Satgen103 The HF Supersats by GM4IHJ 18 March 91 RS10 RS11 RS12 RS13 Uplink 145.86 to 145.9 145.91 to 145.95 145.91 to 145.95 145.96 to 146 Downlink 29.36 to 29.4 29.41 to 20.45 29.41 to 29.45 29.46 to 29.5 Robot up 145.82 145.83 145.831 145.841 Robot down 29.403 29.407 29.454 29.503 Beacon 29.357 29.407 29.408 29.458 Only one of the above set is on at any one time. RS12 is likely to replace RS10 soon as the active unit. RS makes 13 orbits per day , of which 9 consecutive orbits are in range of UK . Downlink telemetry on the lower band edge beacon is CW . Excellent 2 way CW and USB communications available to USA, Asia , and Africa. At present March 91 the 9 orbits in range occupy a window commencing at about 1900ut going through midnight to 1100 ut the next day. Ionospheric Experiments. For the Short Wave Experimenter the RS beacon is regularly heard around the world by way of ionospheric propagation . RS is often picked up over Canada as it comes towards UK some 16 minutes or so before it reaches AOS ( Acquisition of satellite at UK horizon ). It is then usually lost just before AOS time then picked up again almost immediately at AOS . It then remains audible until it goes below the UK horizon at LOS ( Loss of Satellite at Horizon), and on some rarer occasions it continues to remain audible after LOS for perhaps 16 to 20 minutes more. Sometimes going missing for 3 minutes during this after LOS sub horizon passage, sometimes steadily audible throughout. Very often these anomalously propagated signals have a very rough note. Sometimes RS is heard clearly with a second rougher note 200 or 300 Hz different in frequency alongside the clear note. Equally interesting the Doppler shift of the RS signal is often not correct for a direct great circle path from the satellite to UK. In fact RS can often be heard on orbits which come nowhere near UK .Prime time for these long range anomalously propagated signals is when RS is overhead its local sunset sunrise grey line in the ionosphere. Eg when south eastern Australia has just had sunset, RS flying south of Australia can sometimes be heard all the way back westward to UK by a sunlit propagation route provided that the ionosphere under the satellite is thin ( ie after sunset ) with low MUF so that the signal gets down through to chordal hop to the ionospher underside over sunlit Java where it gets its first propagation refraction towards UK , at around 1100 ut . All in all RS provides a feast of simple satellite communications and superb ionospheric propagation experiments. 73 de John GM4IHJ @ GB7SAN