Sorry for comming late to the party... This may be relevant:
http://phk.freebsd.dk/loran-c/CW/ The basic idea is that you use a high-rate ADC, something like 1MS/s and then you average into for instance a 1msec = 1.000 samples circular buffer. That gives you a very narrow comb filter for all frequencies which are a multiple of 1 kHz, and extracting the phase from, for instance the 60 kHz WWVB carrier will be trivial. In the example above, the buffer were w full second long, 1.000.000 samples, this reveals the per-second modulation of the carrier, and allows you to extract any (averaged) signal on an integral Hz carrier frequency. There are Arm chips out there now with 1MSPS*12bit ADCs that's plenty for this kind of stuff. (see also: http://phk.freebsd.dk/AducLoran/) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.