BATC Wiki - User contributions [en-gb]

Getting Started

2018-09-23T18:52:47Z

G6jyb:

Amateur Television is a fascinating area of Amateur Radio covering all aspects of video production, editing, transmission and reception of Television and has always been at the fore front of the technology revolution. Many stations are now transmitting Digital pictures (DATV) using the DVB broadcast standards and using video streaming technologies to exchange pictures with ATV operators around the world.

You're probably here because you want to know more about Amateur Television and so help you get to grips with the basics of our hobby, BATC has put together a series of "Getting started" guides.

Once you've read those, you may be wondering if there's an easy way to "get on the air" - if so take a [[5.6 GHz|look at this page]] which shows you how to join in the fun on 5.6GHz ATV for under £20! Or if you are wondering what what DATV equipment you need to buy, so we have put together a [[DATV Equipment Shopping List|DATV shopping list]] to help you decide how to spend your hard earned cash!

===Getting Started - the basics===

A good place to start is by reading the [[Media:GSATV2016.pdf|Getting Started in ATV leaflet]] also available as an [[Media:Getting started with ATV.pdf|article extract]] from CQ-TV, our quarterly newsletter:

Or take a look at this [[Media:Getting started Feb 2018.pdf|introduction to ATV PowerPoint presentation]]

=== Receiving and Transmitting ATV ===

To find out more about receiving and transmitting ATV signals download these "Getting started" guides:

[[Media:Getting Started in DATV reception.pdf|DATV Reception]]

DATV transmission - take a look at the [[The Portsdown Transmitter|BATC Portsdown project]], a simple easy way to get on air with Digital Television.

=== Reduced Bandwidth TV ===

And to find out more about the latest technology called Reduced Bandwidth Digital television (RBTV) take a look at this [[:media:cqtvrbtv.pdf|RB-TV special edition of CQ-TV]].

For more technical details take a look at our getting started guide to RB-TV.
[[Media:Getting Started with RB-TV.pdf|Getting Started with RB-TV]]

=== Video signal basics ===

If you want to know more about the basics of video signals, Brian Summers has written a series of articles for CQ-TV which are available for downloads as part of our "getting started" series.

Part 1-7 available as a single download:
[[Media:Video Fundamentals 1-7.pdf|Video Fundamentals parts 1-7]]

===What next?===

Having read and digested all the information in these getting started guides and want to get on air, the next thing to look at is the BATC [[The Portsdown Transmitter|Portsdown DATV transmitter]] project. There's probably someone building one near you - you can check by looking at the [https://www.google.com/maps/d/u/0/edit?mid=16rtNSaJLvCfc4wsbJ9p3M6pkua4&ll=2.068709435595707%2C0&z=2 Portsdown users map].

And for a receiver take a look at the [[MiniTioune|Minitioune]] project.

Or if you want to get on to ATV the really easy way and for very little cost - take a look at [[5.6 GHz|this page on using the 5.6GHz Drone FPV transmitters]]!

And then head over to the [https://forum.batc.org.uk/ BATC members forum] to gain even more knowledge and ask those questions you must have - and don't worry the ATV community are a friendly bunch!

Or take a look to see if there's a TV repeater near you on [[UK ATV repeaters|this wiki page.]]

70cm DATV

2018-09-23T18:15:54Z

G6jyb:

Activity in the 70cm band is now largely digital - based on DVB-S/S2 QPSK

* Activity Centre: 437 MHz - See the [https://rsgb.org/main/operating/band-plans/ RSGB Band Plan]

* Repeater Inputs: A number of UK repeaters have 437 MHz Rx inputs (with outputs on other bands)

5.6 GHz

2018-09-23T18:11:27Z

G6jyb: /* Frequency choice */

[[File:5.6 GHz Orientation Small.jpg|300px|center]]
It is very easy (and low cost) to get on the air on 5.6GHz (the 6 cm amateur band), using the cheap modules intended to transmit “First Person Video” (FPV) back from drones to their operators. These units can be used without any modifications to get on air, and with simple WiFi plate or dish antennas (and a clear line of sight path) can be used to send pictures to stations using the same equipment over paths in excess of 50km.

M0KPW has an excellent website describing his 5.6GHz system http://www.5-6ghz-atv.co.uk/

==Frequency choice==

The overall UK amateur band plan is shown on the RSGB website here: https://rsgb.org/main/operating/band-plans/. As the UK amateur frequency allocation for 5 GHz is not contiguous spectrum, the RSGB has some [https://rsgb.org/main/operating/band-plans/microwaves/5-7-and-10ghz/ useful guidance] which is adapted below with arrow markers:-

[[File:bandplan.JPG|800px]]

GB3KM has a licensed input on 5665 MHz and this has been chosen as the primary ATV operating frequency. Audio WB-FM operators have been using 5825 and 5840 MHz. 5825 MHz is too close to the band edge for ATV, and 5840 MHz is marginal. So 5665 is the general ATV preference

The FPV equipment receive and transmit frequencies are set using DIP switches, and most tune to 5665 MHz – but care needs to be taken when selecting equipment to make sure it does cover this frequency. Example channel tables are shown at the bottom of this page.

==Equipment==

The FPV units are widely advertised on eBay and other sites with titles similar to “Tarot 5.8G 600MW Telemetry TX/RX Combo for FPV Image Transmission TL300N” and are available at reasonable prices. The typical units are very small but have reasonable FM-TV performance with a quoted transmitter spec of 600mW output and receiver sensitivity of -80dBm. Amplifiers are available to raise the output power to 2 watts or more.

[[File:Tairot 1.jpg|400px]]

Be aware – we have found that on some receiver units, the video output is on the Red phono lead and not the expected Yellow lead!

Some other users' stations are described here [[5.6 GHz Equipment Examples]].

