karn (09/21/82)
I just received a phone call from Vern Riportella, WA2LQQ, AMSAT Executive VP. Rip informs me that last night, the SRI team using the 150 foot antenna has successfully commanded Uosat-Oscar-9, turning off the beacons which have jammed the command receivers for quite a few months now. The problem was that no interlock circuit had been provided in the spacecraft to prevent the inadvertent turning on of both the 2 meter and the 70 cm beacons, which desensitized the command receivers also on 2 and 70 cm. Naturally, a mistake was made, and somehow both beacons had been commanded on. The SRI dish, plus a kilowatt of transmitter power, was finally able to override the strong local signal in the command receiver (probably on 2 meters, but that hasn't been confirmed) and turn off a beacon to allow commanding on that band. Initial telemetry reports after the two-meter beacon was turned back on and telemetry encoding enabled indicate that the spacecraft is still in excellent health. Uosat-Oscar-9 may be received with a conventional amateur 2-meter receiver on 145.825 mhz FM. If you have a Bell 202 (NOT 212) modem and a conventional terminal, you can decode its telemetry. Just connect the terminal to the modem and set the terminal to 1200 or 300 baud, depending on the current telemetry speed. Phil Karn, KA9Q/2