

In the parts list, there may be a bit of confusion over L11 and L15. L11 is only fitted if you are planning to send volts up the coax to provide the bias for the modamp. L15 is the RF choke for the modamp and should be fitted if the PGA103+ modamp is used. You can of course do without the modamp if you have an external pre-amplifier with sufficient gain. Ideally you would run this board just over 2V over the regulator voltage. Using the recommended 3.3V regulator 5V is marginal but probably fine. The PGA103+ takes up to around 100mA. With a 12V supply the regulator will get hot.

The Mini-Circuits Mixer and MMIC amplifiers are stocked by [https://www.minikits.com.au/components/mini-circuits Mini-kits]although an email to Mini-Circuits sales in Surrey (sales@uk.minicircuits.com) would be a best first approach and avoid paying import duty. Update:- Mini-circuits UK advised that applications for EZ Samples of the PGA103+ and ADE-11X+ are acceptable for home constructors. Register with the Mini-Circuits website. Go to the page for one of these parts then press the EZ sample button on the right, fill out the application, reasons and objectives form, add the second item, do the export declaration and press send. Free of charge components arrive a few days later!

SMD Packages 

SMD soldering is easy once you get the hang of it, easier than through hole as you don't have to keep turning the board over. I have left a lot of space around each part to aid construction. Don't use a poker, use a fine tip iron and 0.3mm solder. I didn't notice in the proof but the leading zeros have been left off the SMD package, 805 should be 0805. Most of the SMD parts are in the 0805 size, which is often the largest still commonly available.

The pads for the variable capacitors have been extended to allow for larger components which may be easier to use. The Murata TZC03 series for example is an enormous 3.2x4.5mm and the TZB4 an even larger 4x4.5mm.

The dot on the ADE11x mixer indicates pin 1 and should align with the 1 on the silkscreen.

Other output frequencies 
For other output frequencies, the filter will tune from around 400MHz upto about 700MHz. For lower output frequencies increase the 3.3nH inductor, e.g. to 3.9nH. For higher frequencies reduce it. The tuning is fairly sharp so take your time and do not under any circumstances even consider using a metal screwdriver to tune it up.

Other input frequencies 
There is no reason to be limited to 50-70MHz. This will work at 2m too but the input filter will need to be modified, ideally to a band pass to keep out the broadcast band. The board had been designed to allow several different filter topologies.

Modamp 
You do not have to use a PGA-103+. Other similar devices like the SPF5189z will work. If you already have a pre-amplifier with sufficient gain, say 20dB or more, the modamp can be bypassed and there is no need for a power supply or regulator.

Impact of inductor Q 

Not all SMD inductors are of the same quality factor (Q). For filters it is important to use high Q components, otherwise the filter will be lossy and may not have the expected performance. The two 3.3nH inductors in the output filter are probably the most critical, parts are preferred with a Q of 30 or more and will result in a filter loss of 4-5dB. Not great, but a fair compromise. If you use low Q inductors, (some cheaper ones are as low as 10), it will work, but the output filter will have more loss.

Good inductor Q = 38, e.g. AVX L08053R3DEWTR or Coilcraft 0805CS-030XJLC
 

[[File:BPFQ38.jpg|400px]]
 
Moderate inductor Q = 16
 
[[File:BPFQ16.jpg|400px]]
 
Awful inductor Q = 10
 
[[File:BPFQ10.jpg|400px]]

[https://youtu.be/D9r-Zb_YhsU A video of an upconverter in action by David M0YDH is here.]

THis picture shows a later upconverter system built by M0YDH. Clockwise from bottom right:- 12V in and 5V regulated supply // BATC PIC card with program for 400MHz to control the sysnthesiser // ADF4351 synthesiser as LO // EBay 400- 470 MHz low pass filter // SPF5189Z amp // G0MJW upconverter card with -6dB attenuation// pair of G0MJW RF SPDT relay boards / The Normally Closed bypass line in SMA fittings. One switch on the unit front panel when turned on energises the upconverter. The other side of the plain PCB card has a Minitioune v1.5 mounted on it.

[[File:M0YDH Upconverter.jpg|600px]]

===Antennas===
Before buying or building a beam here are two low cost designs to get you onto the band

1) [https://sites.google.com/site/gw7aav/main-index/antenna-index/antenna-design/4m-delta Delta Loop by Steve GW7AAV]. David M0YDH made one of these some years ago for SOTA and it was a VSWR approaching 1:1 straight away. Old TV coax is used for the matching section. Electrical conduit is used for the boom [not flimsy waste water pipe!]. You could fasten two mini telescopic masts to a plastic bread board with pipe clamps to support the wire triangle. There is a 6m version on the site too.

2)[http://www.70mhz.org/coaxdipole.htm A centre-fed "co-axial" dipole for 4m by Tony G4CJZ] was built quickly be Noel G8GTZ with acceptable results to get on the band.

===Filters===
These are in the [[70MHz_filters|Filters section of this Wiki]].

