Satellite Setup

In one of my earlier posts I mentioned I had started looking at getting setup for operating on satellites. Well I have finally managed to get this working.

The setup consists of the following:

2m Wimo X-quad beam with phasing harness to make it RHC Polarised

70cm Wimo X-quad beam with phasing harness to make it RHC Polarised

SDR Play SDR receiver

IC7100 Transceiver for the uplink

Comet MX-72N duplexer.

SDR Console Software for tracking and Doppler control

It has taken me a number of weeks to get this all working. I’m not using an elevation rotator as these antennas are fixed at approx 30 deg elevation on top of my UB20-Mx beam. Getting the Tx and RX and the rotator to track was the easy part, thanks to SDR Console being able to control the Doppler on the SDRPlay and also the IC7100 at the same time is great. What I could not figure out was by I could not hear myself back. On one of the passes on an FM only satellite I heard 2M0SQL, Peter, who I have worked before using my handheld setup. I looked him on on QRZ and saw that he has the same antennas as I do, so I sent him an email message describing my issue. He was very kind in replying and giving me a pointer to an Amsat webpage describing receive desense and how to remedy it.

The solution was to insert a duplexer on the 70cm side to provide receiver isolation with approx 60dB. This was almostlike turning the lights on, suddenly I could hear myself back!

So since then I have been able to make a number of QSOs on a number of the Linear satellite and a couple of the FM satellites.

Thanks Peter for your help!

Until the next time

73 Rob

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