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OSCAR-11 Report



                  OSCAR-11 REPORT

                   25 May 2005

This report covers the period 18 April to 24 May 2005.

OSCAR-11 resumed transmissions on April 28, after its ten day period of
silence. The telemetry showed that ALL the analogue channels were zero,
although the status channels were normal.

The on-board clock was five hours slow.

Signals were fairly good, although at the present time, I cannot track the
satellite accurately owing to a stuck elevation rotator!

Good signals were also received on 30 April, with all the telemetry
channels showing zero values. The on-board clock was 4.45 hours slow.

Sometime between  30 April and 02 May the satellite switched OFF. This
coincided with the start of the solar eclipse season, which started on 27
April, reaching 10% of the orbit time by 02 May.

Nothing heard on 18 May when the satellite might have been expected to
resume transmissions. However, on 19 May Gustavo LW2DTZ (located near
Buenos Aries) reported hearing good signals at 22:11 UTC.  Many thanks
Gustavo for that report.

It is possible that the satellite may still be controlled by the watchdog
timer, 10.3 days ON followed by 10.4 days OFF. Perhaps the eclipses may
cause the satellite to switch OFF early, after a day or two, when the
battery voltage is too low to operate the system.

If this theory is correct, the satellite might resume transmissions around
08 June, for a day or two. Commands from ground control could also affect
operation times.

The solar eclipses should reach maximum duration of 23% orbit time in
mid-June. The eclipses should finish in mid-August, when the satellite
enters a period of continuous sunlight for the remainder of the year.

Any reception reports would be appreciated.  Please send to me direct
g3cwv@amsat.org, or post to post to AMSAT-BB.

The Beacon frequencies are -

VHF 145.826 MHz.  AFSK FM  ASCII Telemetry - Occasional operation?

UHF 435.025 MHz.  OFF

S-band 2401.5 MHz. OFF


Here is a sample frame of telemetry from the 05:46 pass on Thursday 28th.


UOSAT-2           0505024014454

000000010001020002030003040004050005060006070007080008090009
100001110000120003130002140005150004160007170006180009190008
20000221000322000023000124000625000726000427000528000A29000B
30000331000232000133000034000735000636000537000438000B39000A
40000441000542000643000744000045000146000247000348000C49000D
50000551000452000753000654000155000056000357000258000D59000C
60800E615FC1620141633341644402651E0C6630A967000168000E69000F



Listeners to OSCAR-11 may be interested in visiting my web site. This
contains an archive of telemetry data, including all the data received for
2005.

The web site contains details about using a soundcard for data
capture, and also details about using hardware demodulators. There is
software for capturing data, and decoding ASCII telemetry.

The URL is -

      http://www.users.zetnet.co.uk/clivew/

If you place this bulletin on a terrestrial packet network, please
use the bulletin identifier $BID:U2RPT109.CWV, to prevent duplication.

73 Clive G3CWV   g3cwv@amsat.org
----
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