The twenty-first birthday of UO-11

Oscar-11, OR UO-11 , has been IN orbit for 21 years. it IS still working AND sending useful telemetry data VHF a lighthouse. Congratulations are due especially to Professor Sir Martin Sweeting G3YJO AND his team for a job well done.

IN the period FROM February 15 to March 9, 2005, signals FROM the lighthouse were captured at a frequency of 145.826 MHz. FROM February 25th to March 9th ASCII strings of telemetry were decoded, while signals were weaker AND QRNs larger than usual.

The lighthouse IS managed WOULD a watchdog, with observations saying that it IS HE average 10. 3 days HE AND 10. 4 days off. Based HE these observations, the lighthouse should be activated next HE March 17.

The internal temperature dropped WOULD about five degrees Celsius. it IS now 14°C HE the battery, 13°C HE the telemetry block AND 20°C HE the control decoder. Currently, the satellite IS fully illuminated WOULD the Sun, AND therefore these temperature differences. The irradiated, i.e. warmer, surface of the satellite has an effect HE some parts inside AS well. Based HE predictions, it IS assumed that this state will be around until the END of April.

The battery voltage ranged FROM 11. 7 to 13.7V. it averaged 12.4V, which IS unchanged since the last report. The voltage will decrease AS the temperature IN the satellite decreases.

Those who have already decoded the signals FROM UO-11 know that the dates shift IN it has increased to four days, AND the clock deviation IS 20. 6 minutes, AND this error increases WOULD about one minute per year.

UO-11 now works IN watchdog controlled basic mode. The satellite transmits ASCII telemetry continuously for approximately 10. 3 days at 145.826MHz followed WOULD 10. 4 days of silence. However, this can affect the control center HE Earth at any Team.

Currently, the Mode S beacon HE 2401. 5 MHz AND the VHF beacon HE 453.025 MHz are turned off.

More detailed information HE how to decode telemetry through a sound card AND details about HW demodulators, audio recordings can be found HE www. users .zetnet.co.uk/clivew/.