[BC] Analog AM bandwidth: tail wagging the dog?

[Robert Orban]

At 06:19 PM 10/3/2007, you wrote:
>Bob Orban wrote:
> > I believe that a significant reason that the final preferred
> > bandwidth was 7 kHz was that broadcasting wider bandwidths puts more
> > stress on the audio processor. If the processor clips material
> > between 7 and 10 kHz (to which a vast majority of AM radios are
> > essentially deaf), the resulting clipping distortion products *will*
> > end up in the 0 to 3 kHz frequency and *will* be heard on typical
> > radios.
>
>That's all the more reason why audio above 6 kHz or so should be given its
>own band in the processor's multiband compressor/limiter structure, like
>your 9100 did, so that most of the HF gain control can be achieved before
>the audio hits the clipper(s).

This comment misses the point. If the transmission includes energy 
between 7 and 10 kHz, it takes up extra "room" in the modulation 
envelope. Getting a 0 - 10 kHz bandwidth transmission to sound as 
loud as a 0 - 7 kHz transmission on an average radio requires the 
audio to be clipped and limited harder, regardless of the details of 
how it is done in the audio processor.

bob Orban