Patrick Turner wrote:

Would not the use of pink noise through a low pass filter
and used as the carrier signal modulation be a better way to see the
frequency contour on an analyser, why noise + piano?

Absolutely - then you "know" what you're looking at.

Actually the NRSC (I know Patrick -you guys don't have to fool with
such) specifies a white noise source (equal energy at all frequencies)
filtered* then gated at 2.5hz with a 12.5% duty cycle. This is felt to
best simulate "real world" broadcasting. Again see the NRSC-1 spec I
noted yesterday.

*filter is 100hz high pass 6db/octave and 320hz low pass 6db/octave.
(yes that's -36db @ 10.24khz)

best regards...
--
randy guttery

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