[time-nuts] FMT

[Normand Martel]

--- John Ackermann N8UR <jra at febo.com> wrote:

> Hi Normand --
> 
> Your method is similar to mine, except that I use a
> much closer beat 
> note (usually less than 100 Hz) and use spectrum
> analyzer software and a 
> sound card to measure the beat note (in the form of
> the delta between 
> two traces on the waterfall display).

Well, you use long term DIGITAL techniques to track
probably to the µHz.. i simply use an ANALOG technique
to get down to a +/- 10 mHz resolution, and using a
higher beat frequency is simply more comfortable to
the eye (X-Y scope display). Also, my generator has a
100 Hz resolution, so i can only use 100 Hz multiple
beat notes.

> 
> I think one of the reasons this method works so well
> is that the FFT 
> effectively averages the signal over some time, and
> I use a tool in the 
> software to derive an average across all the FFT
> results.  That smooths 
> out the instantaneous variations that make real-time
> measurement such a 
> challenge.
> 
> John
> ----

Maybe some day!!

73 de Normand VE2UM



 
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