[BC] AM HD power levels

[Phil Alexander]

In AM we have something called NRSC-2 a/k/a Sec. 73.44(a).
That rule prohibits anything approaching good quality.
50 years ago both AM and FM stations were routinely 
transmitting audio from 30 - 15,000 Hz. WLW was certified
by MacIntosh as transmitting 20 - 20,000 Hz at very low
distortion. Today we have technology making AM capable of
transmission beyond that, but alas, stereo prevents FM
from duplicating this feat.

50 years ago, a tuner from Fisher or Sherwood could
reproduce those signals beautifully. This was the meaning 
of HIGH Fidelity. By comparison, what we have today can't 
come close because, since the advent of stereo, nobody
cares.

In 1965 much of the performance we seem to think is good
would have been considered unacceptable, except for the
reduction of noise that silicon brought.

Poor quality is what sells today. That is why it is made.

And BTW, solid state was a toy for experimenters 50 years
ago. I know, I built a code practice oscillator with a
Raytheon CK722 about 1952. The performance we got, we got
with TUBES, not because they were better, but because they
were all we had.


---------------------------------------------
Phil Alexander, CSRE, AMD
Broadcast Engineering Services and Technology 
(a Div. of Advanced Parts Corporation) 
Ph. (317) 335-2065   FAX (317) 335-9037


On 30 Aug 2008 at 18:10, Kevin Tekel wrote:

> Of course AM stations -- at least those not transmitting IBOC -- are still
> putting out excellent signals with superb audio quality.  It's the poor
> quality of receivers that is at fault.