[BC] AM Stereo On A Mono Radio-FM Loudness

[RichardBJohnson at comcast.net]

According to the FCC Rules, the FCC is wrong. The FM deviation must
be measured using a Type Approved modulation monitor --period.

There are published methods of verifying the monitor's calibration
using the Bessel-null method. This is done with a steady-state tone.
The ballistics of the meter and the characteristics of the flasher are
defined by the rules on type-approval of monitors.

It doesn't matter if the modulation levels are WRONG! The idea
is that EVERYBODY must use the same RULES. It's rules-based,
not physics based.

That said, if somebody was able to push a new monitoring scheme
through the FCC, that allowed unfair competition, and it seems as
though that's what they did, then the FCC is simply wrong (again).

Note that 75 kHz deviation is purely arbitrary, a RULE. In fact, with
FM, the deviation has little to do with the bandwidth occupied!

Somebody, maybe even Armstrong, himself, decided upon a
deviation that could be handled with conventional receiver
circuitry. The rest is history. Even the channel-spacing is
arbitrary! No radio station will sound louder and, therefore
obtain an unfair competitive edge, as long as the same rules
are followed by all. That is precisely why there are rules
about modulation monitors.

--
Cheers,
Richard B. Johnson
Read about my book
http://www.LymanSchool.org


 -------------- Original message ----------------------
From: "Dana  Puopolo" <dpuopolo at usa.net>
> Interesting.
> At the NAB a few years ago, I was shown by the FCC how they measured it there.
> They took a lab grade FM tuner and connected it to an oscilloscope that was
> calibrated to the tuner for 100% modulation at their lab. After adjusting the
> directional antenna to eliminate multipath, they looked at the modulation
> peaks on the calibrated 'scope. Too many and you got a pink slip. That sure
> DOESN'T sound like using occupied bandwidth to me!
> 
> -D
> 
> ------ Original Message ------
> Received: Wed, 03 Oct 2007 01:46:39 PM EDT
> From: RADIO DOCTOR <lylehenry at fastmail.fm>
> To: "Broadcasters' Mailing List" <broadcast at radiolists.net>
> Subject: RE: [BC] AM Stereo On A Mono Radio-FM Loudness
> 
> On Wed, 3 Oct 2007, Dana  Puopolo wrote:
> 
> > For the life of me, I still fail to understand why the FCC doesn't use 
> > occupied bandwidth as opposed to peak deviation to measure broadcast 
> > FM modulation. Every other radio service does it that way!
> 
> A major group was testing FMeXtra this summer and the engineer told me 
> that they do use occupied bandwidth.  The FCC had been there some time 
> back and saw how they did it.  No pink ticket.
> 
> 
> ..Lyle, FMeXtra evangelist, in Los Angeles, CA     Cell: 213-880-4690
> -----------------------------------------------------------------------
>            Go digital on FM with FMeXtra!  http://fmextra.com
> Lyle Henry, CPBE  THE RADIO DOCTOR  K9DKW/K7OO  Silver Lake/Los Angeles
>   SCA Consultant, Contract Engr: Brazil, China, Mexico, Taiwan, SE Asia
>                          323-660-4690 Office/Home
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