Oscar 7 and 73 – The old and the new

SUWS WebSDR showing AO7 and 73 on April 3, 2014 at 1040 GMT

SUWS WebSDR showing AO7 and 73 on April 3, 2014 at 1040 GMT

A very good set of co-incident passes of both the AO-7 and FUNcube-1 AO-73 amateur radio satellites occurred over the UK on the morning of Thursday, April 3. The two satellites were launched 39 years apart, AO-7 on November 15, 1974 and FUNcube-1 AO-73 on November 21, 2013.

Simultaneous downlinks from both satellites could be clearly seen and heard on 2m, via the Southampton University Wireless Society (SUWS) online WebSDR at http://websdr.suws.org.uk/ which is available for use world-wide.

23cm_WebSDR_Antenna_up_mastNew Helical antennas designed by Martin Ehrenfried, G8JNJ, the installation of pre-amplifiers by Noel Matthews, G8GTZ, and a new PC build by Phil Crump, M0DNY have helped to dramatically improve the overall performance, especially on the 2m and 70cm Amateur bands.

The FUNcube-1 AO-73 BPSK telemetry beacon on 145.935 MHz is now up to 20dB above the receiver noise floor, and several stations using SSB, including Martin, G8JNJ, could be clearly heard on the 2m downlink via the SDR during last weekends transponder tests.

More improvements are in the pipeline, which we hope will help to further improve the receive sensitivity and reduce the level of interfering signals that can be observed on 2m.

Anybody can operate the SUWS WebSDR to receive signals from Satellites, and we really appreciate users leaving a message in the chatbox to let us know what they have heard.

Martin – G8JNJ

SUWS WebSDR http://websdr.suws.org.uk/