Portsdown 2018

2022-08-12T13:31:57Z

M0YDH: /* Portsdown 2018 User guide */

The Portsdown 2018 DATV system has been designed to provide an easy way to “get on air” with Digital ATV at a relatively low cost, covering all of the commonly used modes, thus enabling it to be used not only on ATV repeaters but also for RB-TV Dx working.

The filter modulator card and DATVExpress card described on these pages are no longer available and new builders should follow the [[Portsdown 2020|Portsdown 2020 build instructions here]].

At end of 2018 the decision was taken not to get any more FM boards assembled as demand had dropped significantly and as we had to buy a minimum quantity of 60 we risked losing a lot of members money - all this was posted on the forum back in November and in CQ-TV 262 https://forum.batc.org.uk/viewtopic.php?f=88&t=5760.

Please note there is NO intention to discontinue support of the 2018 system. Portsdown 2020 is recommended for all new builds but if you would still like an F-M board, we suggest you post on the wanted section of the forum - https://forum.batc.org.uk/viewforum.php?f=14 - or blank PCBs for home construction are still available here - [https://batc.org.uk/shop/portsdown-transmitter-filter-modulator-board-blank-pcb/ BATC shop item 10]. Once a stable installation has been built, Portsdown 2018 works reliably - no trouble nor reboots like the later SDRs - so is excellent for local DATV and shack tests.

===Portsdown 2018 User guide===

This user guide is in a number of sections which cover detailed descriptions for hardware and software, how to build and configure the system, some advanced features and an FAQ.

[[File:KLB portsdown (1).JPG|400px|center]]

G4KLB's Portsdown 2018 was the example that many new builders copied when the project started but the case shown is too small to comfortably fit in the modules in the system.

This old index page covers most of the Portsdown 2018 features: [[The Portsdown Transmitter index]]

===System specification===
*[[Portsdown Output Levels|Transmitter specifications]] Frequency range, MER and Output Levels to be expected on each band.

===Building the system===
*[[Portsdown hardware]] Detailed description of the Portsdown hardware and a '''shopping list of what you need to buy and where to buy it'''.
*[[Assembling Portsdown|Assembling your Portsdown]] How to put all the hardware together - '''you need to read this!'''
*[[Portsdown Displays]] Advice on what display to use with your Portsdown transmitter.

===Portsdown Software===
The software has recently undergone a major update. If you are building a new system, or upgrading one built since March 2018, please refer to the Portsdown 2018 Stretch software guide. The original Portsdown (Jessie) software has also been upgraded to Portsdown 2018 standard.
*[[Portsdown 2018 Stretch Software|Portsdown 2018/2019 Stretch Software]] The latest and greatest software for the Portsdown and how to get a programmed SD card.
*[[Portsdown software|Portsdown Jessie Software]] Detailed description of the older Portsdown software.
*[[Software capabilities and issues]] An up to date list is available here
*[[Updating your Portsdown Software]] How to update your Portsdown software to the latest version, with suggestions for troubleshooting updates.

===Configuring and controlling the system===

The Portsdown software is now pre-configured to use the Waveshare touchscreen. If you are using this screen, no initial set-up is required.

For advanced set-up, or if you do not have a Waveshare touchscreen, See this guide: [[Initial setup 2019]]

You can control the Portsdown transmitter in one of 2 modes: by the use of the touchscreen or through the console using a second computer.

*[[Touchscreen mode]] How to use your Portsdown transmitter using the Touchscreen LCD only
*[[Console mode]] Use this mode to configure your Portsdown and change pre-set configs (such as SR and Freq) used in touch screen buttons.
*[[Changing system setup]] How to change Portsdown transmitter settings when in Touchscreen mode
*[[QPSKRF or Ugly mode]] Notes on this special test mode and the limitations when using it
*[[Setting up the WiFi]] How to set up the WiFi on the RPi3 Portsdown Transmitter

===Advanced features===
The Portsdown is not just a DATV transmitter but has several advanced features which are or may be available in the future:

*[[Lean DVB receiver]] How to use the integrated RTL SDR based monitoring receiver - this is NOT the Portsdown receiver
*[[Streaming_to_batc.tv_with_Raspberry_Pi| Streaming to the BATC Streamer]] How to use your Portsdown transmitter as a standalone streamer
*[[Controlling a DATVExpress]] How to use a Portsdown as a user interface for DATV Express
*[[Use With a DTX-1]] How to use your Portsdown transmitter to transmit RB-TV with a DTX-1
*[[Feeding Video to Portsdown from vMix]] How to use vMix with your Portsdown transmitter
*[[Analog Video Output]] How to use your Portsdown as an Analog PAL Video Source
*[[Still Capture from Composite Video Input]] How to capture still images from a Composite Video input.
*[[Hardware-only Transmit Switching]] How to use the Portsdown without a Touchscreen or computer.
*[[Portsdown Signal Generator]]
*[[Calibrating the TouchScreen Alignment]]
*[[FreqShow]] Displaying the received frequency spectrum
*[[Portsdown_Webcams|How to Use Webcams with the Portsdown]]
*[[RTL-FM Receiver|An Integrated RTL-FM Audio Receiver]]

===On line support / social media===

There is a Portsdown area on the BATC forum where the BATC core team and wider ATV community will answer your questions and posting results of the latest builds and on air tests. https://forum.batc.org.uk/viewforum.php?f=103

Note that the BATC core team do not regularly visit Facebook pages - time is just too short to monitor everything and it's not easy to follow threads on Facebook. If you need a question answered please post on the BATC forums first.