===Improvements to Commercial Units===

In CQ-TV 260, Achille I2GLI described improvements and additions to the Mateksys VTX-HV drone transmitter to make a high quality 18 watt output 5.6 GHz FM transmitter. One of the improvements was to replace the video and sound baseband circuitry. The published circuit diagram in online CQ-TV was a little unclear (although the printed version is good). The circuit diagram is reproduced below.
[[File:BandaBase.jpg|672px]]

===Mounting the equipment===
Due to the very high losses in co-ax cable at 5.6GHz it is recommended that you mount the units very close to the antennas and run long 12V dc, audio and video cables back down to the shack or operating position.

Be aware also, that whilst these units are very small they do run very hot in operation, and it is suggested that you provide a good heatsink for both Tx and Rx – mounting them in a diecast box on the back of their respective antennas is ideal.

[[File:GKQ 5.6v2.JPG|600px]]

Details of G8GKQ's transceiver setup is shown here (receiver unit on left & transmitter with fan on the right)

===Transmit amplifiers===

Whilst the basic units work very well and have been used to transmit over paths of 60km, power amplifiers to boost the 600mW transmitter signal to 2—4 Watts are available from several suppliers on eBay and other sites, and will significantly increase the path length that the units will work over. These amplifiers should be connected after the transmit unit, but before any antenna change over relay(s) – and remember that his will increase the volt drop on any long 12V cable feeding the transmitter at the masthead.

Be warned!! Several users have found these PAs to be "fragile", so you should always make sure that the antenna is connected – and all connectors done up tight – before applying dc or RF power. We are investigating whether they can be made more reliable by reducing the volts / input drive.

[[File:56PA.jpg|200px]]

==Antenna changeover relays==

The FPV equipment comes as separate Tx and Rx units. In order to operate on a single antenna, you will need an antenna changeover relay. Note, however, that the losses at 5.6GHz can be significant and care must be taken when wiring up the units to ensure RF cables are of good quality, and kept to a minimum length – semi-rigid cables fitted with SMA connectors are ideal.

PL259 and even BNC connectors are very lossy at 5.6GHz and should not be used, but the surplus SMA relays often available at rallys are ideal for 5.6 GHz.

See [[Antennae changeover relays|this wiki page]] for more details on suitable relays, 24 volt operation, and 4 port (or transfer) relays.

If no suitable relay is available, it may be cheaper to use separate antennas for receive and transmit as shown in the picture below – note the Tx and Rx units are mounted directly on the back of the flat panel antennas.

[[File:562.jpg|200px]]

===Reverse SMA===

Be aware that all the 5.6GHz FPV units use "reverse SMA" connectors (as used on WiFi equipment) and that all low-loss cables (unless bought specifically for the purpose) and surplus SMA relays will almost certainly have standard SMA connectors – which will not fit. Adapters from reverse to standard SMA are available on eBay or other suppliers – search for "RP-SMA to SMA adaptor" or similar wording.

==Antennas==

As 5.8GHz is used by broadband wireless networks, there is a wide choice of antennas available for use on 5.6GHz ATV. These can range from flat plates/panels to wire mesh (grid) dishes, as seen in the above pictures.

Horizontal polarisation has been chosen as the standard (waveguide feeds needs to have the long dimension of the aperture – and/or horn – vertically oriented when feeding dishes)

=== Satellite dishes ===

It is also possible to use a satellite mini dish with a suitable feed, such as a waveguide/horn to the design by G4NNS – see here for construction details: http://myweb.tiscali.co.uk/g4nns/FeedHorn.html

The picture shows a Sky mini dish fed with a WA5VJB log-periodic PCB feed http://www.wa5vjb.com/products1.html – these are available in the UK from G4DDK. http://www.g4ddk.com/Prices.html

Dishes of this size typically have a beam width of 4—8 degrees.

[[File:56 dish feed.JPG|400px]]

M1BKF found a very interesting 5.6GHz feed for standard f/d ratio satellite dishes; it contains what looks like a PCB yagi, and is available from:

<s>http://www.antennas-amplifiers.com/5.1-5.5-5.8GHz-WLAN-WiFi-Antenna/Feed-Illuminator-satellite-offset-dish-fd-0.5-0.8</s>

https://www.antennas-amplifiers.com/feed-Illuminator-satellite-offset-dish-fd-0.5-0.8

[[File:PCB dish feed.JPG|200px]] [[File:PCB dish feed2.JPG|300px]]

=== DIY BiQuad antennae ===

This web page http://buildyourownantenna.blogspot.co.uk/2014/07/double-biquad-sector-antenna-for-5-ghz-wifi.html has a well engineered double BiQuad antenna with a quoted 13dBi gain.

Note in the picture G8JAN has directly connected the Tx module to the antenna to avoid co-ax losses.

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

==Video equipment - Rx==
The receiver output will need to be directly connected to a monitor with a composite video input to view the received the signal – normally on a yellow phono or RCA connector.

===Video squelch defeat===

Beware of using modern flat-screen monitors which have a video squelch – these will not display noisy signals, and just give a blue screen until they get a strong video signal.

There are a number of circuits around to defeat the squelch and also improve the readability of the signal.

===Syncsmurf by PE1RQM=== – kits are available; details on the [https://translate.google.com/translate?hl=auto&sl=auto&tl=en-US&u=https%3A%2F%2Fwww.pe1rqm.nl%2Fsyncsmurf2%2F webpage here].

[[File:syncsmurf1.jpg|200px]]

Results are very impressive:

[[File:syncsmurf2.jpg|400px]]

===eachine FPV recorder===

Several people have reported that they are using these devices, available from various sites, and as well as defeating the monitor blue screen by inserting syncs on noise they have a single push button record facility. They record to an SD card which can be removed and the files viewed on a PC; users report that you need to use a good quality SD card, and that they have had problems with Kingston branded cards – Sandisk are preferred.

