China's CAMSAT has announced that two Amateur Radio payloads piggybacked on the optical remote-sensing microsatellites OVS-1A and OVS-1B were launched on June 15 from the Jiuquan Satellite Launch Center. The primary launch mission is a hard X-ray modulation telescope satellite (HXMT). The Amateur Radio payloads are designated CAS-4A and CAS-4B.

CAS-4A (call sign BJ1SK) carries an inverting U/V inverting transponder, with a CW telemetry beacon at 145.888 MHz and 4.8 kb GMSK telemetry at 145.835 MHz. The transponder uplink is 435.220 MHz; the downlink is 145.870 MHz.

CAS-4B (call sign: BJ1SL) carries an essentially identical inverting U/V linear transponder, with a CW telemetry beacon at 145.910 MHz and GMSK telemetry at 145.890 MHz. The transponder uplink is 435.280 MHz; the downlink is 145.925 MHz MHz.

“The frequencies of transponders are center frequencies, and uplinks/downlinks are both 20 kHz wide,” CAMSAT’s Alan Kung, BA1DU, explained. “The transponders are linear and good for SSB/CW operation.”

Both CAS-4A and CAS-4B are equipped with quarter-wave monopole antennas for VHF and UHF. — Thanks to Alan Kung, BA1DU/CAMSAT