===Additional information===

Filters and driver amplifiers are not part of the Portsdown project but VERY important

* [[Filters]]
* [[Power_amplifiers]]

The Portsdown user's community including a map showing where user locations

* [[Portsdown community]]

An index of all Portsdown pages

* [[The Portsdown Transmitter index]]

You may also find this index of TLAs useful when reading the manual!
*[[Glossary_of_terms]]

===Portsdown transmitter FAQ===

And of course we need an FAQ page for those people who don't read the manual!
*[[Portsdown transmitter FAQ]]

Portsdown 2018

2022-08-12T13:29:31Z

M0YDH: P2018 works reliably

The Portsdown 2018 DATV system has been designed to provide an easy way to “get on air” with Digital ATV at a relatively low cost, covering all of the commonly used modes, thus enabling it to be used not only on ATV repeaters but also for RB-TV Dx working.

The filter modulator card and DATVExpress card described on these pages are no longer available and new builders should follow the [[Portsdown 2020|Portsdown 2020 build instructions here]].

At end of 2018 the decision was taken not to get any more FM boards assembled as demand had dropped significantly and as we had to buy a minimum quantity of 60 we risked losing a lot of members money - all this was posted on the forum back in November and in CQ-TV 262 https://forum.batc.org.uk/viewtopic.php?f=88&t=5760.

Please note there is NO intention to discontinue support of the 2018 system. Portsdown 2020 is recommended for all new builds but if you would still like an F-M board, we suggest you post on the wanted section of the forum - https://forum.batc.org.uk/viewforum.php?f=14 - or blank PCBs for home construction are still available here - [https://batc.org.uk/shop/portsdown-transmitter-filter-modulator-board-blank-pcb/ BATC shop item 10]. Once a stable installation has been built, Portsdown 2018 works reliably - no trouble nor reboots like the later SDRs - so is excellent for local DATV and shack tests.

===Portsdown 2018 User guide===

This user guide is in a number of sections which cover detailed descriptions for hardware and software, how to build and configure the system, some advanced features and an FAQ.

[[File:KLB portsdown (1).JPG|400px|center]]

This old index page covers most of the Portsdown 2018 features: [[The Portsdown Transmitter index]]

===System specification===
*[[Portsdown Output Levels|Transmitter specifications]] Frequency range, MER and Output Levels to be expected on each band.

===Building the system===
*[[Portsdown hardware]] Detailed description of the Portsdown hardware and a '''shopping list of what you need to buy and where to buy it'''.
*[[Assembling Portsdown|Assembling your Portsdown]] How to put all the hardware together - '''you need to read this!'''
*[[Portsdown Displays]] Advice on what display to use with your Portsdown transmitter.

===Portsdown Software===
The software has recently undergone a major update. If you are building a new system, or upgrading one built since March 2018, please refer to the Portsdown 2018 Stretch software guide. The original Portsdown (Jessie) software has also been upgraded to Portsdown 2018 standard.
*[[Portsdown 2018 Stretch Software|Portsdown 2018/2019 Stretch Software]] The latest and greatest software for the Portsdown and how to get a programmed SD card.
*[[Portsdown software|Portsdown Jessie Software]] Detailed description of the older Portsdown software.
*[[Software capabilities and issues]] An up to date list is available here
*[[Updating your Portsdown Software]] How to update your Portsdown software to the latest version, with suggestions for troubleshooting updates.

===Configuring and controlling the system===

The Portsdown software is now pre-configured to use the Waveshare touchscreen. If you are using this screen, no initial set-up is required.

For advanced set-up, or if you do not have a Waveshare touchscreen, See this guide: [[Initial setup 2019]]

You can control the Portsdown transmitter in one of 2 modes: by the use of the touchscreen or through the console using a second computer.

