Difference between revisions of "146 MHz filters"

Revision as of 10:27, 21 September 2017

170MHz Low pass transmit Filter

Minikits in Australia make a really good low pass filter which is ideal for use with the Portsdown or other 146 Mhz DATV transmitters.

Low pass 7 pole 144 MHz filter

A simple DIY filter was originally published in the RSGB VHF manual and described in CQ-TV 250

The coils are wound on a 3/8" or 9.5mm drill.

Example of the design built by M0YDH with help from G8GTZ who formed the coupling capacitor between sections from the loop of red wire and the test results from workshop at CAT17

144 MHz band pass filter by YU1LM

This is a nice easy filter to build and can be used on the output of the Portsdown transmitter before any power amplifier stages.

File:2m BP FILTER-YU1LM.pdf

There is also some discussion on the Funcube dongle website of the YU1LM filter http://www.funcubedongle.com/?p=456

Manufacturers of 144 - 148 MHz filters

Anntenae-amplifiers in Serbia do some very nice filter for all bands at reasonable cost - the 144MHz unit is very impressive: http://www.antennas-amplifiers.com/144MHz-Bandpass-Filter-BPF

OCI is a Canadian manufacturer [1]

QRP-Labs sell a 144MHz low pass filter kit for <10W duty at $4.65 [2]

@@ Line 1: / Line 1: @@
-===170MHz Low pass transmit Filter===
+==170MHz Low pass transmit Filter==
 [http://www.minikits.com.au/electronic-kits/filter-kits/vhf-lowpass-filters/LPF7-170M Minikits in Australia] make a really good low pass filter which is ideal for use with the Portsdown or other 146 Mhz DATV transmitters.
@@ Line 6: / Line 6: @@
 [[File:lpf7-170m-a-225x225.jpg|200px]]
+== Low pass 7 pole 144 MHz filter ==
-  Or there are a number of published designs which are easy to build using a minimum of tools:
+[[File:YU7EF2m LPF_7 pole .jpg|300px]]  [[File:JTT filter.jpg|300px| Response of YU7EF filter built by G7JTT]]
-=== Low pass 7 pole 144 MHz filter ===
-[[File:YU7EF2m LPF_7 pole .jpg|300px]]  [[File:JTT filter.jpg|300px| Response of YU7EF filter built by G7JTT]]
+== A simple DIY filter was originally published in the RSGB VHF manual and described in CQ-TV 250==
+The coils are wound on a 3/8" or 9.5mm drill.
-=== A simple DIY filter was originally published in the RSGB VHF manual and described in CQ-TV 250===
-The coils are wound on a 3/8" or 9.5mm drill.
 [[File:146 filter.JPG|300px]]
-===144 MHz band pass filter by YU1LM===
+Example of the design built by M0YDH with help from G8GTZ who formed the coupling capacitor between sections from the loop of red wire and the test results from workshop at CAT17
+[[File:20170914 CQTV250 2m BPF M0YDH.jpg|400px| ]]         [[File:t.jpg|500px]]
+==144 MHz band pass filter by YU1LM==
 This is a nice easy filter to build and can be used on the output of the '''Portsdown''' transmitter before any power amplifier stages.
 [[File:yuilm.jpg|200px]]
@@ Line 30: / Line 36: @@
 There is also some discussion on the Funcube dongle website of the YU1LM filter http://www.funcubedongle.com/?p=456
-=== Manufacturers of 144 - 148 MHz filters===
+== Manufacturers of 144 - 148 MHz filters==
+* Anntenae-amplifiers in Serbia do some very nice filter for all bands at reasonable cost - the 144MHz unit is very impressive: http://www.antennas-amplifiers.com/144MHz-Bandpass-Filter-BPF
 *OCI is a Canadian manufacturer [http://www.ocicom.com/index.php/amateur-radio/products/2-meter-bandpass-filter]
 * QRP-Labs sell a 144MHz low pass filter kit for <10W duty at $4.65 [https://www.qrp-labs.com/lpfkit.html]
+[[File:20170914 QRP Labs 4m and 2m LPF.jpg|200px|Low pass filter kits from QRP-Labs built by M0YDH for Portsdown TX use. 4m on left and 2m on right.]]