[time-nuts] FMT
Normand Martel
martelno at yahoo.com
Wed Nov 15 11:06:05 UTC 2006
--- 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
____________________________________________________________________________________
Cheap talk?
Check out Yahoo! Messenger's low PC-to-Phone call rates.
http://voice.yahoo.com
More information about the Time-nuts_lists.febo.com
mailing list