Transmissions were reported also from satellites in geosynchronous orbit but they were not detectable in the UK because the satellites in question are below the local horizon. There are unsubstantiated reports that the uplinks could be intercepted in some parts of the continental United States. AFSATCOM transmissions (from HEO at least) ceased in 2008.

The AFSATCOM bandplan consists of rwelve channels, each with specified frequencies for the uplink and downlink. When it a signal is received on the uplink, it is shifted down by a set amount (72.900 MHz) and retransmitted.

The bandplan is formed symmetrically. The first two and last two channels (numbers 1/2 and 11/12) have a spacing of 10 kHz between them. The remaining channels are each 5 kHz from their neighbours.

The frequency pairings are:

The content of the signal signal transmitted from the satellite is reversed compared with the signal that was received. A channel with nothing on its uplink is transmitted as a CW tone so it is possible to distinguish between an empty channel and a non-transmitting one. As of 2006 June, downlink channels 1-8 and 10-12 were carrying RTTY links, some with frequency shift of approximately 2.7 kHz and some with approximately 2.1 kHz. Channel 9 had a single carrier, making it very useful for measuring the Doppler shift.

From time to time, the transmit frequency is shifted downwards (approx 168 second intervals) by about 20 Hz in order to counteract the changing Doppler shift experienced by ground stations.

There is a detailed description of how AFSATCOM was working in the Satellite Tracking area of the Zarya web site and it can be found by following the link in the right hand menu.