[[File:emachine dvr.JPG|300px]]

===Video sync processor===

[[File:cqtv 129.jpg|300px]]

Or any video sync processor may be usable such as the Advanced Converter Enhancer used by many stations on 23cms FM TV transmissions.

[[File:ACE.jpg|300px]]

==Video equipment - Tx==
An old camcorder with a yellow phono "video out" socket is an ideal video and audio source for the transmitter.

Don't forget that you will need to display your call sign to remain legal. This can be a video generator, a .jpg card reader with video out, or a piece of card with your call sign scribbled on it!

===Media card reader===

A simple way to generate test patterns is to use a media card reader loaded with .jpg files – these are available on several sites, just search for "SD card media AV player" – but make sure you get one which outputs PAL video.

[[File:av player.JPG|200px]]

===PicDream===
The PicDream project uses a single PIC chip and a 4MHz crystal to generate a black and white test pattern – simple but effective – the original project was described in CQ-TV 180 and re-printed in CQ-TV 247.

[[File:Picdream 247.JPG|400px]]

The PIC code is available for download here: batc.org.uk/cq-tv/software/picdream.zip

===PicDream II===
The PicDream II project uses a PIC chip and an AD724 PAL ecnoder chip to generate a colour test pattern with moving insets. The text and colours on the test pattern can be set through it's serial link.

Further information is at https://github.com/F1CJN/PICDREAM-II

===Raspberry Pi - PA3CHM image generator===

CQ-TV 247 published details of a simple RPi-based test card generator by Ernest PA3CHM.

[[File:PA3chm.JPG|400px]]

Full details are on his website: http://www.pa3hcm.nl/?p=248

===Raspberry Pi - Portsdown patterns===
The BATC Portsdown project can be configured to deliver composite video and audio out from the RPi multi-jack plug.

[[File:GKQ July 2017 (Small).JPG|400px]]

This can be test patterns, RPi desktop, or the Portsdown camera and microphone – [[Analog Video Output|see this wiki page for more details]] making the RPi the only piece of video/audio equipment you need to drive the 5.6GHz transmitter.

===Stand alone Raspberry Pi animated test card generator===
This is the stand alone version of the animated test card generator that is part of the Portsdown software
[[RPi Test Card| - see this wiki page for more details]]

==On the air==

Using dish aerials of 30—60cm, line of sight ranges of 80km can easily be achieved.

P5 (noise free) FM ATV pictures have been exchanged over a 138km path using the equipment described on this page – the picture below shows G4CPE/P on Dunstable Downs being received at the Ridgeway, near Didcot, over a slightly obstructed 66km path.

[[File:CPE 5.6GHz.JPG|400px]]

Dunkery Beacon near Minehead, to Cleeve Common near Cheltenham.
The picture shows G8GTZ/P received by G8GKQ/P over the 138km path.

[[File:snap5 small.jpg|400px]]

2018-04-21: The UK "record" for a contact using standard FPV units was increased to 153km between GW3NWR/P at Bylchau, North Wales to M0KPW/P and G0HIK/P at the Kirkstone Pass Inn, Cumbria.

This has since been surpassed.

==FM voice only==

Several stations in the Gloucester and Bolton area are using these units for wideband FM voice only. This is achieved by simply putting high level (1V peak-peak) audio on the yellow video TX phono input – this modulates the main high level carrier with audio rather than video (the two audio phono connectors – red and white – can be ignored). On RX, the yellow phono connector of the receiver is simply connected to a line level input of an audio amplifier.

It is done this way because the two audio subcarriers transmitted by the unit are at a level 20dB lower than that of the main (video)carrier. However, as it is using the same bandwidth Rx and Tx system, performance will be no better than FM video – ideally the 480MHz RX IF would be tapped off in to an SDR or narrow band receiver to give significantly enhanced (+20db?) narrow band performance.

==Activity hot spots==

There is a Google map showing approximate locations of stations thought to be active on 5.6GHz FM – if you are on 5.6GHz, you can add or edit your station: https://www.google.com/maps/d/u/0/edit?mid=1e4keFSFWy6wLUQNF3IT3n6h90eU&ll=52.39133141509076%2C-1.8917942000000494&z=7

Known users include:

*Southern England = G8GKQ, G8GTZ, G0UHY, G8XZD, G4UVZ, G3VPF
*Dunstable area = M0SKM, G4CPE, G0WFT
*North-East = GB3KM, G1LPS, M0DTS
*Cheltenham = G0LGS, M0RKX and G4NZV (using WB audio only)
*Bolton Wireless Club = G4JLG, G6GVI, G8PEF, M0UFC, MW1FGQ (PW “Siren” Article)
*Ludlow, Shropshire = G8XYJ
*Yorkshire = G8BYN
*Norfolk = G4NJJ, G8JAN, G4WVU and M1BKF
*Cumbria - Barrow-in-Furness Radio Club project
*Merseyside - G3NWR

[[File:cpe2.jpg|400px]]

==More information==

Dave G8GKQ did a presentation at the BATC annual convention CAT17 in September 2017 on getting started on 5.6GHz ATV.
*The presentation is available here https://wiki.batc.tv/images/4/42/CAT17_5.6_GHzv2.pdf
*The video of the session is available on the BATC YouTube channel here https://www.youtube.com/watch?v=XJzGNsGmE9Y

==On line support / social media==

There is a thread running on the BATC forum where the ATV community are exchanging ideas and also posting results of the latest on air tests. https://forum.batc.org.uk/viewtopic.php?f=2&t=5026

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.

==Technical information==

===SM201R===
The large RX chip in most units has had the part number removed, however it appears that a lot of receivers use the SM201R module. The spec and pinout are shown below but notice the frequency range of this particular unit does not seem to cover 5665MHz, so make sure the one you buy does!

