[aprssig] Deviation meters
jim_c at bellsouth.net
Thu Apr 5 12:03:55 CDT 2007
The URL that you provided didn't work for me. This one did:
Tnx es 73,
Jim - W4BQP
Stephen H. Smith wrote:
> johnk.mchugh at att.net wrote:
>> The Bezzel function for the first carrier null is 2.405. The formula
>> is (Required Dev/ 2.405). So if you want to set the deviation to
>> 3.5KHz, use an audio tone of 3.5/2.405 or 1.455KHz. Oh, you don't
>> have a 1.455KHz tone, then use the mark tone from a KAM, usually
>> 1600Hz on HF. There must be software that will produce variable audio
>> tones from a sound card, anyone know of such a program?
> The freeware utility bundle "Wavetools" on my web site downloads page
> will do this.
> It bundles 4 applications that use the sound card: an audio function
> generator, an audio level (a.k.a. "V.U.) meter, a dual trace scope and
> an audio spectrum analyzer.
> Go to < http://wa8lmf.com/miscinfo > and look for the file
> "Wavetools.exe" near the bottom of the list.
> By the way, it's Bessel , not Bezzel . Incidentally, the
> traditional RTTY mark tone of 2125 Hz produces a Bessel null at 5.1
> KHz deviation.
> Stephen H. Smith wa8lmf (at) aol.com
> EchoLink Node: 14400 [Think bottom of the 2M band]
> Home Page: http://wa8lmf.com --OR-- http://wa8lmf.net
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