Patrick Turner wrote:

I thought white noise had a rising amplitude as F rose.

as "burnt toast" as I am tonight - someone could claim white noise comes
from Procol Harum and pink noise from Pink Floyd - and I'd agree.

Here is the quote from the NRSC-1 spec for bandwidth testing - as it
relates to "source"...

Section: 6.3.2 Use of Standard Test Signal. Audio bandwidth shall be
measured using a test signal consisting of USASI (United States of
America Standards Institute) noise that is pulsed by frequency of 2.5 Hz
at a duty cycle of 12.5%. See Figure 4. USASI noise is intended to
simulate the long-term average spectra of typical audio program
material. Pulsing of the noise is intended to simulate audio transients
found in audio program Material. USASI noise is a white noise source
[note 4](i.e. noise with equal energy at all frequencies) that is
filtered by (1) a 100 Hz, 6 dB per octave high-pass network and (2) a
320 Hz, 6 dB per octave low-pass network. too Figure 4. A pulsed USASI
noise generator is shown in Figures 5 and 6. Using the attenuator pad,
the ratio of peak-to average amplitude shall be 20 db at the audio
output of the pulser. [snip]

Note 4. Acceptable white noise sources include GenRad Models 1382 and
1390B; Bruel & Kjaer Model 1405; and National Semiconductor IC No. MM5837N.

[end NRSC-1 quotes]

If you can find specs on any of those generators or that IC - then
you'll find what they think white noise is.

Right now it's approaching midnight - just went through the emotionally
draining experience of watching a old family friend's funeral on TV...
and Sherry and I are toast - so someone else can look them up.

best regards...
--
randy guttery

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com