[[File:sm201r 2.jpg|500px]] [[File:sm201r 3.JPG|200px]]

[[File:sm201r 1.JPG|500px]]

===S meter output===

Looking at the above table, it appears that the RSSI is available on pin 17 of the SM201R and could potentially be used for a signal strength meter to help align the antennas when setting up a QSO.

It also appears that the SM201R uses a 480MHz IF (same as the Comtech) and potentially could be modified with narrower filters to improve RF performance.

====Tx and Rx perfomance====

Initial measurements suggest the TX bandwidth is 25—30MHz.

[[File:5.6GHz spectrum.jpg|500px]]

This accounts for the quoted RX sensitivity at -80dBm which may be improved by an LNA but will ultimately be limited by the RX IF bandwidth.

===Channel Listings===

As mentioned above, the channel settings vary from manufacturer to manufacturer. This table is taken from the Tarot data sheet which uses the SM201R module but does include 5665MHz:

[[File:Tarot_Channels.jpg|603px]]

And this is the table for the Eachine TS835 transmitter:

[[File:Channels_2.jpg|619px]]

This table is from a "Fat Shark" transmitter that does not cover 5665 MHz:

[[File:Fat_Shark.PNG|300px]]

5.6 GHz

2018-09-23T18:10:43Z

G6jyb: /* Frequency choice */ Editorials and updated links

[[File:5.6 GHz Orientation Small.jpg|300px|center]]
It is very easy (and low cost) to get on the air on 5.6GHz (the 6 cm amateur band), using the cheap modules intended to transmit “First Person Video” (FPV) back from drones to their operators. These units can be used without any modifications to get on air, and with simple WiFi plate or dish antennas (and a clear line of sight path) can be used to send pictures to stations using the same equipment over paths in excess of 50km.

M0KPW has an excellent website describing his 5.6GHz system http://www.5-6ghz-atv.co.uk/

==Frequency choice==

The overall UK amateur band plan is shown on the RSGB website here: https://rsgb.org/main/operating/band-plans/. As the UK amateur frequency allocation for 5 GHz is not contiguous spectrum, the RSGB has some [https://rsgb.org/main/operating/band-plans/microwaves/5-7-and-10ghz/ useful guidance] which is adapted below with arrow markers for ATV

[[File:bandplan.JPG|800px]]

GB3KM has a licensed input on 5665 MHz and this has been chosen as the primary ATV operating frequency. Audio WB-FM operators have been using 5825 and 5840 MHz. 5825 MHz is too close to the band edge for ATV, and 5840 MHz is marginal. So 5665 is the general ATV preference

The FPV equipment receive and transmit frequencies are set using DIP switches, and most tune to 5665 MHz – but care needs to be taken when selecting equipment to make sure it does cover this frequency. Example channel tables are shown at the bottom of this page.

==Equipment==

The FPV units are widely advertised on eBay and other sites with titles similar to “Tarot 5.8G 600MW Telemetry TX/RX Combo for FPV Image Transmission TL300N” and are available at reasonable prices. The typical units are very small but have reasonable FM-TV performance with a quoted transmitter spec of 600mW output and receiver sensitivity of -80dBm. Amplifiers are available to raise the output power to 2 watts or more.

[[File:Tairot 1.jpg|400px]]

Be aware – we have found that on some receiver units, the video output is on the Red phono lead and not the expected Yellow lead!

Some other users' stations are described here [[5.6 GHz Equipment Examples]].

===Improvements to Commercial Units===

In CQ-TV 260, Achille I2GLI described improvements and additions to the Mateksys VTX-HV drone transmitter to make a high quality 18 watt output 5.6 GHz FM transmitter. One of the improvements was to replace the video and sound baseband circuitry. The published circuit diagram in online CQ-TV was a little unclear (although the printed version is good). The circuit diagram is reproduced below.
[[File:BandaBase.jpg|672px]]

===Mounting the equipment===
Due to the very high losses in co-ax cable at 5.6GHz it is recommended that you mount the units very close to the antennas and run long 12V dc, audio and video cables back down to the shack or operating position.

Be aware also, that whilst these units are very small they do run very hot in operation, and it is suggested that you provide a good heatsink for both Tx and Rx – mounting them in a diecast box on the back of their respective antennas is ideal.

[[File:GKQ 5.6v2.JPG|600px]]

Details of G8GKQ's transceiver setup is shown here (receiver unit on left & transmitter with fan on the right)

===Transmit amplifiers===

Whilst the basic units work very well and have been used to transmit over paths of 60km, power amplifiers to boost the 600mW transmitter signal to 2—4 Watts are available from several suppliers on eBay and other sites, and will significantly increase the path length that the units will work over. These amplifiers should be connected after the transmit unit, but before any antenna change over relay(s) – and remember that his will increase the volt drop on any long 12V cable feeding the transmitter at the masthead.

Be warned!! Several users have found these PAs to be "fragile", so you should always make sure that the antenna is connected – and all connectors done up tight – before applying dc or RF power. We are investigating whether they can be made more reliable by reducing the volts / input drive.

[[File:56PA.jpg|200px]]

==Antenna changeover relays==

The FPV equipment comes as separate Tx and Rx units. In order to operate on a single antenna, you will need an antenna changeover relay. Note, however, that the losses at 5.6GHz can be significant and care must be taken when wiring up the units to ensure RF cables are of good quality, and kept to a minimum length – semi-rigid cables fitted with SMA connectors are ideal.

PL259 and even BNC connectors are very lossy at 5.6GHz and should not be used, but the surplus SMA relays often available at rallys are ideal for 5.6 GHz.

See [[Antennae changeover relays|this wiki page]] for more details on suitable relays, 24 volt operation, and 4 port (or transfer) relays.

