Listening to ASRTU-1 (AO-123) FM satellite Johnson Francis | June 9, 2025 | Amateur Radio (Ham Radio) | No Comments Last year I had posted about the launch of ASRTU-1 FM satellite. Subsequently it has been assigned the name AO-123 by AMSAT. Uplink frequency is 145.850 MHz, with a CTCSS tone of 67 Hz, the same as that of SO-50. Downlink is on 435.400 MHz.