Topband: Bye bye Birdy!

[Tom Rauch]

> Well, I assumed it was an AM broadcast birdy on 1825, but Hardy N7RT
> assured me that was not possible.  He said that intermod products would
> only occur on even multiples of 10 Khz.  Sure enough, after checking all
> the computer monitors in the house as he suggested, I found the 
culprit!

True enough about AM stations, and I'm glad you found your 
problem, but keep in mind SW BC stations can and do have IMD 
on the "fives". 

A north Georgia station had two transmitters running (one on SSB) 
and the IMD product came out on 1.805 MHz (they repaired it 
within two days of being notified). The owner was an amateur, and 
a nice fellow.

WWCR had one on 1.855 and other frequencies. They took a long 
time to correct their problem, but it appears to be gone.

SW BC stations can be a problem, because they run multiple multi-
KW transmitters through mostly low pass filters into large arrays 
that radiate well on 160 meters.
73, Tom W8JI
w8ji@contesting.com



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