Satgen273  Satellite Profile No2  Radiosport 10  by GM4IHJ      18 June 94
BID of this msg is SGEN273  Please use this BID if you retransmit this msg

RadioSport 10 is a typical member of the family of Mode A satellites which
accept a CW or USB uplink near 145.88 Mhz and send you a downlink near
29.38 MHz. Its orbit pattern is very similar to that of RS12, reported in
Profile No1, with a height of around 1000 kms, and an orbit period of
about 105 minutes and a near polar orbit of 82 degrees inclination, which
allows it to see the whole world twice a day. On any one day RS10
completes a little over thirteen and a half orbits of the earth, and of
these orbits a succession of 9 or 10 roughly 100 mins apart can be heard
by stations located above latitude 52 degrees. Stations nearer the equator
see two blocks each of 3 or 4 orbits, with a gap of  4 to 5 hours between
the two orbit blocks. When RS10 is west of UK it can be used for
communication with stations in eastern USA. When it is east of UK it
provides communications link facilities to station in western Asia.
RS10 is a strictly " no frills" satellite Easy to use by beginners, and
yet, very useful indeed for specialist long range DX communicators and
propagation experimenters.
To access RS10 transponder , listen for the beacon on 29.358 MHz CW and
check that you can track it easily. Then tune your transmitter to 145.88
MHz and listen around 29.38 MHz. You should hear your own signal being
transponded back to you 116.5 MHz plus or minus 2 or 3 kHz of doppler
shift below your transmitted frequency. Remember doppler is highest when
you first acquire the satellite, dropping to lowest as the satellite
descends to your far horizon.
Because of its simple equipment requirements of a 2m CW/USB transmitter
and an ordinary HF 10m receiver, it is possible to use this near earth LEO
satellite from a station equiped with minimal fuss dipole or wire
antennas. RS10 always has plenty of users , so finding someone to talk to
is no problem, but if you want to sample communications to stations at
extreme range in other continents you can improve your station by fitting
directional antennas. Please note that these need very little training
motion because best long distance traffic occurs when the satellite is
near your horizon and changing its bearing very slowly. RS10 type sats
have been around for 22 years. So many operators have lots of experience.
Do not be put off by this , they are always pleased to hear new stations. 
There is a lot of interest even now in RS10s predecessors ( Oscar 6, Oscar
7A, Oscar 8A, Radiosports 1 and 2, and 5 to 8 ). All of them are still in
orbit but most of them are now dead, though several far exceeded the life
expectancy we get from most commercial sats. RS1 in particular suffered a
power supply battery failure which ended normal operation . But because
the failure "open circuited the battery " breaking its connection to the
power bus, the solar cells also on the power bus continued to power it up
when ever the sats solar cells were seeing sunlight. Result was RS1 went
on long after its designed life, gradually getting weaker as hard
radiation damaged its solar cells. So that eventual it did not have enough
volts to be "sane", although it continued at irregular intervals to send
meaningless morse code mumblings on it telemetry beacon (29.401 MHz).
Perhaps a special satgen is due one day to discuss these satellites that
refuse to die. Unfortunately I know of no authenticated reports of RS1 or
any other of these old Mode A birds, being heard in the 1990s. Please note
if you do hear them they were much higher than RS10 and therefore had
quite different orbit patterns and telemetry formats. 73 GM4IHJ @ GB7SAN