[Lowfer] Re: Progress comes to the boondocks (finale, I hope)

Thu, 21 Nov 2002 17:54:21 -0600

Did you get to see what value the filter cap was that they installed??? I
would like to try a couple of caps to ground from each side of the 240v line
here. I have some new noise lately that wipes out most of the LF signals and
is a headache on 160-meters.
Thanks,
Mike>WE0H
http://www.we0h.us/lf.html

-----Original Message-----
From: [email protected] [mailto:[email protected]]On
Behalf Of Lyle Koehler
Sent: Thursday, November 21, 2002 4:10 PM
To: lowfer reflector
Subject: [Lowfer] Re: Progress comes to the boondocks (finale, I hope)

Two men from the power company showed up today to install their "standard"
filter, which is just a capacitor with a couple of clips to attach it across
the 240 volt line (better them than me). I stood by with my el cheapo
longwave receiver to see if it made any difference. In the immediate
vicinity of the meter, the noise was just as bad with and without the
filter. The guys even removed the filter and the meter, and turned the power
back on to make sure that all the noise was coming from my meter. On my
relatively insensitive receiver, I could hear almost no noise with the meter
removed, even with the radio within a couple of inches of the power lines.
An obvious solution was to leave the meter out, because it obviously wasn't
necessary, but the guys didn't think that was an option. So they put the
meter and the filter back in. Then I went to the point where the wiring
enters my house (the meter and transformer are about 100 feet away). Hey, no
noise! On my main receiver in the shack RM and BRO were nice and quiet on my
old standby balanced loop. Without the filter they were not audible unless I
turned on the receiver's noise blanker. DIW was also solid copy in mid
afternoon. Looks like I'm back in the receiving business!

In the meantime, we had a couple of fairly nice days (temperatures in the
upper 30s, so I tried to fix the problem myself by installing an isolated
single-turn loop about 150 feet from the house. My plan was to use an X
frame with 15 foot diagonals, and to suspend the loop in a tree a la Mitch
Powell's loop. The first attempt was with some very flimsy 1/2 inch PVC pipe
(the hardware store in town didn't have what I wanted). It didn't survive
dragging it over the rail fence into the pasture. Then I got a brilliant
idea that the loop didn't need an X frame if it is suspended in diamond
configuration; all it takes is a spreader in the middle. I had some aluminum
tubing and fiberglass rod that made an adequate spreader. It bows a little,
but that helps to maintain a bit of tension in the loop.

So now I have this great 10-foot square series-tuned (at about 186 kHz) loop
of #10 wire with a matching/isolation transformer, well away from the power
wiring. Dumb thing picks up just about as much noise as my old faithful
balanced loop 70 feet from the house. I went outside last night and put
another isolation transformer in the woodshed, where there was a splice
between an existing coax run and the new run out to the loop. At first it
didn't work at all because there was a short in a connector. Finally got
that fixed, but there was no apparent change in the noise pickup. Not enough
to detect by ear, anyway.

I was going to look for a quieter spot to hang the loop, but now that may
not be necessary. The new loop should provide some benefit in rejecting
noise from the computers in the shack; I will take some measurements to find
out. And although the loop isn't quite as simple as Bill A's tree antenna,
I'll try to write up a description and post it on the Web.

Lyle, K0LR

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