*[[Touchscreen mode]] How to use your Portsdown transmitter using the Touchscreen LCD only
*[[Console mode]] Use this mode to configure your Portsdown and change pre-set configs (such as SR and Freq) used in touch screen buttons.
*[[Changing system setup]] How to change Portsdown transmitter settings when in Touchscreen mode
*[[QPSKRF or Ugly mode]] Notes on this special test mode and the limitations when using it
*[[Setting up the WiFi]] How to set up the WiFi on the RPi3 Portsdown Transmitter

===Advanced features===
The Portsdown is not just a DATV transmitter but has several advanced features which are or may be available in the future:

*[[Lean DVB receiver]] How to use the integrated RTL SDR based monitoring receiver - this is NOT the Portsdown receiver
*[[Streaming_to_batc.tv_with_Raspberry_Pi| Streaming to the BATC Streamer]] How to use your Portsdown transmitter as a standalone streamer
*[[Controlling a DATVExpress]] How to use a Portsdown as a user interface for DATV Express
*[[Use With a DTX-1]] How to use your Portsdown transmitter to transmit RB-TV with a DTX-1
*[[Feeding Video to Portsdown from vMix]] How to use vMix with your Portsdown transmitter
*[[Analog Video Output]] How to use your Portsdown as an Analog PAL Video Source
*[[Still Capture from Composite Video Input]] How to capture still images from a Composite Video input.
*[[Hardware-only Transmit Switching]] How to use the Portsdown without a Touchscreen or computer.
*[[Portsdown Signal Generator]]
*[[Calibrating the TouchScreen Alignment]]
*[[FreqShow]] Displaying the received frequency spectrum
*[[Portsdown_Webcams|How to Use Webcams with the Portsdown]]
*[[RTL-FM Receiver|An Integrated RTL-FM Audio Receiver]]

===On line support / social media===

There is a Portsdown area on the BATC forum where the BATC core team and wider ATV community will answer your questions and posting results of the latest builds and on air tests. https://forum.batc.org.uk/viewforum.php?f=103

Note that the BATC core team do not regularly visit Facebook pages - time is just too short to monitor everything and it's not easy to follow threads on Facebook. If you need a question answered please post on the BATC forums first.

===Additional information===

Filters and driver amplifiers are not part of the Portsdown project but VERY important

* [[Filters]]
* [[Power_amplifiers]]

The Portsdown user's community including a map showing where user locations

* [[Portsdown community]]

An index of all Portsdown pages

* [[The Portsdown Transmitter index]]

You may also find this index of TLAs useful when reading the manual!
*[[Glossary_of_terms]]

===Portsdown transmitter FAQ===

And of course we need an FAQ page for those people who don't read the manual!
*[[Portsdown transmitter FAQ]]

Assembling Portsdown

2022-08-12T13:21:56Z

M0YDH: /* Mechanical Design */

This section will describe in detail how to assemble your Portsdown transmitter - to begin, you need to have bought or built all the components listed in the [[Portsdown hardware|hardware description.]]

This page describes how to build the complete transmitter assembly but you can run the Portsdown as an experiment in [[QPSKRF or Ugly mode|"Ugly Mode"]], currently labelled in the Menu as QPSKRF. That does not require you to wire anything together.

===Mechanical Design===

First of all, decide on your mechanical design. You are going to need to have the RPi firmly mounted, with the Micro-SD card slot accessible (to change the card if required) and the power, network and USB connectors available. Then you will need to stack a GPIO extender on top of the RPi. A secondhand 3U 19" rack case with mounting rails for vertical circuit cards may well be a good value purchase that is tall enough to take the 7 inch screen if you upgrade to Portsdown 2020 [Portsdown 3] later on. There will be enough room in this for a Minitioune receiver, 71MHz upconverter, all of the Portsdown 2018 hardware, a Lime Mini SDR, voltage converters and maybe some switch gear for amps.

The most difficult part will be to mount the Touchscreen display. It can either be stacked on top of the RPi, or you can connect it by a short multiway lead and mount it on the front panel of your housing - an example is here: http://www.ebay.co.uk/itm/141354697688

f you have a 3D printer you could try make up one of these housing http://www.thingiverse.com/thing:1920486

You will then need to consider mounting the ADF4351 Synthesizer, any LO filters and then the Filter/modulator board. Other things to think about might be a 5V power supply, a relay/PTT switching board and any dongles (EasyCap, Sound or RTL-SDR).

The block diagram of what you are trying to achieve is below. Note that you will need an additional filter between the synthesizer and the filter/modulator board for 437 MHz and 146 MHz. It is not required for 1255 MHz, and the unit will work on the other bands for testing without it.

[[File:1-1 Block Diagram.jpg|600px]]

An example layout is here

[[File:In the box.jpg|600px]]

All the circuit cards for Portsdown 2018 except band decode and GPIO Breakout can be mounted on M3 stand-offs on both sides of a rectangle of plain PCB. A housing for a 25 way D connector can be constructed and soldered on. This has sufficient connections to take all the wiring across to the GPIO Breakout. RG402 semi-rigid coax and SMA fittings have been used with Molex KK connectors for the wiring. Pictures are from M0YDH.

[[File:P2020 M0YDH 03.jpg|600px]] [[File:P2020 M0YDH 04.jpg|600px]]

Here are the Portsdown 2018 cards in a Portsdown 2020 and next to the Pi3 - all in a 3U 19 inch rack case.

[[File:P2020 M0YDH 02.jpg|600px]] [[File:P2020 M0YDH 01.jpg|600px]]

===Interconnecting the modules===

The following diagram shows the interconnects between the various modules - all wire can be non screened (except the Local oscillator feed to the Filter modulator board) but should be kept as short as possible.

