[time-nuts] WWVB phase modulation format?

John Seamons jks at jks.com
Sun Mar 11 18:53:42 UTC 2012


On Mar 9, 2012, at 4:28 PM, Peter Monta wrote:

> Interesting that WWVB is running a phase-modulation test---thanks for
> the links.  Is the signal format known?  A quick search shows nothing
> specific, just "we're testing".
> 
> Could someone record a few minutes of the broadband signal so that
> those of us without ready-to-hand LF receivers can have a look?
> 
> Cheers,
> Peter

I took a look at this. Pictures and video here: http://jks.com

I believe what they were doing is applying a simple 180 deg phase shift to the carrier (BPSK) during certain one second timecode intervals.
Whether there was anything fancier going on or not (like what DCF77 does) I couldn't tell immediately, although I did make a 192 ksps sound card recording for future analysis.

Apologies for the crude measurement and presentation. I had to throw this together in a hurry.





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