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OSCAR-11 Report







                OSCAR-11 REPORT    15 December 1998

The current duration of solar eclipse time has continued to provide
OSCAR-11 with near optimum conditions, maintaining an adequate power
budget, while not allowing internal temperatures to rise to excessive
levels. During the period 15-November to 16-December reasonable
signals have been received from the 145.826 MHz. beacon. Telemetry
nominal. The battery voltage is now usually around 13.9 volts.

The magnetorquer spin correction counters have continued to be of
interest.  Recently there have been very few spin counter increments,
although the spin period remains around its nominal value of -300
seconds.

The internal temperatures have fallen slightly, by about one degree C
after reaching a peak last month. They are now 9.0C and 7.0C for
battery and telemetry electronics respectively.

The single WOD survey, of channels 1, 2, 3, 61 (magnetometers) dated
10-October 1998, has continued to be transmitted.  This current WOD
starts at the normal time of 0:0:5 UTC.

Reports have been received of the mode-S beacon from Jack W9JIU and
Victor Ok1VKW.  Victor uses a 40 element horizontally polarised Yagi
with an SSB converter. Signal strengths are S1 - S2, about 10 dB
above noise.  Many thanks for those reports.

The operating schedule is unchanged.

        ASCII status (210 seconds)
        ASCII bulletin  (60 seconds)
        BINARY SEU (30 seconds)
        ASCII TLM (90 seconds)
        ASCII WOD (120 seconds)
        ASCII bulletin (60 seconds)
        BINARY ENG (30 seconds)

The ASCII bulletin is currently a static message, detailing modes and
frequencies of all the amateur radio satellites.

There  are  additional  status  blocks  after  each bulletin is
transmitted, and between ASCII TLM and WOD.

The mode-S beacon is ON, transmitting an unmodulated carrier, but
telemetry indicates that it has partially failed, and delivering half
power.  This beacon is a useful test source for those testing mode-S
converters, prior to the launch of P3-D.  It is considerably weaker
than DOVE, which should be used for initial testing. Any reports of
reception on 2401 MHz.  would be most welcome.  Please e-mail
g3cwv@amsat.org.

The 435.025 MHz. beacon is normally OFF.  However it can sometimes be
heard when the satellite is being commanded by ground control, ie.
within range of Guildford, UK.  When the 435 beacon is transmitting,
the 145 beacon is normally OFF.  The data transmitted is mainly
binary.

Listeners to OSCAR-11 may be interested in visiting my web site.  The
web site contains details of hardware required and some software for
capturing data, and decoding ASCII telemetry and WOD.  There is an
archive of raw data (mainly WOD) for analysis, which is continually
being expanded, as new data is captured.  Also included are some
audio files, examples of each type of data transmitted by OSCAR-11,
each one plays for about ten seconds.  There are also examples of
mode-S reception.  All the audio files are zipped, so that they can
be played off-line.  These should help listeners identify the various
types of data, and give an indication of the signal quality required
for successful decoding.

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:U2RPT32.CWV, to prevent duplication.

73 Clive G3CWV   g3cwv@amsat.org



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