[aprssig] Deviation meters

Jim Campbell jim_c at bellsouth.net
Thu Apr 5 13:03:55 EDT 2007


Stephen,

The URL that you provided didn't work for me.  This one did:

http://wa8lmf.net/downloads/index.htm

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?
>>
>> John
>
>
>
> 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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