[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.

More information about the time-nuts mailing list