Auke de Jong, VE6PWN wrote:

Just a quick query regarding UO-11's Mode-S beacon at 2401.5.

In a couple of places I have read that the Mode-S beacon is said to "transmit continuously", while others list that beacon as "non-operational". I have also noticed that it is listed a few times as having been heard(telemetry only) on the "oscar.dcarr.org" site inside their database, using Mode-S.

I am wondering if it is worthwhile to listen for this beacon (using my newly installed BBQ-grid antenna), or is it definitely not making any noise?

The mode-S beacon is OFF, and has not been heard for many years. The status telemetry indicates that only the VHF beacon is ON.

When the mode-S beacon was active, it did transmit continuously, a steady carrier, very weak, with lots of Doppler. A trace of telemetry modulation has been detected, although this may have been due to accidental coupling within the satellite.

If you look on my website, www.g3cwv.co.uk there is an audio clip of what it sounded like and a spectro-gram of the signal. The news archive gives details of when it was transmitting mode-S.

HTH

73 Clive G3CWV

Hitchin, North Hertfordshire, UK