[time-nuts] DSP WWVB Receiver Idea
Poul-Henning Kamp
phk at phk.freebsd.dk
Tue Apr 21 21:21:19 UTC 2009
In message <49EE3568.3000907 at pacific.net>, Brooke Clarke writes:
>On the PICLIST there has been a discussion about the CMAX WWVB front ends and
>noise. Olin mentioned that you could use a dsPIC to look at the I and Q
>signals resulting from mixing the WWVB signal with a carrier at 60 kHz. His
>example case was to use a cheap crystal (+ or - 3 Hz) and so use a 10 Hz low
>pass filter on the I and Q signals prior to squaring and adding them.
Don't bother with I & Q, put an ADC directly on your antenna and do it
in software.
See http://phk.freebsd.dk/AducLoran for inspiration.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at 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.
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