The repeater is operational from when the satellite's footprint hits 38 degrees North lattitude until it leaves about 37 degrees North lattitude during the daylight only. The repeater may be activated on an ad-hoc basis during evening passes on weekends and weekdays.
Users are reminded that as an FM-mode repeater, AO-27 is subject to FM "capture effect" and can only transmit one signal at a time. Users are asked to cooperate, keep calls short, give breaks so as many stations as possible can work a pass, and above all, listen before and while transmitting. The satellite has a very sensitive receiver, and stations running approximately 25 watts power to moderate-gain omnidirectional antenna can get a good uplink signal into the satellite. A sensitive UHF FM receiver with a preamplifier and an omnidirectional antenna can receive AO-27's downlink with some fading; moderate-gain directional arrays should provide a solid receive signal. Remember to correct for the +/- 9 kHz of Doppler shift on the 436.797 MHz downlink signal during a pass. No Doppler correction is needed for the 145.850 MHz uplink signal.
Users are asked not to transmit on 145.85 MHz if they do not hear the satellite's downlink so as to avoid possible interference to other satellite uplinks and downlinks on adjacent frequencies.
We will attempt to provide regular bulletins to keep the satellite user community informed of AO-27's status and availability. For now, questions regarding AO-27 may be forwarded to ka1lm@amsat.org.
Michael Wyrick, N4USI
wyrick@interf.com
Control Operator, AO-27
Systems Engineer, Interferometrics
Steve Greene, KA1LM
ka1lm@amsat.org
Return to AO-27
Last update February 12, 1995 - N7HPR