I measured the noise
(actually, noted it) out to about 15 feet while walking around with a
portable radio.
This discussion about noise reminds me of the really nasty noise problems I
finally overcame. I needed clear reliable WWV reception for astronomical
observations (asteroid occultation timing). Tried more than a dozen
different antenna systems, including phased multi-elements. Each different
antenna system helped with only some aspect of the total noise problem and I
still couldn't satisfactorily eliminate the noise.
Strong -off frequency- interference, from multiple sources, was causing the
poor reception. I even tried different radios hoping for a better "front
end". No luck until I stumbled across the idea of putting resistors in the
loop. No doubt doing that "eats up" some of the desirable received signal,
but it also "knocks down" the interference to a lever that the receiver can
reject. Putting resistors opposite the feed point worked so well that I may
never build another antenna without using resistive loading.
If anyone is fighting a noise problem that seems to defy solution, they
might want to try incorporating carbon resistors into the design.
Doug Kniffen
