On 2012-09-15, at 8:03 AM, Pete Smith N4ZR wrote:
> This may be in the category of "you should never say never, when it comes to
> RFI". Back in the 80s, when I lived in a townhouse, I was focusing on 80
> meters to finish 5BDXCC. I became aware of local RFI covering two segments of
> about 10 KHZ at (wouldn't you know?) 3500-3510 and 3790-3800. It was there
> some of the time, and not others, tending to come on in the morning just
> before dawn.
>
> I walked the neighborhood with a portable radio, and localized the racket to
> a neighbor's townhouse. Though I barely knew him, this very nice guy invited
> me in to try to find the source. We looked at instant-on TV sets and other,
> similar sources, to no avail. Then, just as I was leaving in defeat, he
> switched off a bathroom light fixture (ordinary 110v bulbs, spst switch).
> The noise started. Switch on, noise off. Too weird. He confirmed that he
> was in the habit of leaving the bathroom light on at night and turning it off
> before leaving for work.
>
> Carrying niceness further, he allowed me to replace the light switch, and
> though we didn't expect much, that cured the noise! Both the original switch
> and the replacement were ordinary 72-cent "silent" types from the local big
> box store.
>
Back about 23 years ago, when we still lived in the 'burbs, a neighbour three
houses away from me complained that I got into her telephone. This only
occurred on those times when I operated 10-meters, which was a LOT at the time,
too, on account of favourable conditions back then...
Well, I wrote to the phone company, & they replaced her units with upgraded
"...new and improved" ones---yet the RFI persisted, sporadically. So I enlisted
help from a coupla Hams at the local club: they descended upon my place, & the
testing began in earnest. My buddies could hear no RFI whilst I stayed in my
shack & put a signal on the 28-MHz band---yet she insisted she could still copy
my signal through her handset! So I walked over to the house, and myself took
the handset & listened, while the guys at my place went on the air. I was
SEATED at my neighbour's couch, the phone beside me---and I heard nothing. I
passed the handset to my neighbour who was STANDING nearby---and she claimed it
was still there! I could not believe her, and in frustration I arose off the
couch, put the handset to my ear---and lo & behold, I could hear the
interference as well!
Incredibly, the coiled handset cord while I was seated was immune to RFI---but
as soon as it was outstretched, it must have acted like a resonant loaded
vertical on 10-meters!
No amount of handset bypassing / filtering ever eliminated the RFI in the
cord's uncoiled state...but happily we moved out to the country shortly
thereafter, & that sad episode in my Ham career was at long last behind me...
~73~ de Eddy VE3CUI - VE3XZ
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