[[File:Portsdown interconnects.JPG|600px]]

Higher resolution pdf is available here [[:File:Portsdwon interconnect v2.pdf]]

Or a picture might help...

[[File:assembly.JPG|600px]]

===BATC GPIO breakout card===

The GPIO breakout card is where all the signals and power for Portsdown interconnect and we recommend that you buy the blank PCB from the BATC and make up the breakcard using either connectors or hard wiring to the other boards.
For more details see this [[GPIO breakout|wiki page]]

[[File:screw t.jpg|300px]]

[[Willow components breakout card]] (If you have bought the BATC GPIO breakout card you DO NOT NEED to read this section)

===Powering the ADF4351===

The ADF4351 module needs between 5 and 9 volts on its power connector. You can either buy a suitable (small barrel) connector or solder the wires to the underside of the board. The 5V supply can be taken from the same source as the Raspberry Pi 5.2V supply, or from any other 5V supply. It does not need to be very clean. DO NOT try to put 3.3V into the marked pin on the data connector on the module; this is a low current output, not an input.

===RF Wiring===

Use short flexible SMA cables to connect the ADF4351 (through filters if necessary) to the filter/modulator board. Use another cable to take the output to a panel connector or subsequent filters and power amplifiers.

You may also want to extend the input of any RTL-SDR to be accessible from a panel connector.

===Power Supplies and Wiring===

You should power the RPi through the Micro-USB power connector to take advantage of the input protection provided. Use a very short USB cable to your power supply as most of these cables are of very poor quality and cause significant voltage drop. For best results, cut the USB cable 5cm from the connector and run "real" wiring from there to your power supply.

Do not power unnecessary items from the RPi's 5v outputs on the GPIO connector. Doing so will induce extra voltage drop in the input protection circuitry. Power the VCO filter and RF Switch directly from the switch mode power supply. No problems with ripple have been observed.

A lot of strange problems, such as the Portsdown running very slowly, can be caused by low PSU voltage - the RPi3 supply voltage is actually specified as 5.1 volts, so make sure your PSU delivers enough voltage and is capable of sourcing enough current. See [https://forum.batc.org.uk/viewtopic.php?t=4856&p=11935#p11935 this post on the BATC forum] for a real user experience!

If you see a "Lightning Flash" symbol at the top right of your LCD display it means that the voltage at the RPi is too low. You can measure the voltage between the GPIO connector pins 4 and 6.

[[File:flash.jpg|400px]]

You can check if there are any problems by running the command
vcgencmd get_throttled
from the command line. You should get the response "throttled=0x0" which means that all is well. The response "throttled=0x50000" means that the voltage has dropped below the safe level at least once since boot-up; the response "throttled=0x50005" means that the voltage is currently below the safe level. Other responses might mean that your RPi is overheating. The "Info" screen on Menu 3 will also state if there have been any low-voltage events since boot-up.

An eBay buck regulator capable of supplying at least 4A continuous at 5.2V is recommended to power the RPi, an EasyCap, an RTL-SDR and the ADF4351. '''Consumer-grade RPi power supplies with consumer grade USB cables have rarely proved to be capable of supplying this high demand without causing dropouts.'''

The filter/modulator board needs a clean 5V at 250 mA and the on-board linear regulator supplies this, but can get warm at higher input voltages. The linear regulator needs at least 7V to operate properly. Feeding it with 8 volts provides the best compromise between regulator margin and heat dissipation.

You can use a switching or buck converter to supply the filter-modulator board with 5V, but the switching ripple introduces some detectable sidebands on the transmitted signal. These have very little adverse effect, but are visible on a spectrum analyser. On-board switching regulators have been tested, and the pads are there for L10 to provide extra filtering. Again, they introduce low-level sidebands, but these are probably not significant.

===Network and USB Wiring===

Consider bringing the network connector and one of the USB connectors out to the panel for easy access and mechanical stability.

===Camera Wiring===

The RPi camera gives excellent results, but only comes with a short ribbon cable to connect it to the RPi.

It is possible to use some higher quality HDMI leads (the ground connections all need to be made) to extend the camera lead - this does NOT mean the signal out of the camera is HDMI, it is actually "Camera Serial Interface Type 2 (CSI-2)". We are just using HDMI cable as a useful extension lead. The modification described here https://wiki.batc.org.uk/CSI-2_to_HDMI allows the use of lower quality HDMI cables.

Kits are available to connect a female HDMI connector to the RPi camera connector, and another female to the camera, allowing the use of domestic 1, 2 and 3m HDMI leads. The Pi camera HDMI Lead Extension Kit is available from here https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

===USB Cables===

Use short (shortened?) good quality USB cables to connect the EasyCap and RTL-SDR to the RPi. Use of the poor-quality USB cable supplied with the EasyCap has been shown to cause audio dropouts in a streamed signal.

