The ARRL doesn't have the faintest idea of anything
above 30 MHz, much less FM.
The 5 kHz deviation, for most amateur repeaters these
days, is definitely a peak deviation, or as you
mentioned, p-p / 2. Most deviation meters are
calibrated for peak deviation.
You could use an AC RMS voltmeter to measure recovered
audio on another receiver, but the deviation would
only be meaningful if fed with a sinusoidal signal.
Bob M.
======
--- [EMAIL PROTECTED] wrote:
> I agree. DTMF is two sinusoids. You don't want the
> limiting action to distort the signal. BTW this is
> also why you should use 3KHz as a baseline on linked
> systems to keep the audio as linear as possible
> through chain-linked RF repeaters.
>
> One thing that bugs me though is that the 2005 ARRL
> handbook says 5KHz RMS deviation (appx 7.07 KHz) for
> NBFM. I beleive this is wrong. I've always used
> peak-to-peak/2 setting on the HP8920 service
> monitor.
>
> Carson's rule states that channel bandwith is 2
> times the sum of the peak deviation and highest
> modulating frequency. If you use 5 KHz RMS deviation
> with a 1KHz sinusoid, the channel bandwidth will be
> 2*((1.414*5000)+3000) = 20.14KHz!
> This ain't 16K0F3E.
>
> Steve
> WA6ZFT
>
>
> >
> > From: mch <[EMAIL PROTECTED]>
> > Date: 2005/12/02 Fri PM 02:43:24 PST
> > To: Repeater-Builder@yahoogroups.com
> > Subject: Re: [Repeater-Builder] Deviation
> >
> > TT should be between 3 and 4 kHz deviation.
> (preferably closer to 3)
> >
> > Joe M.
> >
> > Charles Greene wrote:
> > >
> > > Ken,
> > >
> > > Shouldn't the touch tone pad tone be set at the
> maximum deviation or
> > > nearly so? Those are steady and not subject to
> peaks. Also I take
> > > it the max deviation should be set with a 1Khz
> audio tone applied>
> > >
> > > 73, Chas W1CG
> > >
> > > At 05:05 PM 12/2/2005, you wrote:
> > > >One thing that hasn't been mentioned so far,
> and one thing that is quite
> > > >important, is that regardless of the suggestion
> of 5 or 4.75 Khz, it must
> > > >be noted that these are PEAK values, not
> average.
> > > >
> > > >If the average deviation is set for 5 KHz, then
> the peaks will be
> > > >absolutely be more than 5 Khz.
> > > >
> > > >So use the scope in the service monitor, not
> the meter
> > > >
> > > >Ken
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