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Fox Telemetry Decoder Software Now Available


AMSAT has announced that FoxTelem ver 1.0 software, the Fox Telemetry Decoder, has been released so stations can start setting up, testing, and debugging their ground stations prior to the October 8 launch of the Fox-1A satellite. FoxTelem is used to demodulate, store, and analyze telemetry data from AMSAT’s Fox series of CubeSats. Until Fox-1A launches, users can confirm that everything is working by using a test WAV file, available from AMSAT.

Fox-1A will include an FM transponder with an uplink frequency of 435.180 MHz, and a downlink frequency of 145.980 MHz. The first phase of the Fox series 1-Unit CubeSats will allow simple ground stations using hand-held transceiver and simple dual-band antennas to make contacts. The Fox CubeSats also will be able to transmit continuous telemetry during normal transponder operation.

Fox-1 satellites will employ two telemetry formats. Slow Speed, also called Data Under Voice (DUV), is 200 bps FSK data, sent at the same time as the transponder audio at a frequency below 300 Hz. Whenever the transmitter is on, data are being sent, even during beacons and live contacts. High Speed is 9600 bps FSK that will be sent instead of the transponder for data-intensive experiments, such as the Virginia Tech Camera. This will only be active when commanded from the ground, and it will sound “like an old-school computer modem,” said Chris E. Thompson, G0KLA, in announcing the software release.

FoxTelem will receive and store both formats, assuming you can feed it audio that does not filter frequencies below 200 Hz. For High Speed, the audio must also extend to include the full 9600 bps bandwidth of the FM signal. For both modes this is best achieved by using a Software Defined Radio or from the 9600 bps packet port of some radios. The FoxTelem User Guide provides more details. — Thanks to AMSAT