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Re: Re: [sarex] What am I doing wrong...?]

Try this procedure;
Connect your scope (DC coupled) directly to an FM receiver's
discriminator. With a signal generator set "on-freq", adjust the scope
to be "zeroed", then offset the generator first plus 5 KHz and then
minus 5 KHz in frequency and adjust the scope for say, 1 KHz (or better
yet 1/2 KHz) per division resolution. Once that reference is properly
set, adjust your transmitter limiter circuit so that deviation does not
exceed +/- 5 KHz, then adjust your TNC so that it is modulated
comfortably just below limiting. (more is not better here!). (For the
purists: Obviously if narrowband channels are used, the deviation
limiting needs to be set accordingly.)

Guido wrote:
>I full agree with the need to set a correct TX deviation, but what is
>way (for an average ham...) to measure it ???
>I have a Tek 100 MHz scope, HP old (and nice:-) HF-VHF-SHF signal
>and frequency meter, and the usual shack stuff.
>Someone can explain a technically-correct procedure ?
                                                 thank in adwance, 73 de


Joe Leikhim K4SAT


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