[amsat-bb] Re: ARRISat-1 CW

Phil Karn karn at philkarn.net
Tue Apr 12 21:32:50 PDT 2011

Right, it's conventional CW, mode A1, with the carrier switching on and off.
A2 would be considerably less power-efficient.

ARISSat-1 also uses the CW beacon as a tuning reference for the BPSK-1000
digital beacon. The BPSK beacon is centered 1 kHz above the CW beacon so
that the CW beacon sits in the lower spectral null of the BPSK signal, i.e.,
in a narrow spot where there's no BPSK signal power.

If you put your receiver in USB mode and tune the CW beacon so it comes out
at an audio frequency of 500 Hz, this will automatically center the BPSK
signal in a conventional SSB filter extending from 300-2700 Hz.

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