[time-nuts] WWVB BPSK Receiver Project?

[Poul-Henning Kamp]

In message <4F6116CE.7080809 at pacific.net>, Brooke Clarke writes:

>I sure would like a WWVB BPSK receiver for the new modulation. 

I've been playing with SDR and VLF signals for ages.  What you
want is an antenna, a 1MSPS ADC and a fast-ish CPU.

One very interesting thing you can do with that, is to make a
buffer 1000 samples long, and continously average the received
signal into it, round-robin format.

That amounts to a comb-filter for every n*1kHz signal, and a
trivial sin/cos multiplicator will give you the phase and
amplitude of every single radiotransmitter on n*1kHz up to
your antialias filter at the same time.

If you have CPU power, you can also receive Loran-C by making the
buffer GRI*10 (or *20, if you want the code) samples long.

I've long thought about building a board with one of the faster
ARM CPUs and a 1MSPS 16bit ADC for this, but nobody else seemed
interested, so I've just used my hacked up rig.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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Never attribute to malice what can adequately be explained by incompetence.