[time-nuts] VLF Phase-tracking receivers.
ve3oat at storm.ca
Sun Aug 10 15:24:16 EDT 2014
As I recall (it was a long time ago), it was called Minimum Shift
Keying and used the minimum frequency shift (FSK) that would permit
reliable detection of a bit (mark or space) at the given information
rate. Something like 25 Hz shift at 50 baud keying. But it was
necessary to control the instantaneous phase of the signal very
carefully. As a result the spectrum of an MSK signal is quite
distinct from that of an ordinary FSK signal. As I recall.
... Martin VE3OAT
Ken W7EKB wrote :
> As I understand it from back in the 1970s when I was first working on this
> sort of thing, the modulation is not FSK, but "MSK" (whatever that is) at
> something like 25 to 50 Hz, ... (snip)
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