In article , Bill Taylor
scribeth thus
On Thu, 2 Feb 2017 00:22:39 +0000, tony sayer
wrote:

In article , Max
Demian scribeth thus
On 01/02/2017 17:01, Dave Plowman (News) wrote:
In article ,
RobertL wrote:
On Wednesday, January 18, 2017 at 12:50:08 AM UTC, Dave Plowman (News)
wrote:
In article , NY
wrote:

It is generally accepted that human hearing is 20-20,000 Hz
(https://en.wikipedia.org/wiki/Hearing_range and many other sources)
and diminishes with age.

For those who go on about how good FM radio is they should note it
doesn't go anywhere near 20 kHz. ;-)

It goes to 16 kHz which is quite close.

They chose to cut it there so they coudl fit in eth 19 kHz pilot tone
and then use the bandwidth up to 38 kHz for th stereo difference signal.

Yup. They degraded the mono performance to squeeze in stereo. Nothing new
under the sun.

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.

Made not a lot of odds the S/N is very good anyway assuming, and this is
the bit that rarely happens anymore, a decent input signal i.e. roof
aerial and all that..

Quite right about the studio to TX feeds the signals were very much up
to what the olde postal orifice could manage;!..


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.

Thats a much wider illness nowadays than radio;(..
--
Tony Sayer