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Old January 24th 07, 04:49 PM posted to rec.radio.amateur.antenna
R. Scott R. Scott is offline
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First recorded activity by RadioBanter: Jan 2007
Posts: 18
Default Local station bad harmonics on 80 meters


"Michael Black" wrote in message
...
"R. Scott" ) writes:
80 is basically useless. 3400 and 4000 I have a Pegged meter WFM signal
from 1380kc station here. I have mini harmonics ever 200kc that
basically makes 80meters unusable Its really annoying and the station
says they had their equipment recertified 2 months ago

This is hardly an antenna issue.


I know, but I thought it might be for them or me, so I came here (one of the
only groups I subscribe to)

You do realize that it may not be the transmitter?


Possibly, but You never know, it might have to do with their plans on moving
the antenna and upping power or the
recent storms we've had.

If your receiver (and you don't specify what it is) hasn't got
good strong signal-handling, the station may be overloading it
and causing the junk. And at first glance, it wouldn't be
obvious whether it's the receiver or the transmitter.


ICOM 706MKIIG ... Never had a problem in the 2 years Ive owned it, havnt
changed anything at my end.

Try a different receiver.


Ill see what I can find to use, good idea.


Borrow a spectrum analyzer, which should stand up well to strong
signals since it wouldn't be much use otherwise, and see what signals
are arriving at your antenna. If you do see signals that are traceable
to the broadcast station, then likely they do have a problem. But if
not, it's your receiver.


Ill see if I can find one

And it may not even be the receiver. There could be something acting
as a rectifier, that is picking up the transmiter signal and generating
harmonics for your receiver to pickup. A rusty rain gutter, or
a bad connection on an antenna, obviously something nearby.


only happend in the last month or two the Big clues that make me wonder is
if it was
a pure Birdie wouldnt it still be AM rather that Wide FM ? Makes me wonder
if the TX
is FMing some how.

You have no reason to doubt the station's word, especially since
they do have the rules to follow, and likely are in a worse
position than a ham with a bad signal. You are expecting the
transmitter to blame because you can't imagine your receiver
is at fault. But until you can actually rule out the latter,
you have no real reason to blame the transmitter.


I used to work at a Station and I know the rules they have to follow, I also
know that very shoddy
work is done at a lot and just signed off. Ill continue to check my end,
but If Ive never heard the
birdies before with the same station (Save the 706MKIIG and new coax on
occasion) Ive had for 18 years here
with no problems until the recent storms and the station has multiple
birdies and its in Wide FM rather than
AM ... makes me wonder.


Scotty W7PSK