[RFI] Power line RFI situation
Rob Atkinson, K5UJ
Mon, 18 Mar 2002 19:13:29 +0000
I just recently started reading the mail on this list and it seems to be a
great resource. I'm sending this mail out to the list as a sort of status
report regarding my particular problem. I hope that as things progress I
can send updates and get advice with a few of you guys being familiar with
my situation. I live in an old neighborhood of St. Charles Illinois, a
suburb of Chicago. A river (the Fox river) flows through the middle of
town. My qth is about 100 feet from the east bank. High voltage power
lines on poles run along the east bank of the river. The city of St.
Charles owns and maintains the municipal power grid. They bill us for
electricity which they purchase from Commonwealth Edison. So the city is
responsible for fixing powerline problems.
After being qrt for about 18 years I set up a HF station late last summer.
I was dismayed to find a S7 level line noise, loud enough to make a lot of
qsos unworkable on 80, 40 and 20. It's not so bad on 15 and 10. For the
first several months I was preoccupied with solving some grounding, rf
feedback and antenna bugs. Lately I have gotten around to tackling the ac
noise problem which was next on my list after finally getting the shack set
up and the station problems fixed. I had taken a stab at it last fall to
the extent that I naively called the city electrical dept. to complain about
the noise. A young man called back a few hours later to tell me he drove
around my neighborhood & listened on his car radio for noise and didn't hear
anything. He suggested I make sure the noise wasn't coming from inside my
house. I told him okay, and realized this wasn't going to be so easy. I
had figured the noise was from outside because it went away when I
disconnected by antenna. I got a copy of the ARRL RFI Book and started
A couple of weeks ago I went around with a mw am receiver to DF the noise.
One way I know it's from outside my house is that I've observed that it goes
away when it snows or rains. The rest of the time it's there night and day.
The mw rx was too sensitive and nondirectional.
Over the weekend I found an old Alinco 2m/70 cm HT that receives air band on
AM. I found a battery pack for it that will
take a charge so I have been walking around with it using a loaded 5/8 w.
duck. I have it tuned to a bit above 108 Mhz and have also been driving
around with it connected to a 1/4 w. g.p. on the roof of my car. I've found
a couple of potential sources. I went to radio shack yesterday. They sell
a cheap 20 buck 6 el. yagi for the FM broadcast band. I bought one along
with a receive only balun and am going to use it to DF the problem with the
108 mhz AM rx. S7 noise is unacceptable. I could live with it if it were
maybe S1 to S3. But at S7 I can only work guys with beams and/or linears.
Anyone with 100 w. and a dipole is briefly workable but no fun and after a
few minutes I usually end the qso. I plan to drive around
St. Charles for several hours noting the possible sources (there's one real
bad one on the other side of the Fox river from me) then go back with the
yagi to try to isolate the pole(s). Then contact the city electrical dept.
& put everything on the table & see what they do.
What do you all think about this plan so far? Anyone else in this situation
where you are working with a municipality instead of a utility? Tnx 4 your
help & 73--GL with your own noise problems too.
St. Charles IL
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