Re: FM frequency response , possible above 15000hz ?

In article <pZ6dnQI7CdKe63zbnZ2dnUVZ_vihnZ2d@xxxxxxxxxxx>,
"Arny Krueger" <arnyk@xxxxxxxxxx> wrote:

"Don Pearce" <nospam@xxxxxxxxxx> wrote in message
news:46e46a39.1049448421@xxxxxxxxxxxxxxxx

The L-R signal is double sideband, centred on 38kHz. The noise
traverses the whole thing, but because of its slope, the noise on the
upper sideband is bigger than the noise on the lower sideband. The
noise traverses the lower sideband from high frequency to low, and the
upper sideband from low to high. So, because the noise in the upper
sideband is bigger, it wins.

I've done a drawing

http://81.174.169.10/odds/fm_noise.gif

I had to use a log frequency scale to get it all in and to allow me to
use a straight line for the phase noise.

For another viewpoint:

http://www.ham-radio.com/k6sti/monster.htm

For yet another viewpoint see this:

http://fmamradios.com/stereonoisecalc.txt

This is a computer program that calculates similar numbers to the above
site by directly evaluating the three equations that define the noise
contributions of the L+R sum signal, the lower sideband of the
difference signal, and the upper sideband of the difference signal,
these are respectively n1, n2, & n3 in the program.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/
.

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