Assembling Portsdown

2022-08-12T13:20:25Z

M0YDH: /* Mechanical Design */ P2018 on 2 sides of a PCB

This section will describe in detail how to assemble your Portsdown transmitter - to begin, you need to have bought or built all the components listed in the [[Portsdown hardware|hardware description.]]

This page describes how to build the complete transmitter assembly but you can run the Portsdown as an experiment in [[QPSKRF or Ugly mode|"Ugly Mode"]], currently labelled in the Menu as QPSKRF. That does not require you to wire anything together.

===Mechanical Design===

First of all, decide on your mechanical design. You are going to need to have the RPi firmly mounted, with the Micro-SD card slot accessible (to change the card if required) and the power, network and USB connectors available. Then you will need to stack a GPIO extender on top of the RPi. A secondhand 3U 19" rack case with mounting rails for vertical circuit cards may well be a good value purchase that is tall enough to take the 7 inch screen if you upgrade to Portsdown 2020 [Portsdown 3] later on. There will be enough room in this for a Minitioune receiver, 71MHz upconverter, all of the Portsdown 2018 hardware, a Lime Mini SDR, voltage converters and maybe some switch gear for amps.

The most difficult part will be to mount the Touchscreen display. It can either be stacked on top of the RPi, or you can connect it by a short multiway lead and mount it on the front panel of your housing - an example is here: http://www.ebay.co.uk/itm/141354697688

f you have a 3D printer you could try make up one of these housing http://www.thingiverse.com/thing:1920486

You will then need to consider mounting the ADF4351 Synthesizer, any LO filters and then the Filter/modulator board. Other things to think about might be a 5V power supply, a relay/PTT switching board and any dongles (EasyCap, Sound or RTL-SDR).

The block diagram of what you are trying to achieve is below. Note that you will need an additional filter between the synthesizer and the filter/modulator board for 437 MHz and 146 MHz. It is not required for 1255 MHz, and the unit will work on the other bands for testing without it.

[[File:1-1 Block Diagram.jpg|600px]]

An example layout is here

[[File:In the box.jpg|600px]]

All the circuit cards for Portsdown 2018 except band decode and GPIO Breakout can be mounted on M3 stand-offs on both sides of a rectangle of plain PCB. A housing for a 25 way D connector can be constructed and soldered on. This has sufficient connections to take all the wiring across to the GPIO Breakout. RG402 semi-rigid coax and SMA fittings have been used with Molex KK connectors for the wiring. Pictures are from M0YDH.

[[File:P2020 M0YDH 03.jpg|600px]] [[File:P2020 M0YDH 04.jpg|600px]]

Here are the Portsdown 2018 cards in a Portsdown 2020 and next to the Pi3 - all in a 3U 19 inch rack case.

[[File:P2020 M0YDH 02.jpg|600px]]

===Interconnecting the modules===

The following diagram shows the interconnects between the various modules - all wire can be non screened (except the Local oscillator feed to the Filter modulator board) but should be kept as short as possible.

[[File:Portsdown interconnects.JPG|600px]]

Higher resolution pdf is available here [[:File:Portsdwon interconnect v2.pdf]]

Or a picture might help...

[[File:assembly.JPG|600px]]

===BATC GPIO breakout card===

The GPIO breakout card is where all the signals and power for Portsdown interconnect and we recommend that you buy the blank PCB from the BATC and make up the breakcard using either connectors or hard wiring to the other boards.
For more details see this [[GPIO breakout|wiki page]]

[[File:screw t.jpg|300px]]

[[Willow components breakout card]] (If you have bought the BATC GPIO breakout card you DO NOT NEED to read this section)

===Powering the ADF4351===

The ADF4351 module needs between 5 and 9 volts on its power connector. You can either buy a suitable (small barrel) connector or solder the wires to the underside of the board. The 5V supply can be taken from the same source as the Raspberry Pi 5.2V supply, or from any other 5V supply. It does not need to be very clean. DO NOT try to put 3.3V into the marked pin on the data connector on the module; this is a low current output, not an input.

===RF Wiring===

Use short flexible SMA cables to connect the ADF4351 (through filters if necessary) to the filter/modulator board. Use another cable to take the output to a panel connector or subsequent filters and power amplifiers.

You may also want to extend the input of any RTL-SDR to be accessible from a panel connector.

===Power Supplies and Wiring===

You should power the RPi through the Micro-USB power connector to take advantage of the input protection provided. Use a very short USB cable to your power supply as most of these cables are of very poor quality and cause significant voltage drop. For best results, cut the USB cable 5cm from the connector and run "real" wiring from there to your power supply.

Do not power unnecessary items from the RPi's 5v outputs on the GPIO connector. Doing so will induce extra voltage drop in the input protection circuitry. Power the VCO filter and RF Switch directly from the switch mode power supply. No problems with ripple have been observed.

