"David Spain" wrote in message ...
Quite true. That's why most AM stations run lower power at night. At one
time the FCC (the manager of the airwaves in the USA) granted exception
to the so-called "clear channel" radio stations. Those used to be
distingushed by their special 3 letter call signs: WLS, WGN, WBZ, KGO,
etc. The "clear channel" station license allowed them to run maximum
power (50kW in the USA) 24/7 into an omni-directional antenna. Which at
night provided quite a distant signal. "Clear channel" meant they were
the only station authorized to transmit on that specific AM frequency in
the country. That was life back in the 60's and before. I don't know
where all this stands today. I lost track of it all near the end of the
80s. I believe I've read that "clear channel" exclusivity is a thing of
the past.

They still exist

https://en.wikipedia.org/wiki/Clear-channel_station, though it's a bit more
complicated.
And amazingly for 80 years XEW-AM in Mexico City broadcast at 250kW. I'm
surprised you couldn't cook hotdogs with that. ;-)


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Greg D. Moore http://greenmountainsoftware.wordpress.com/
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