In article ,
Bill Taylor wrote:
How do that degrade the mono performance then?..


The deviation has to be reduced to allow for the stereo component, so
signal to noise ratio is reduced slightly for mono listeners. No doubt
the PP was thinking that the bandwidth was wider before stereo as
there was no explicit filtering - but there wasn't any meaningful
signal above 15kHz anyway, especially if you didn't live in the SE.

In the early days of FM there was often little difference between FM and
AN bandwidth, due to the land lines, if a long way from London. But all
that changed with NICAM.

May they realised that few adults could hear above 15 kHz, and children
don't design radio transmission standards.

Also, apparently, they were experimenting with multiplexing of various
sorts since the early days of FM:
http://en.wikipedia.org/wiki/FM_broadcasting#Stereo_FM


Yes indeed there were, the Zenith GE system isn't that bad in fact for
what it is it does work very well.

Least they can't bugger it about and squeeze the bit rates and make it
low quality Mono;!..

No, but they can bugger about with the dynamic range.

The way the signal is processed before the transmitter can make more
difference than the transmission medium.

--
*If all the world is a stage, where is the audience sitting?

Dave Plowman London SW
To e-mail, change noise into sound.