A lot of strange problems, such as the Portsdown running very slowly, can be caused by low PSU voltage - the RPi3 supply voltage is actually specified as 5.1 volts, so make sure your PSU delivers enough voltage and is capable of sourcing enough current. See [https://forum.batc.org.uk/viewtopic.php?t=4856&p=11935#p11935 this post on the BATC forum] for a real user experience!

If you see a "Lightning Flash" symbol at the top right of your LCD display it means that the voltage at the RPi is too low. You can measure the voltage between the GPIO connector pins 4 and 6.

[[File:flash.jpg|400px]]

You can check if there are any problems by running the command
vcgencmd get_throttled
from the command line. You should get the response "throttled=0x0" which means that all is well. The response "throttled=0x50000" means that the voltage has dropped below the safe level at least once since boot-up; the response "throttled=0x50005" means that the voltage is currently below the safe level. Other responses might mean that your RPi is overheating. The "Info" screen on Menu 3 will also state if there have been any low-voltage events since boot-up.

An eBay buck regulator capable of supplying at least 4A continuous at 5.2V is recommended to power the RPi, an EasyCap, an RTL-SDR and the ADF4351. '''Consumer-grade RPi power supplies with consumer grade USB cables have rarely proved to be capable of supplying this high demand without causing dropouts.'''

The filter/modulator board needs a clean 5V at 250 mA and the on-board linear regulator supplies this, but can get warm at higher input voltages. The linear regulator needs at least 7V to operate properly. Feeding it with 8 volts provides the best compromise between regulator margin and heat dissipation.

You can use a switching or buck converter to supply the filter-modulator board with 5V, but the switching ripple introduces some detectable sidebands on the transmitted signal. These have very little adverse effect, but are visible on a spectrum analyser. On-board switching regulators have been tested, and the pads are there for L10 to provide extra filtering. Again, they introduce low-level sidebands, but these are probably not significant.

===Network and USB Wiring===

Consider bringing the network connector and one of the USB connectors out to the panel for easy access and mechanical stability.

===Camera Wiring===

The RPi camera gives excellent results, but only comes with a short ribbon cable to connect it to the RPi.

It is possible to use some higher quality HDMI leads (the ground connections all need to be made) to extend the camera lead - this does NOT mean the signal out of the camera is HDMI, it is actually "Camera Serial Interface Type 2 (CSI-2)". We are just using HDMI cable as a useful extension lead. The modification described here https://wiki.batc.org.uk/CSI-2_to_HDMI allows the use of lower quality HDMI cables.

Kits are available to connect a female HDMI connector to the RPi camera connector, and another female to the camera, allowing the use of domestic 1, 2 and 3m HDMI leads. The Pi camera HDMI Lead Extension Kit is available from here https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

===USB Cables===

Use short (shortened?) good quality USB cables to connect the EasyCap and RTL-SDR to the RPi. Use of the poor-quality USB cable supplied with the EasyCap has been shown to cause audio dropouts in a streamed signal.

Assembling Portsdown

2022-08-12T13:01:25Z

M0YDH: /* Mechanical Design */ 3U 19 inch rack case

This section will describe in detail how to assemble your Portsdown transmitter - to begin, you need to have bought or built all the components listed in the [[Portsdown hardware|hardware description.]]

This page describes how to build the complete transmitter assembly but you can run the Portsdown as an experiment in [[QPSKRF or Ugly mode|"Ugly Mode"]], currently labelled in the Menu as QPSKRF. That does not require you to wire anything together.

===Mechanical Design===

First of all, decide on your mechanical design. You are going to need to have the RPi firmly mounted, with the Micro-SD card slot accessible (to change the card if required) and the power, network and USB connectors available. Then you will need to stack a GPIO extender on top of the RPi. A secondhand 3U 19" rack case with mounting rails for vertical circuit cards may well be a good value purchase that is tall enough to take the 7 inch screen if you upgrade to Portsdown 2020 [Portsdown 3] later on. There will be enough room in this for a Minitioune receiver, 71MHz upconverter, all of the Portsdown 2018 hardware, a Lime Mini SDR, voltage converters and maybe some switch gear for amps.

The most difficult part will be to mount the Touchscreen display. It can either be stacked on top of the RPi, or you can connect it by a short multiway lead and mount it on the front panel of your housing - an example is here: http://www.ebay.co.uk/itm/141354697688

f you have a 3D printer you could try make up one of these housing http://www.thingiverse.com/thing:1920486

You will then need to consider mounting the ADF4351 Synthesizer, any LO filters and then the Filter/modulator board. Other things to think about might be a 5V power supply, a relay/PTT switching board and any dongles (EasyCap, Sound or RTL-SDR).

The block diagram of what you are trying to achieve is below. Note that you will need an additional filter between the synthesizer and the filter/modulator board for 437 MHz and 146 MHz. It is not required for 1255 MHz, and the unit will work on the other bands for testing without it.

[[File:1-1 Block Diagram.jpg|600px]]

An example layout is here

[[File:In the box.jpg|600px]]

===Interconnecting the modules===

The following diagram shows the interconnects between the various modules - all wire can be non screened (except the Local oscillator feed to the Filter modulator board) but should be kept as short as possible.