If no suitable relay is available, it may be cheaper to use separate antennas for receive and transmit as shown in the picture below – note the Tx and Rx units are mounted directly on the back of the flat panel antennas.

[[File:562.jpg|200px]]

===Reverse SMA===

Be aware that all the 5.6GHz FPV units use "reverse SMA" connectors (as used on WiFi equipment) and that all low-loss cables (unless bought specifically for the purpose) and surplus SMA relays will almost certainly have standard SMA connectors – which will not fit. Adapters from reverse to standard SMA are available on eBay or other suppliers – search for "RP-SMA to SMA adaptor" or similar wording.

==Antennas==

As 5.8GHz is used by broadband wireless networks, there is a wide choice of antennas available for use on 5.6GHz ATV. These can range from flat plates/panels to wire mesh (grid) dishes, as seen in the above pictures.

Horizontal polarisation has been chosen as the standard (waveguide feeds needs to have the long dimension of the aperture – and/or horn – vertically oriented when feeding dishes)

=== Satellite dishes ===

It is also possible to use a satellite mini dish with a suitable feed, such as a waveguide/horn to the design by G4NNS – see here for construction details: http://myweb.tiscali.co.uk/g4nns/FeedHorn.html

The picture shows a Sky mini dish fed with a WA5VJB log-periodic PCB feed http://www.wa5vjb.com/products1.html – these are available in the UK from G4DDK. http://www.g4ddk.com/Prices.html

Dishes of this size typically have a beam width of 4—8 degrees.

[[File:56 dish feed.JPG|400px]]

M1BKF found a very interesting 5.6GHz feed for standard f/d ratio satellite dishes; it contains what looks like a PCB yagi, and is available from:

<s>http://www.antennas-amplifiers.com/5.1-5.5-5.8GHz-WLAN-WiFi-Antenna/Feed-Illuminator-satellite-offset-dish-fd-0.5-0.8</s>

https://www.antennas-amplifiers.com/feed-Illuminator-satellite-offset-dish-fd-0.5-0.8

[[File:PCB dish feed.JPG|200px]] [[File:PCB dish feed2.JPG|300px]]

=== DIY BiQuad antennae ===

This web page http://buildyourownantenna.blogspot.co.uk/2014/07/double-biquad-sector-antenna-for-5-ghz-wifi.html has a well engineered double BiQuad antenna with a quoted 13dBi gain.

Note in the picture G8JAN has directly connected the Tx module to the antenna to avoid co-ax losses.

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

==Video equipment - Rx==
The receiver output will need to be directly connected to a monitor with a composite video input to view the received the signal – normally on a yellow phono or RCA connector.

===Video squelch defeat===

Beware of using modern flat-screen monitors which have a video squelch – these will not display noisy signals, and just give a blue screen until they get a strong video signal.

There are a number of circuits around to defeat the squelch and also improve the readability of the signal.

===Syncsmurf by PE1RQM=== – kits are available; details on the [https://translate.google.com/translate?hl=auto&sl=auto&tl=en-US&u=https%3A%2F%2Fwww.pe1rqm.nl%2Fsyncsmurf2%2F webpage here].

[[File:syncsmurf1.jpg|200px]]

Results are very impressive:

[[File:syncsmurf2.jpg|400px]]

===eachine FPV recorder===

Several people have reported that they are using these devices, available from various sites, and as well as defeating the monitor blue screen by inserting syncs on noise they have a single push button record facility. They record to an SD card which can be removed and the files viewed on a PC; users report that you need to use a good quality SD card, and that they have had problems with Kingston branded cards – Sandisk are preferred.

[[File:emachine dvr.JPG|300px]]

===Video sync processor===

[[File:cqtv 129.jpg|300px]]

Or any video sync processor may be usable such as the Advanced Converter Enhancer used by many stations on 23cms FM TV transmissions.

[[File:ACE.jpg|300px]]

==Video equipment - Tx==
An old camcorder with a yellow phono "video out" socket is an ideal video and audio source for the transmitter.

Don't forget that you will need to display your call sign to remain legal. This can be a video generator, a .jpg card reader with video out, or a piece of card with your call sign scribbled on it!

===Media card reader===

A simple way to generate test patterns is to use a media card reader loaded with .jpg files – these are available on several sites, just search for "SD card media AV player" – but make sure you get one which outputs PAL video.

[[File:av player.JPG|200px]]

===PicDream===
The PicDream project uses a single PIC chip and a 4MHz crystal to generate a black and white test pattern – simple but effective – the original project was described in CQ-TV 180 and re-printed in CQ-TV 247.

[[File:Picdream 247.JPG|400px]]

The PIC code is available for download here: batc.org.uk/cq-tv/software/picdream.zip

===PicDream II===
The PicDream II project uses a PIC chip and an AD724 PAL ecnoder chip to generate a colour test pattern with moving insets. The text and colours on the test pattern can be set through it's serial link.

Further information is at https://github.com/F1CJN/PICDREAM-II

===Raspberry Pi - PA3CHM image generator===

CQ-TV 247 published details of a simple RPi-based test card generator by Ernest PA3CHM.

[[File:PA3chm.JPG|400px]]

Full details are on his website: http://www.pa3hcm.nl/?p=248

===Raspberry Pi - Portsdown patterns===
The BATC Portsdown project can be configured to deliver composite video and audio out from the RPi multi-jack plug.

[[File:GKQ July 2017 (Small).JPG|400px]]

This can be test patterns, RPi desktop, or the Portsdown camera and microphone – [[Analog Video Output|see this wiki page for more details]] making the RPi the only piece of video/audio equipment you need to drive the 5.6GHz transmitter.

