Saudi-Sat SO-50

SO-50 hosts various experiments, including a mode J FM amateur repeater operating at 145.850 MHz uplink and 436.795 MHz downlink. This repeater is available to amateur radio operators worldwide as long as power allows. To activate it on demand, you need a 67.0 Hz PL tone on the uplink. There’s also a 10-minute timer that must be armed by transmitting a 2-second carrier with a 74.4 Hz PL tone.

The repeater features a compact VHF receiver with a sensitivity of -124 dBm and a 15 kHz IF bandwidth. Its receive antenna is a 1/4 wave vertical located at the top corner of the spacecraft. The received audio is filtered, conditioned, and gated in the control electronics before being sent to the 250 mW UHF transmitter. The downlink antenna, a 1/4 wave mounted at the bottom corner, is tilted inward at a 45-degree angle.

Memory Name	Transmit	Receive	CTCSS Tone
SO-50 ON	145.850 MHz	N/A – Timer Activation	74.4 Hz
SO-50 1	145.850 MHz	436.805 MHz	67 Hz
SO-50 2	145.850 MHz	436.800 MHz	67 Hz
SO-50 3	145.850 MHz	436.795 MHz	67 Hz
SO-50 4	145.850 MHz	436.790 MHz	67 Hz
SO-50 5	145.850 MHz	436.785 MHz	67 Hz