Using WebSDRs Worldwide for the ISS

ISS SSTV and Packet Radio signals on the SUWS WebSDR

ISS SSTV and Packet Radio signals on the SUWS WebSDR

Martin Ehrenfried G8JNJ describes how he uses WebSDR’s to listen to ISS transmissions on 145.800 and 145.825 MHz. The SUWS SDR at Farnham can even receive the 143.625 MHz ISS comms channel.

We were treated to more Slow Scan Television (SSTV) pictures from the International Space Station (ISS) on the weekend of April 11/12.

During the Sunday evening passes a Cosmonaut suddenly decided to try some ad-hoc voice contacts between SSTV transmissions. Quite a few other stations were calling RS0ISS, but I didn’t hear any actual two-way exchanges. I made a very late, hurried and half-hearted attempt to call near the end of the pass, when my collinear antenna was most likely to be effective, but the ISS was very quickly out of range.

144 MHz G8JNJ prototype helix antenna used at SUWS WebSDR

144 MHz G8JNJ prototype helix antenna used at SUWS WebSDR

I was also monitoring the Russian VHF-2 comms frequency 143.625 MHz FM on the new extended 143 MHz band on the SUWS WebSDR in a second browser window, and heard a very short transmission from a Cosmonaut near the end of the UK pass. I suspect they were attempting to call Moscow as they started to come into range.

When the ISS dropped out on the SUWS WebSDR, I swapped over to the Russian WebSDR and heard some full contacts during a long pass over the Russian mainland.

With the exception of Asia (Bangkok SDR seems to be very deaf) it’s now possible to switch between WebSDR’s at different locations and catch just about all Amateur transmissions from the ISS. In fact it’s possible to set-up multiple browser tabs, one for each WebSDR and just leave them set on 145.800 MHz FM with squelch enabled, so that voice or SSTV traffic can be heard on each SDR in turn when the ISS passes into range.

These are two sound files captured on the WebSDR’s record function

SDR 22 DX recording

SUWS recording

Martin – G8JNJ

WebSDRs which may be used to receive the ISS and some amateur satellites are:
United Kingdom Farnham IO91OF
Russia Ruzaevka LO24LA
Russia Belgorod
Eastern Russia Barnaul NO13TH
Canada East coast
USA West Coast
South Africa
Thailand Bangkok