===Stand alone Raspberry Pi animated test card generator===
This is the stand alone version of the animated test card generator that is part of the Portsdown software
[[RPi Test Card| - see this wiki page for more details]]

==On the air==

Using dish aerials of 30—60cm, line of sight ranges of 80km can easily be achieved.

P5 (noise free) FM ATV pictures have been exchanged over a 138km path using the equipment described on this page – the picture below shows G4CPE/P on Dunstable Downs being received at the Ridgeway, near Didcot, over a slightly obstructed 66km path.

[[File:CPE 5.6GHz.JPG|400px]]

Dunkery Beacon near Minehead, to Cleeve Common near Cheltenham.
The picture shows G8GTZ/P received by G8GKQ/P over the 138km path.

[[File:snap5 small.jpg|400px]]

2018-04-21: The UK "record" for a contact using standard FPV units was increased to 153km between GW3NWR/P at Bylchau, North Wales to M0KPW/P and G0HIK/P at the Kirkstone Pass Inn, Cumbria.

This has since been surpassed.

==FM voice only==

Several stations in the Gloucester and Bolton area are using these units for wideband FM voice only. This is achieved by simply putting high level (1V peak-peak) audio on the yellow video TX phono input – this modulates the main high level carrier with audio rather than video (the two audio phono connectors – red and white – can be ignored). On RX, the yellow phono connector of the receiver is simply connected to a line level input of an audio amplifier.

It is done this way because the two audio subcarriers transmitted by the unit are at a level 20dB lower than that of the main (video)carrier. However, as it is using the same bandwidth Rx and Tx system, performance will be no better than FM video – ideally the 480MHz RX IF would be tapped off in to an SDR or narrow band receiver to give significantly enhanced (+20db?) narrow band performance.

==Activity hot spots==

There is a Google map showing approximate locations of stations thought to be active on 5.6GHz FM – if you are on 5.6GHz, you can add or edit your station: https://www.google.com/maps/d/u/0/edit?mid=1e4keFSFWy6wLUQNF3IT3n6h90eU&ll=52.39133141509076%2C-1.8917942000000494&z=7

Known users include:

*Southern England = G8GKQ, G8GTZ, G0UHY, G8XZD, G4UVZ, G3VPF
*Dunstable area = M0SKM, G4CPE, G0WFT
*North-East = GB3KM, G1LPS, M0DTS
*Cheltenham = G0LGS, M0RKX and G4NZV (using WB audio only)
*Bolton Wireless Club = G4JLG, G6GVI, G8PEF, M0UFC, MW1FGQ (PW “Siren” Article)
*Ludlow, Shropshire = G8XYJ
*Yorkshire = G8BYN
*Norfolk = G4NJJ, G8JAN, G4WVU and M1BKF
*Cumbria - Barrow-in-Furness Radio Club project
*Merseyside - G3NWR

[[File:cpe2.jpg|400px]]

==More information==

Dave G8GKQ did a presentation at the BATC annual convention CAT17 in September 2017 on getting started on 5.6GHz ATV.
*The presentation is available here https://wiki.batc.tv/images/4/42/CAT17_5.6_GHzv2.pdf
*The video of the session is available on the BATC YouTube channel here https://www.youtube.com/watch?v=XJzGNsGmE9Y

==On line support / social media==

There is a thread running on the BATC forum where the ATV community are exchanging ideas and also posting results of the latest on air tests. https://forum.batc.org.uk/viewtopic.php?f=2&t=5026

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.

==Technical information==

===SM201R===
The large RX chip in most units has had the part number removed, however it appears that a lot of receivers use the SM201R module. The spec and pinout are shown below but notice the frequency range of this particular unit does not seem to cover 5665MHz, so make sure the one you buy does!

[[File:sm201r 2.jpg|500px]] [[File:sm201r 3.JPG|200px]]

[[File:sm201r 1.JPG|500px]]

===S meter output===

Looking at the above table, it appears that the RSSI is available on pin 17 of the SM201R and could potentially be used for a signal strength meter to help align the antennas when setting up a QSO.

It also appears that the SM201R uses a 480MHz IF (same as the Comtech) and potentially could be modified with narrower filters to improve RF performance.

====Tx and Rx perfomance====

Initial measurements suggest the TX bandwidth is 25—30MHz.

[[File:5.6GHz spectrum.jpg|500px]]

This accounts for the quoted RX sensitivity at -80dBm which may be improved by an LNA but will ultimately be limited by the RX IF bandwidth.

===Channel Listings===

As mentioned above, the channel settings vary from manufacturer to manufacturer. This table is taken from the Tarot data sheet which uses the SM201R module but does include 5665MHz:

[[File:Tarot_Channels.jpg|603px]]

And this is the table for the Eachine TS835 transmitter:

[[File:Channels_2.jpg|619px]]

This table is from a "Fat Shark" transmitter that does not cover 5665 MHz:

[[File:Fat_Shark.PNG|300px]]

3.4 GHz DATV

2018-09-23T18:02:47Z

G6jyb: /* Transmitting 3.4GHz DATV */

In 2014/5 the UK 9cm amateur band was reduced to 3400-3410 MHz (from 3475 MHz), along with restrictions in 13cm. Consequently it only has the room to run DATV. However these spectrum changes have prompted development work and the band has proofed useful for UK repeater outputs.

Reports from the repeaters on 3.4 GHz suggests it is very low noise spectrum and actually performs as well if not better than 2.3 GHz.

There is (or was) a lot of surplus transmit (and receive) equipment on the surplus market, mainly from the failed Ionica broadband wireless system, and it is a very easy band to get on to, both for Tx and Rx.

===Receiving 3.4 GHz DATV===

It is very easy to receive 3.4 GHz DATV on using C band satellite LNBs feeding directly in to a free to air satellite receiver or [[MiniTioune|MiniTiouner]] - no big antennaes, pre-amps or filters needed.

