OSCAR-11 REPORT
16 June 2007
During the period 15 May to 15 June 2007, no signals have been received from the satellite's 145.826 MHz. beacon. I have not received any reception reports.
The satellite is currently subject to solar eclipses, which will continue until 20 August. The duration of the eclipses has now reached its maximum time of 23 minutes and will now start to decrease.
The battery can no longer power the satellite during the eclipse season. When the battery voltage decreases to a preset level, the watchdog timer resets, and the beacon is turned off for approximately 21 days. When the satellite restarts, eclipses could cause the beacon to switch OFF, after a short time, probably less than one orbit. This short transmission could occur any where over the world, and could be repeated at 20.7 day intervals.
Owing to the lack of accurate timings, it is impossible to predict when and where the satellite will be heard during these short transmission periods. It is just possible that someone tuning around 145.826 MHz. may hear the satellite, by chance.
Observations during the last period of sustained operation (22 to 28 April) showed that the satellite could survive eclipses below 12 minutes duration. This means that sustained transmissions could start any time after 10 August, when then eclipse duration will have decreased to below 12 minutes. However, if the satellite had switched off just before 10 August, sustained operation could be delayed until the end of August.
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. The current monthly bulletin contains further details of the satellite's status. If you need to know what OSCAR-11 should sound like, there is a short audio clip for you to hear. The website 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:U2RPT134.CWV, to prevent duplication.
73 Clive G3CWV xxxxx@amsat.org (please replace xxxxx by g3cwv)