FM Interference to Linear Transponder Satellites

Alexandru Csete OZ9AEC has previously written about interference from FM stations on the HO-68 linear transponder. He now reports that other satellites with linear transponders (designed for SSB/CW use only) also suffer from local FM traffic by people who haven’t got a clue that they are transmitting in the satellite uplink segment of the 2 meter band (145.8-146.0 MHz).

This recording was made on Saturday, May 5, 2012 using the AMSAT-UK FUNcube Dongle and Gqrx SDR. It shows very strong FM transmissions on the FO-29 linear transponder which could be from Spain or Portugal. The topic appears to be chocolate. Alexandru says – If you know who these people are, be sure to send them a QSL card!

The use of FM on a linear transponder satellite reduces the lifetime of both the batteries and the transponder itself.

Watch FM on FO-29 amateur radio satellite

How to work the SSB amateur radio satellites

AMSAT-UK FUNcube Yahoo Group