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OSCAR-11 Report



                  OSCAR-11 REPORT

                  24 January 2006

Users of OSCAR-11 may be interested in recent additions to my website.
Firstly UCAP, this is a simple OSCAR-11 capture program for Windows, and
may be used instead of CTERM. It features an accurate time stamp facility,
which is useful for checking the satellite's real time clock.

Secondly, the news and telemetry archives have been updated to include all
the 2005 data.  The URL is www.users.zetnet.co.uk/clivew

During the period 14 December 2005 to 23 January 2006 the VHF beacon on
145.826 MHz. has been heard from 23 to 31 December and from 11 to 21
January.

Signals during the December passes were very variable. Sometimes received
at good strength, at other times they were inaudible , even with the BFO
switched ON (ie. in CW mode). Signals during the January passes tended to
be much stronger, and good copy was obtained on most passes.

The on-board clock continues to accumulate a very large error. On 21
January it was 22.14 days slow, having lost 0.33 days (8 hours) since 09
December. However, the rate of change of clock error appears to vary
between zero and half an hour per day, over short periods. The greatest
changes seem to correspond with poor signals, which suggests that the clock
may slow or stop when the battery voltage is low.

All the analogue telemetry channels, 0 to 59 are zero, ie they have
failed.  The status channels 60 to 67 are still working.

The satellite is now in continuous sunlight until around 06 May, when
eclipses will start again. This should help the satellite to continue
transmitting, although continuous sunlight can cause problems due to
excessive temperatures. Power supply problems can be caused by poor
pointing attitude, ie the sunlight illuminating the ends of the satellite,
instead of the solar arrays.

The watchdog timer now appears to have resumed operation on the 20 day
cycle, ie. approximately ten days ON followed by 10 days OFF. However, at
any time, poor solar attitude, and battery problems, may result in a low 14
volt line supply, which may cause the beacon to switch OFF prematurely, and
reset the watchdog timer cycle.

The Beacon frequencies are -

VHF 145.826 MHz.  AFSK FM  ASCII Telemetry

UHF 435.025 MHz.  OFF

S-band 2401.5 MHz. OFF

Listeners to OSCAR-11 may be interested in visiting my website which
contains an archive of news & telemetry data. It also contains details
about using a soundcard or hardware demodulators for data capture.  There
is software for capturing data, and decoding ASCII telemetry.  The URL is
www.users.zetnet.co.uk/clivew/

If you place this bulletin on a terrestrial packet network, please
use the bulletin identifier $BID:U2RPT117.CWV, to prevent duplication.

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