ARRL

ARRL Satellite Bulletin ARLS006 (2002)

SB SPACE @ ARL $ARLS006
ARLS006 AMSAT-OSCAR 7 returns to life

ZCZC AS06  
QST de W1AW  
Space Bulletin 006  ARLS006
From ARRL Headquarters  
Newington, CT  June 25, 2002
To all radio amateurs

SB SPACE ARL ARLS006
ARLS006 AMSAT-OSCAR 7 returns to life

The AMSAT-OSCAR 7 satellite suddenly has come back to life after
being dormant for more than 20 years. First heard June 21 by Pat
Gowan, G3IOR, AO-7 subsequently has been monitored and used by
several other amateurs. AO-7 was launched November 15, 1974. It
remained operational for more than six years before succumbing to
battery failure in 1981.

''I'm blown away,'' was the reaction of AO-7 Project Manager Jan King,
W3GEY. ''So, this old war horse of a spacecraft seems to have come
back from the dead if only for a few moments.''

Exclaimed satellite enthusiast and AMSAT Vice President for User
Services Bruce Paige, KK5DO, ''This is really awesome.'' Paige said
the latest turn of events makes AO-7 is the oldest amateur satellite
that's still working. AMSAT-NA has now listed AO-7 as
''semi-operational.''

AMSAT says it seems certain the satellite is running only off its
solar panels, not from the onboard batteries, so it will be
operational only while it's in sunlight. King speculates that the
batteries, which shorted as they failed two decades ago, now are
''un-shorting'' and causing the satellite to come back to life.

For those attempting to use AO-7, Mode A (2 meters up/10 meters
down) is not a problem, but Mode B (70 cm up/2 meters down) is.
Because of changes in the international Radio Regulations that went
into effect in the 1970s as AO-7 was under construction, the 432.1
MHz uplink frequency is no longer authorized for space
communications.

AMSAT advises potential users that when uplinking to a satellite,
they are operating in the Amateur-Satellite Service. AMSAT says
uplinking to AO-7 ''is possibly illegal since the Amateur Satellite
Service is not permitted at 432.1 MHz.'' The current band plan
earmarks the 432.1 MHz range for weak signal work. Section 97.207(c)
of the FCC's rules authorizes space station operation only in the
435-438 MHz segment.

Built by a multinational team under the direction of AMSAT-NA, AO-7
carries Mode A (145.850-950 MHz uplink; 29.400-500 MHz downlink) and
Mode B (432.180-120 MHz uplink; 145.920-980 MHz downlink) linear
transponders plus beacons on 29.500 and 145.700 MHz. A 2304.1 MHz
beacon was never turned on because of international treaty
constraints.

AMSAT has additional information on AO-7 on its Web site,
http://www.amsat.org.
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