RE: [Discuss-gnuradio] Demo Audio Code

[Joseph DiVerdi]

At 10:35 AM -0800 3/5/03, Ettus, Matt wrote:
>> http://xtrsystems.com/vlf/image/wwvb_xy - WWVB real and 
>> imaginary channels plotted against each other (my personal favorite)
>
>
>My favorite too!  All you need is a good pll, and you can get those cool
>looking circles to look like some not-as-cool-looking-but-way-more-useful
>dots.  Then you could just use a simple data slicer to get the data, and the
>PLL frequency would give you your frequency info.
>
>See src/gnu/lib/dtv/GrAtscFPLL.[cc,h] for some sample code.  You might even
>be able to use it as is.  It was developed for an 8-PAM system, but will
>perform even better for an ASK system since the signal is unipolar.  You may
>need to tweak the gains.
>
>Matt

Dear Matt,

Thanks for the code tip. I will look into it but not for WWVB. There is not 
phase/frequency modulation on WWVB only the two-level ASK. (So admittedly there 
would be two dots.) The timing of the levels carries a binary time code. The 
carrier frequency can also be used as a potentially very accurate 
phase/frequency reference with the customary limitations on atmospheric 
propagation. For my location (only a few miles from the transmitter) it is very 
good.

Soon, I hope to be generating such data using only gnu-radio tools and goodies.

Best regards,
Joseph
-- 
Joseph A. DiVerdi, Ph.D., M.B.A.          
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