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Old July 12th 06, 01:01 PM posted to rec.radio.shortwave
[email protected] shoppa@trailing-edge.com is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 21
Default Getting local AM station engineering aware of harmonic problems


Slow Code wrote:
wrote in
oups.com:

I have a local MW station (630 WMAL) that is radiating harmonics (1260,
1.890, etc.) on up the spectrum.

The harmonics are strong enough that 1260 AM (also a local station) is
unlistenable for about a mile surrounding WMAL's towers. It's also an
irritation throughout the SW bands.

I am rather certain that the harmonics are coming out of the
transmitter and not the result of local rectification (near or in the
receiver) because building a trap for 630kHz has no effect on the
harmonic and the harmonic is present over a very wide area.

My first attempts (calling the station, writing a letter) have been met
with no acknowledgment that there is a problem (it is not even obvious
that anyone understands that there MIGHT be a technical issue to pass
on to engineering.)

Any advice?

Tim.




Yes. Sell your house and move closer to the 1260 station.


While I'm about a mile from WMAL's towers, I believe that I'm within
about 5 miles of WWRC 1260's towers, and they both are listed by the
FCC as running 5kW. So at least it wouldn't be a very far move :-).

WWRC's signal is pretty damn lousy for a 5kW transmitter just a couple
of miles away. I mean, it doesn't help that WMAL's harmonic is stamping
all over it in my neighborhood, but even when I get away from my
neighborhood reception is pretty bad even within a 10 mile radius.

Tim.