"Earl Kiosterud" wrote:



Robert,

Was AM radio ever allowed audio to 15 KHz? I read many years ago that it was, perhaps
before the NRSC recommendation was adopted by the FCC. I presumed that the stations either
were allowed to overlap 5 KHz (doubtful), or that stations in a given area were separated by
at least 30 KHz.


I'm not Robert, but...

Prior to FM multiplex stereo, there were some experimental stereo
broadcasters who transmitted one channel on FM and the other on AM. A
friend of mine has an old Lafayette tuner set up this way, along with
a plug-in jack for a multiplex adapter when they became available.

I think there was quite a large amount of effort to produce wideband
AM. Amplitude modulation itself certainly has no such limitations;
however it is possible that tuning the tower system to handle that
wide a bandwitdth within MW would be a problem. Don't know.


--
Eric F. Richards,
"It's the Din of iBiquity." -- Frank Dresser