[[File:9cms rx.JPG|600px|center]]

A lot of people use the [http://www.titaniumsatellite.com/c1pll Titanium PLL LNB] available from ebay.

[[File:titanium lnb.jpg|200px]]

You can either use the LNB on it's own, build a simple horn from a Marks and Spencer cardboard box covered in tinfoil, shown above, or mount it on a Sky mini dish, shown below, to give more gain.

[[File:G8GTZ antennaes.jpg|400px]]

===Transmitting 3.4 GHz DATV===

It is suggested that rather than try to generate DATV directly on 3.4 GHz, it is easier and probably more efficient to generate the DATV signal using the Portsdown at a lower frequency and then converting up using a Narrow Band transverter. This can either be a commercial unit or home built using modules described below.

A few years ago there was a lot of surplus 3.4 GHz wireless broadband equipment available - you don't see some much now, but if available it can be easily converted to DATV operation.

====Airspan AS4000====

[[File:g6gvi9cm.jpg|400px]]
Photo from G6GVI web page

The Airspan AS4000 is an outdoor consumer unit operating in duplex mode (Tx and Rx) on 3.4 GHz - it needs DC supply, transmit IF and reference oscillator up the co-ax and sends rx IF down.

The unit IF is at 820 MHz and G6GVI and M0DTS have both modified the local oscillator by changing the reference oscillator and reprogramming the PIC to provide an IF at 1296 - power output is 100 - 200 miliwatts with no modifications.

However, it is now possible to just use the ADF4351 controlled by [[ADF435x PIC|Ron G7DOE's simple controller]] to provide an LO of 2970, which provides an IF at 432 MHz for Narrow Band and DATV use. The only other mods are to apply the IF signal after the 800 MHz IF filter and key the transmitter as shown on M0DTS site.

[http://www.qsl.net/g6gvi/9cm.html Link to G6GVI page]

[http://www.m0dts.co.uk/?tag=3.4GHz&item=50 Link to M0DTS page]

==== Ionica PA ====

[[File:s-l300.jpg|400px]]

Surplus units which require absolutely no modification to produce 15 watts NB or 5 watts DATV when driven by the AS4000

[http://dc2light.co.uk/9cmpamods.htm Link to GM4ISM page show how to use the Ionica PA]

====Ionica Big boards====

[[File:bb1.jpg|400px]]
Photo from G4BAO web page

Whole chunks of working circuits can be retrieved from the Ionica main board to make a simple transverter as described on John G4BAO's site - don't forget, it is much easier now as we can use the ADF 4351 as the Local Oscillator on any frequency you desire.

[http://www.bravoao.co.uk/g4bao/page8.htm Link to G4BAO site]

3.4 GHz DATV

2018-09-23T18:01:56Z

G6jyb: Editorial tweaks to intro

In 2014/5 the UK 9cm amateur band was reduced to 3400-3410 MHz (from 3475 MHz), along with restrictions in 13cm. Consequently it only has the room to run DATV. However these spectrum changes have prompted development work and the band has proofed useful for UK repeater outputs.

Reports from the repeaters on 3.4 GHz suggests it is very low noise spectrum and actually performs as well if not better than 2.3 GHz.

There is (or was) a lot of surplus transmit (and receive) equipment on the surplus market, mainly from the failed Ionica broadband wireless system, and it is a very easy band to get on to, both for Tx and Rx.

===Receiving 3.4 GHz DATV===

It is very easy to receive 3.4 GHz DATV on using C band satellite LNBs feeding directly in to a free to air satellite receiver or [[MiniTioune|MiniTiouner]] - no big antennaes, pre-amps or filters needed.

[[File:9cms rx.JPG|600px|center]]

A lot of people use the [http://www.titaniumsatellite.com/c1pll Titanium PLL LNB] available from ebay.

[[File:titanium lnb.jpg|200px]]

You can either use the LNB on it's own, build a simple horn from a Marks and Spencer cardboard box covered in tinfoil, shown above, or mount it on a Sky mini dish, shown below, to give more gain.

[[File:G8GTZ antennaes.jpg|400px]]

===Transmitting 3.4GHz DATV===

It is suggested that rather than try to generate DATV directly on 3.4GHz, it is easier and probably more efficient to generate the DATV signal using the Portsdown at a lower frequency and then converting up using a Narrow Band transverter. This can either be a commercial unit or home built using modules described below.

A few years ago there was a lot of surplus 3.4GHz wireless broadband equipment available - you don't see some much now, but if available it can be easily converted to DATV operation.

====Airspan AS4000====

[[File:g6gvi9cm.jpg|400px]]
Photo from G6GVI web page

The Airspan AS4000 is an outdoor consumer unit operating in duplex mode (Tx and Rx) on 3.4 GHz - it needs DC supply, transmit IF and reference oscillator up the co-ax and sends rx IF down.

The unit IF is at 820 MHz and G6GVI and M0DTS have both modified the local oscillator by changing the reference oscillator and reprogramming the PIC to provide an IF at 1296 - power output is 100 - 200 miliwatts with no modifications.

However, it is now possible to just use the ADF4351 controlled by [[ADF435x PIC|Ron G7DOE's simple controller]] to provide an LO of 2970, which provides an IF at 432 MHz for Narrow Band and DATV use. The only other mods are to apply the IF signal after the 800 MHz IF filter and key the transmitter as shown on M0DTS site.

[http://www.qsl.net/g6gvi/9cm.html Link to G6GVI page]

[http://www.m0dts.co.uk/?tag=3.4GHz&item=50 Link to M0DTS page]

==== Ionica PA ====

[[File:s-l300.jpg|400px]]

Surplus units which require absolutely no modification to produce 15 watts NB or 5 watts DATV when driven by the AS4000

[http://dc2light.co.uk/9cmpamods.htm Link to GM4ISM page show how to use the Ionica PA]

====Ionica Big boards====

[[File:bb1.jpg|400px]]
Photo from G4BAO web page

Whole chunks of working circuits can be retrieved from the Ionica main board to make a simple transverter as described on John G4BAO's site - don't forget, it is much easier now as we can use the ADF 4351 as the Local Oscillator on any frequency you desire.

