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AMSAT Celebrates 40 Years in Space for AO-7


Saturday, November 15, will mark 40 years since the AMSAT-OSCAR 7 (AO-7) ham radio satellite went into space from Vandenberg Air Force Base in California. Special Event W7O will be on the air November 15-24 to commemorate the launch of AO-7, the oldest working Amateur Radio satellite. Satellite aficionado Patrick Stoddard, WD9EWK/VA7EWK, who secured W7O for the occasion, plans to work satellite passes during the special event from Arizona, including AO-7 passes. He also hopes to recruit other operators to participate in the celebration from other locations and on other bands, including HF.

“I am thinking of incorporating the original QSL card design AMSAT used to confirm AO-7 reception reports from the 1970s in the W7O card,” Stoddard said. He’s still seeking a good scan of both sides of the 1970s card. “The QSL cards will be printed after the W7O activity wraps up,” he added, noting that he plans to upload W7O contacts to ARRL’s Logbook of The World (LoTW).

AO-7 was the second so-called “Phase 2” Amateur Radio satellite that AMSAT-NA constructed and launched into low-Earth orbit. It remained in operation until a short circuit occurred in a battery in 1981. More than 20 years later, however, AO-7 unexpectedly returned to life, its 2 meter beacon showing up on 145.9775 MHz. AMSAT describes the Mode A/B bird as “semi-operational” and dependent upon its solar panels for a reliable power source; AO-7 works only as long as its solar panels are illuminated by sunlight. Satellite experts speculate that AO-7’s resurrection occurred when the short circuit in the battery opened up for some reason, allowing the solar cells to power the spacecraft. When the satellite goes into eclipse, it powers down. Since the satellite became undead, terrestrial users have enjoyed numerous contacts via AO-7.

The eclipse period, during which AO-7 falls silent, lasts from mid-spring to mid-summer. According to its operating plan, AO-7 switches to Mode B (70 centimeters up/2 meters down) at 0000 UTC. AO-7 has beacons on 29.502 MHz (used in conjunction with Mode A) and, nominally, on 145.972 MHz (used in conjunction with Mode B and Mode C — low power Mode B). The 435.100 MHz beacon has an intermittent problem, switching between 400 mW and 10 mW

Stoddard said he has had heard from a lot of hams interested in taking part in the W7O operation, but he pointed out that W7O can only be used in areas where Amateur Radio is regulated by the FCC. He said that he’s seeking satellite operators in different parts of the US, especially in the Eastern US capable of working Europe, North Africa, and South America, as well as other North American station.

In addition to satellite bands, Stoddard said, he’ll take signups for 1-hour increments on HF (excluding 60 meters) plus 6 meters, for CW, SSB, and digital modes, but he’d like to avoid having two stations operating at W7O on the same band/mode combination at the same time. Contact Stoddard for more information.

"Once I get some operating commitments from operators, I will publish the schedule through a link on my WD9EWK entry and my web page,” Stoddard said. “This way, others will know where and when to look for W7O during this 10-day period.”

AMSAT has posted a series of photos documenting the early OSCAR years, including AO-7. — Thanks to AMSAT-NA, AMSAT News Service




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