It sounds unbelievable in times when we count the lifespan of electronics in months, but the AO-27 satellite celebrated its 27th birthday. It was launched on September 26, 1993 by the Ariane-4 carrier. The AO-27 was the first truly usable FM satellite that allowed amateur radio communication with simple equipment. It was also the first satellite through which a connection was made D-Star fashion. The orbit at an altitude of 800 km enables a solid coverage of the earth's surface. For the latest information on the AO-27, visit https://www.ao27.net/
Operation is carried out on downlink 436.795 MHz with uplink 145.850 MHz in FM mode. Of course, it is necessary to take into account Doppler effect frequency shift - mainly in the 70 cm band. Both AO-27 antennas have linear polarization.