[http://www.bravoao.co.uk/g4bao/page8.htm Link to G4BAO site]

70cm DATV

2018-09-23T17:55:51Z

G6jyb: Initial 437 MHz text

23cms ATV

2018-09-23T17:50:14Z

G6jyb: /* Frequency allocations */ editorials and better links

The 23cms band is the most commonly used band for ATV.

==Frequency allocations==
The UK allocation is from 1240 MHz to 1325 MHz and common ATV usage is as follows:

*1248 - 1249 MHz = repeater inputs

*1255 MHz = simplex

*1275 MHz = simplex or alternative repeater input as determined by the CAA (primary user).

*1300 - 1325 MHz = repeater outputs

For details of current 23cms ATV repeaters see https://www.ukrepeater.net/tvr.htm?filter1=23cm

For 23cms UK bandplan see https://rsgb.org/main/operating/band-plans/

For other 23cms information see the [https://wiki.microwavers.org.uk/1.3_GHz UK Microwave Group wiki page].

==23cms equipment==

===23cms FM ATV equipment===

The most commonly used FM ATV was made by Comtech - see this page for more details: https://wiki.batc.org.uk/Comtech_module

During the 1980's, Wood & Douglas produced a range of 1.3GHz FM TV equipment that gave many amateurs their first taste of microwave ATV operation. See this page for more details: https://wiki.batc.org.uk/Wood_%26_Douglas_FM_TV_equipment

The Solent range of ATV equipment was sold by the Worthing repeater group in the 1990s. See https://wiki.batc.org.uk/Solent_ATV_units

===23cms DATV equipmemt===

The BATC Portsdown project covers 23cms - see https://wiki.batc.org.uk/Portsdown_Transmitter_User_guide

===23cms Power amplifiers===

For 23cms Power amplifier designs see https://wiki.batc.org.uk/23cms_amplifiers

===23cms Filter designs===

For details on filters for 23cms see https://wiki.batc.org.uk/23cms_filters

71 MHz

2018-09-23T17:46:36Z

G6jyb: Editorial tweaks to intro for 71 - similar to 146

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===

===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.

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]]

146 MHz RB-TV

2018-09-23T17:34:41Z

G6jyb: Editorial tweaks to intro

UK radio amateurs with Full licences have been given access to an extension of the 2m band between 146 and 147 MHz, but only for experimental modes. This is done on an annual temporary basis and you will need to do an on-line application for a NoV to your current license - see these links:

* NoV Application: http://rsgb.org/main/operating/licensing-novs-visitors/online-nov-application/146mhz-147mhz-nov/
* Additional RSGB guidance on 146 and 71 MHz at https://rsgb.org/main/operating/band-plans/vhf-uhf/vhf-spectrum-release/

The RSGB band plan now includes (and encourages) the use of Reduced Bandwidth Digital ATV (RB-TV) using 500 kHz centred on 146.5 MHz. For more info on Reduced Bandwidth Digital television (RBTV) take a look at this [[:media:cqtvrbtv.pdf|RB-TV special edition of CQ-TV]].

===RB-TV equipment for 146 MHz===

RB-TV on 146 MHz is not possible using "normal" DATV equipment and requires the use of equipment developed specially for the mode. For more technical details take a look at our getting started guide to RB-TV. [[Media:Getting Started with RB-TV.pdf|Getting Started with RB-TV]]

====Transmit Equipment====

*The BATC Portsdown is great project involving some simple construction to get on air on 146 MHz - [[The Portsdown Transmitter|see this introduction page.]]

* The DATVExpress project offers a versatile and flexible transmit system for 146 MHz.

====Receive equipment====

Due to the very low symbol rate, normal Set top boxes and satellite receivers will not receive RB-TV. The MiniTioune project was developed specifically to receive RB-TV - [[MiniTioune|more details can be found on this wiki page.]]

Unless you use the new [[Serit tuner|Serit tuner with your MiniTioune]], standard satellite tuners will not cover 146 MHz and you will need an upconverter from 146 MHz to L band - you can either home brew the upconverter or use one of the following:

* Roberto Zech Elektronik DG0VE, upconverter, power amplifier, mixer/oscillator module, LNA etc.
* '''Update''' Sadly Roberto became SK in 2018; no alternative upconverter suppliers known at present.

===146MHz pre-amps===

You will need a filtered pre-amp before any up converter or tuner.

* The DG8 144 - 147 MHz pre-amp with filtering has proven to work very well on 146 Mhz RB-TV: - http://www.ifwtech.co.uk/g3sek/vhfdx/dg8-preamp-v7.pdf . Note kits were available from G4HUP who suddenly became SK in Feb 2017. Short kits are currently available from SDR-Kits. https://www.sdr-kits.net/DG8-Pre-Amp-2M-Short-Kit

* Minikits in Australia do a pre-amplifier but it may need more filtering. http://www.minikits.com.au/electronic-kits/rf-amplifiers/rf-preamplifiers/2m-RX-Preamplifier

====Filters====
As the VHF spectrum is very crowded and we are operating close to the FM transmitter band and the 2mt amateur band, filters are essential on both transmit on recieve - not only to project other users against spurious from DATV transmissions but to avaoid blocking of the DATV reciever.

Details of suittable filters are listed [[146 MHz filters|on this wiki page.]]

====Power amplifiers====

See this [[Power amplifiers|wiki page]] listing considerations and designs for 146 MHz power amplifiers.