[BC] AM Fidelity vs FM fidelity

[Kevin Raper]

On Jun 21, 2012, at 12:28 PM, Jim Tonne wrote:

>That receiver, and all the junk (including path problems such as noise) 
>between it
>and the transmitter, clearly enters into the picture in the real world.

Yes and having a good receiver makes a huge difference. Before NRSC came along, my Carver TX-11a tuner sounded better on AM then FM on Simulcasts. It was easy to tell what stations put in their NRSC filters as slowly the band turned into muddy audio. On My station, it went from Sparkle to Mush when I replaced the CBS Audimax and Volumax with a CRL AM-4 Chain into a Modified CCA AM-1000D. Yea, those CBS boxes are now on my 160 Meter rig :-)

You could also hear the difference between the old DAP-310 and the Optimod 9100A at another station I worked for. It also went to mush when I had to replace the 12 KHz filter with the NRSC filter. That station had a SX-1 that I put a SX-1A PA board in it.

FM Stereo, on the other hand has a 15 KHz Brick wall filter to keep the audio out of the Pilot.

73,
Kevin Raper
KJ4HYD
CE WCKI WQIZ WLTQ