[[File:Portsdown interconnects.JPG|600px]]

Higher resolution pdf is available here [[:File:Portsdwon interconnect v2.pdf]]

Or a picture might help...

[[File:assembly.JPG|600px]]

===BATC GPIO breakout card===

The GPIO breakout card is where all the signals and power for Portsdown interconnect and we recommend that you buy the blank PCB from the BATC and make up the breakcard using either connectors or hard wiring to the other boards.
For more details see this [[GPIO breakout|wiki page]]

[[File:screw t.jpg|300px]]

[[Willow components breakout card]] (If you have bought the BATC GPIO breakout card you DO NOT NEED to read this section)

===Powering the ADF4351===

The ADF4351 module needs between 5 and 9 volts on its power connector. You can either buy a suitable (small barrel) connector or solder the wires to the underside of the board. The 5V supply can be taken from the same source as the Raspberry Pi 5.2V supply, or from any other 5V supply. It does not need to be very clean. DO NOT try to put 3.3V into the marked pin on the data connector on the module; this is a low current output, not an input.

===RF Wiring===

Use short flexible SMA cables to connect the ADF4351 (through filters if necessary) to the filter/modulator board. Use another cable to take the output to a panel connector or subsequent filters and power amplifiers.

You may also want to extend the input of any RTL-SDR to be accessible from a panel connector.

===Power Supplies and Wiring===

You should power the RPi through the Micro-USB power connector to take advantage of the input protection provided. Use a very short USB cable to your power supply as most of these cables are of very poor quality and cause significant voltage drop. For best results, cut the USB cable 5cm from the connector and run "real" wiring from there to your power supply.

Do not power unnecessary items from the RPi's 5v outputs on the GPIO connector. Doing so will induce extra voltage drop in the input protection circuitry. Power the VCO filter and RF Switch directly from the switch mode power supply. No problems with ripple have been observed.

A lot of strange problems, such as the Portsdown running very slowly, can be caused by low PSU voltage - the RPi3 supply voltage is actually specified as 5.1 volts, so make sure your PSU delivers enough voltage and is capable of sourcing enough current. See [https://forum.batc.org.uk/viewtopic.php?t=4856&p=11935#p11935 this post on the BATC forum] for a real user experience!

If you see a "Lightning Flash" symbol at the top right of your LCD display it means that the voltage at the RPi is too low. You can measure the voltage between the GPIO connector pins 4 and 6.

[[File:flash.jpg|400px]]

You can check if there are any problems by running the command
vcgencmd get_throttled
from the command line. You should get the response "throttled=0x0" which means that all is well. The response "throttled=0x50000" means that the voltage has dropped below the safe level at least once since boot-up; the response "throttled=0x50005" means that the voltage is currently below the safe level. Other responses might mean that your RPi is overheating. The "Info" screen on Menu 3 will also state if there have been any low-voltage events since boot-up.

An eBay buck regulator capable of supplying at least 4A continuous at 5.2V is recommended to power the RPi, an EasyCap, an RTL-SDR and the ADF4351. '''Consumer-grade RPi power supplies with consumer grade USB cables have rarely proved to be capable of supplying this high demand without causing dropouts.'''

The filter/modulator board needs a clean 5V at 250 mA and the on-board linear regulator supplies this, but can get warm at higher input voltages. The linear regulator needs at least 7V to operate properly. Feeding it with 8 volts provides the best compromise between regulator margin and heat dissipation.

You can use a switching or buck converter to supply the filter-modulator board with 5V, but the switching ripple introduces some detectable sidebands on the transmitted signal. These have very little adverse effect, but are visible on a spectrum analyser. On-board switching regulators have been tested, and the pads are there for L10 to provide extra filtering. Again, they introduce low-level sidebands, but these are probably not significant.

===Network and USB Wiring===

Consider bringing the network connector and one of the USB connectors out to the panel for easy access and mechanical stability.

===Camera Wiring===

The RPi camera gives excellent results, but only comes with a short ribbon cable to connect it to the RPi.

It is possible to use some higher quality HDMI leads (the ground connections all need to be made) to extend the camera lead - this does NOT mean the signal out of the camera is HDMI, it is actually "Camera Serial Interface Type 2 (CSI-2)". We are just using HDMI cable as a useful extension lead. The modification described here https://wiki.batc.org.uk/CSI-2_to_HDMI allows the use of lower quality HDMI cables.

Kits are available to connect a female HDMI connector to the RPi camera connector, and another female to the camera, allowing the use of domestic 1, 2 and 3m HDMI leads. The Pi camera HDMI Lead Extension Kit is available from here https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/

===USB Cables===

Use short (shortened?) good quality USB cables to connect the EasyCap and RTL-SDR to the RPi. Use of the poor-quality USB cable supplied with the EasyCap has been shown to cause audio dropouts in a streamed signal.