OSCAR-11 Report

[Clive Wallis <clivew@xxxxxxxxxxxx>]

                OSCAR-11 REPORT    16 February 1998

During the period January 14 to February 16 1998  good  signals  have
been  received  from  the 145.826 MHz.  beacon.  Three reports of the
S-band beacon have been received.  Masa, JA0BES  reports  signals  of
one  S point above the noise, using a 34 element beam, and Maki-Denk1
converter. Joe KC6SZY uses a 76 cm dish, with 2.5 turn  helical  feed
into  an  SSB  converter.  He reports S3 signals, comparded to DOVE's
S6.  Joe has very kindly sent me an audio file of the signals,  which
I  have  added to my web site (details below).  Ken G8VR also reports
hearing OSCAR-11 and DOVE on S band.

The   telemetry  is  nominal.   After  a  slight  fall  the  internal
temperatures have stabilised at around at 5.4C and 3.0C  for  battery
and  telemetry electronics respectively. The change in temperature is
due to variations solar eclipse times.  In recent years the satellite
has been subjected to long periods of continuous sunlight  which  has
produced  fairly  high  internal  temperatures  eg  battery  22C, and
beacons around 34C.  Eclipses are  expected  throughout  1998,  which
should result in lower temperatures, with fairly small variations.

A single WOD survey has been transmitted during the period.  Channels
10,  20, 30, 40 ( +Y, -X, +X array currents, array voltage), dated 06
January.  This shows the effect of solar eclipses, on array currents,
and voltage.

OSCAR-11  users  are  welcome  to  visit my web site. I have recently
added some audio files, including the Mode-S recording  from  KC6SZY,
which  plays  for  20 seconds.  The other audio files are examples of
each type of data transmitted by OSCAR-11, and  each  one  plays  for
about  ten  seconds. All the audio files are zipped, so that they can
be played off-line.  They should help listeners identify the  various
types  of data, and give an indication of the signal quality required
for successful decoding.  The web site also  contains  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. The URL is -

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


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)

There  are  also  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.

If you place this bulletin on a terrestrial  packet  network,  please
use the bulletin identifier $BID:U2RPT22.CWV, to prevent duplication.

73 Clive G3CWV   g3cwv@amsat.org