TopBand: Topband BC Stn. Birdies

[David Kennedy]

I have read, with considerable interest, most of the theories
about how the gaggle of BC station sigs are generated and 
heard EVERY 10 Khz across the 160 meter band. I think there 
is no doubt these sigs are mixing products (910 + 820 = 1830,
etc.) but I tend to reject the idea that these sigs are somehow
generated by diode detection due to corrosion in tower joints,
down spouts, power lines, Beverage antennas or some other
mysterious outside source in the neighborhood.

I feel that one of the top banders might be close to the right
answer when he suggested that the culprit diodes might be in
our receiver front end band filters. In discussing this subject
with Rip, W4FX, I suggested this theory was N.G.because my
external receiver preamp amplified these birdies along with
everything else, QRN, etc. Rip replied "How about the 
3-element diode (transistor) in your preamp?"

So far I have not been able rebut this explanation. The birdy
signal strength varies greatly as I switch from one Beverage 
antenna to another. With 7 2-wire Beverage antennas I have 14 
directions available. The birdies peak at random in many 
different directions. Isn't it possible that our state of the art
receiver front ends are acting like broadband crystal sets acted
60 years ago when we were thrilled at hearing the local BC station
with no batteries? Can anyone think of a fault in this theory?

Merry Christmas. 73, Dave--N4SU

 

--
FAQ on WWW:               http://www.contesting.com/topband.html
Submissions:              topband@contesting.com
Administrative requests:  topband-REQUEST@contesting.com
Sponsored by Akorn Access, Inc & KM9P