OSCAR-11 Report December 2011

Oscar 11 being built

Oscar 11

Clive Wallis G3CWV provides an update on the UK Amateur Radio satellite Oscar 11 which has completed nearly 28 years in orbit.

This report covers the period from September  1 to December 28 2011.

The satellite has continued to operate in a very predictable way since the last report, and no changes have been observed. During this time the satellite has been heard reliably during its ten-day transmission periods. Excellent signals have been reported from stations located around the world, and good copy obtained from decoded telemetry frames.

The easiest way to check whether OSCAR-11 is operational is to look at the General Satellite Status website http://oscar.dcarr.org/index.php . You can also calculate the operating schedule from the last switch-off time, which was December 28, 2011 at 15:00 UTC (approx), using 10.35 days off followed by 10.35 days on.

Reception reports have been received from Gustavo LW2DTZ, Bob KI0G, Rolf HB9TSO and Francesco IT9JRU.  Many thanks to all and those who posted to the status website.

The satellite is currently in eclipse during all evening passes over the UK, resulting in lower signal strengths at these times.  Owing to the gradual precession of the orbit, the season for eclipses of the evening passes is longer this year compared with the winter last year.

The on-board clock continues to gain, 28 seconds during the current reporting period, and 112 seconds since regular transmissions were resumed at the end of August 2010. There is however a large accumulated error of 308.54303 days slow. This was caused mainly by the clock stopping during eclipses, when there was also an unknown drain on the power supply. The units of the least significant digit correspond approximately to seconds (0.86 seconds actually).

The VHF beacon frequency is 145.826 MHz.  AFSK FM ASCII Telemetry. The satellite is operating in the default mode, with a cycle time of 20.7 days. 10.35 days on followed by 10.35 days off.

At the present time, while OSCAR-11 is operating in a predictable way, I no longer need direct reports or files by e-mail. However, could all listeners continue to enter their reports on the general satellite status website. This is a very convenient and easy to use facility, which shows the
current status of all the amateur satellites, and is of use to everyone. Reports around the expected times of switch-on and switch-off are of special interest, especially for times 12:00 – 18:00 and 22:00 – 07:00 UTC, when the satellite is out-of-range in the UK . The URL is http://oscar.dcarr.org/index.php

A longer version of this report report is available on my website, and new listeners to OSCAR-11 should read this for further information. The URL is http://www.g3cwv.co.uk/oscar11.htm
This page contains a links to the longer report, a short audio clip to help you identify the satellite and a file of the last telemetry received. The website also contains an archive of news & telemetry data which is updated from time to time, and details about using a soundcard or hardware demodulators for data capture. There is also software for capturing data, and decoding ASCII telemetry.

If you place this bulletin on a terrestrial packet network, please use the bulletin identifier $BID:U2RPT157.CWV, to prevent duplication.

73 Clive G3CWV xxxxx@amsat.org (please replace the x’s by g3cwv)

AMSAT-UK publishes a colour A4 newsletter, OSCAR News, which is full of Amateur Satellite information. Free sample issue at http://www.uk.amsat.org/on_193_final.pdf Join online at http://tinyurl.com/JoinAMSAT-UK