LO filters - Revision history

G8GTZ: /* Parts List */

2017-11-14T12:00:10Z

Parts List

2017-11-14T11:59:43Z

Parts list and schematic

2017-11-10T19:30:12Z

Parts list and schematic

2017-11-10T19:29:58Z

Switched multi-band filter design

2017-11-10T19:29:03Z

Parts list and schematic

2017-11-10T19:28:06Z

Switched multi-band filter design

2017-10-26T17:41:50Z

2017-05-30T21:40:12Z

2017-04-03T13:59:06Z

2017-03-07T09:02:51Z

Switched multi-band filter design

← Older revision		Revision as of 12:00, 14 November 2017
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	Parts list is available as bare bones parts list, or Bill of Materials, in an .xls file which you can upload to [http://www.digikey.co.uk Digikey].		Parts list is available as bare bones parts list, or Bill of Materials, in an .xls file which you can upload to [http://www.digikey.co.uk Digikey].
−
−	If you wish to make any changes such as select the larger heatsink option, use an external regulator, a different heatsink or delete components you already have, simply amend the item in the "Quantity" column before uploading to Digikey.

	To use the facility, sign in to digikey (you will need to register first) and go to my basket and [http://www.digikey.com/en/help/features-updates/upload-to-cart follow these instructions]. You then need to make the following changes:		To use the facility, sign in to digikey (you will need to register first) and go to my basket and [http://www.digikey.com/en/help/features-updates/upload-to-cart follow these instructions]. You then need to make the following changes:

@@ Line 17: / Line 17: @@
 The filter makes a significant difference to the transmitter performance and we recommend everyone should include one in the system.   Spectrum plots of the filters and tables showing the detailed performance and output power of the Portsdown modulator board with and without filtering on the LO input [[LO Filter Performance|are available here]].
-====Parts list and schematic====
+====Schematic====
 The circuit diagram is here:
@@ Line 33: / Line 29: @@
   We do realise that the PCB contains some small surface mount parts but take a look at [https://www.youtube.com/watch?v=LSy3r85QB4E Colin's excellent video] and give it a go or build one of the simple single band filters detailed below.
 ===Single-band Filters===

@@ Line 30: / Line 30: @@
 [[:File:Portsdown LO Filter SS.pdf]]
 Blank PCBs are available in the [https://batc.org.uk/shop/portsdowntc BATC shop]
   We do realise that the PCB contains some small surface mount parts but take a look at [https://www.youtube.com/watch?v=LSy3r85QB4E Colin's excellent video] and give it a go or build one of the simple single band filters detailed below.

@@ Line 15: / Line 15: @@
 Note that R05 and R06 were not fitted before this photo was taken,  They are both required to be fitted for optimum performance.
- Blank PCBs are available in the [https://batc.org.uk/shop/portsdowntc BATC shop]
+The filter makes a significant difference to the transmitter performance and we recommend everyone should include one in the system.   Spectrum plots of the filters and tables showing the detailed performance and output power of the Portsdown modulator board with and without filtering on the LO input [[LO Filter Performance|are available here]].
 ====Parts list and schematic====
@@ Line 29: / Line 29: @@
 And the silk screen showing component placement is here:
 [[:File:Portsdown LO Filter SS.pdf]]
   We do realise that the PCB contains some small surface mount parts but take a look at [https://www.youtube.com/watch?v=LSy3r85QB4E Colin's excellent video] and give it a go or build one of the simple single band filters detailed below.

@@ Line 30: / Line 30: @@
 [[:File:Portsdown LO Filter SS.pdf]]
- The filter makes a significant difference to the transmitter performance and we recommend everyone should include one in the system.  We do realise that the PCB contains some small surface mount parts but take a look at [https://www.youtube.com/watch?v=LSy3r85QB4E Colin's excellent video] and give it a go or build one of the simple single band filters detailed below.
+  We do realise that the PCB contains some small surface mount parts but take a look at [https://www.youtube.com/watch?v=LSy3r85QB4E Colin's excellent video] and give it a go or build one of the simple single band filters detailed below.
 ===Single-band Filters===

@@ Line 13: / Line 13: @@
 [[File:PD LO filter.JPG|300px]]
-Note that R05 and R06 were not fitted before this photo was taken,  They are both required to be fitted for optimum performance.  Blank PCBs are available in the [https://batc.org.uk/shop/portsdowntc BATC shop]
+Note that R05 and R06 were not fitted before this photo was taken,  They are both required to be fitted for optimum performance.
 The revised parts list is available here - minor errors corrected on 7th March and 3 April 2017.  Note that R08 is not used.

← Older revision		Revision as of 17:41, 26 October 2017
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−	~~Testing on the 3 prototype boards has shown that, due~~ to the square wave output of the ADF4351, ~~it will need~~ filtering between the output of the ADF4351 module and the modulator board LO input when used on 146 and 437 MHz. This filter only needs to be a simple low pass filter to remove the third harmonic and no filtering is required on 23cms.	+	Due to the square wave output of the Portsdown ADF4351 Local Oscillator module, filtering is required between the output of the ADF4351 module and the modulator board LO input when used on 146 and 437 MHz. This filter only needs to be a simple low pass filter to remove the third harmonic and no filtering is required on 23cms.

	The effect of running without a high pass filter on 146 and 437 is an imbalance in the modulator resulting in reduced MER and RF performance as seen on the screen shots below - it does not affect the transmitted spectrum and is OK to put on air.		The effect of running without a high pass filter on 146 and 437 is an imbalance in the modulator resulting in reduced MER and RF performance as seen on the screen shots below - it does not affect the transmitted spectrum and is OK to put on air.

@@ Line 15: / Line 15: @@
 Blank PCBs are available in the [https://batc.org.uk/shop/portsdowntc BATC shop]
-The parts list is available here.
+The revised parts list is available here - minor error corrected on 7th March.
-[[:File:LO Filter Parts.xls]]
+[[:File:LO Filter Partsv2.xls]]
 The circuit diagram is here: