OSCAR-11 Report

[Clive Wallis <clivew@xxxxxxxxxxxx>]

                OSCAR-11 REPORT    14 June 1998

During  the  period  16  May  to 14 June reasonable signals have been
received from the  145.826  MHz.   beacon.   The  satellite  was  not
monitored  between  27 May and 10 June.  However there is no evidence
of ground control operations, and it appears  to  have  been  another
uneventful period.

Telemetry nominal. The battery voltage  has  tended  to  rather  low,
averaging  13.5  volts,  with  one  value  of  13.2  volts  observed.

The internal temperatures have fallen by about 2.5C to 2.2C and  0.6C
for battery and telemetry electronics respectively.

A  single  WOD  survey  of channels 1, 2, 3, 61 (magnetometers) dated
19-March-98 has been transmitted.  A quick plot of  this  WOD  showed
reasonable   agreement   with  the  theoretical  field,  and  nominal
attitude.  Anyone using this survey should note the unusual  starting
time of 16:00:05 UTC.

Reports   of the OSCAR-11 mode-S beacon have been received from Roger
W3SZ, Jim AF9A, Micheal OH2AVE, and Jack W9JIU.

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:U2RPT26.CWV, to prevent duplication.

73 Clive G3CWV   g3cwv@amsat.org