"Mark S. Holden" wrote:

bpnjensen wrote:

Thanks to Dave, Mark and Telemon - all very interesting and useful
suggestions. Once I get the wires up, I will try some of these
configurations. I have never had any problem that I could trace back
to, say, my PC or my TV, but maybe the beads will help clarify whether
these are problems.

Telemon, when I differentiated between beads and cores, I guess I
meant to differentiate between mounting styles - I think of beads as
"slipped over" the cord, while I think of "cores" as being
doughnut-shaped toroids through which the cords are "wound" several
turns.

It sounds like the beads or toroids would function better than the
rods for most RFI suppression purposes. Per Mark and Dave, it also
sounds like the more beads used, the better isolation one can achieve.

From what I gather, in addition to the specific points that each of
you made, the AC mains and RFI noise that the ferrites will help to
overcome is usually very local in nature, typically generated at one's
own house or *maybe* with one's immediate neighbor. It sounds like
they might be less effective on RFI picked up directly by the antenna
from, say, a scratchy high-voltage power line 150 yards away, or a bad
streetlight down the block, or the like.

Oh, to live back in rural Massachusetts again...I remember quiet
airwaves...

Thanks!
Bruce

Noise from an arcing power line transformer can be nasty as it's a broadband transmitter with plenty of power connected to lots of wire.

Took me months to get them to replace the transformer across the street from my house. In round numbers, it was 150 feet from the closest antenna, and still made that antenna useless. The antenna that was a little over 400 feet away from it still picked
up some noise.

I do think putting your antenna as far as possible from noise sources is the best way to go. Running your coax underground is also helpful.

But mostly, you just need to look at what you have to work with on your property, and figure out how to make the most of it.

I've had a problem here since June, but the local BPW is working on it, but can't quite seem to locate the problem.

After a conversation with the Director of Electrical Services here yesterday it would seem as though they are bringing in some outside help.

They've tried here with some sophisticated sniffing equipment, both RF and ultrasonic.

My good fortune here has been that the Director is a Extra Class amateur and understands what the problem is causing.

We successfully fixed a problem similar to the one I'm currently experiencing last Fall in about 3 weeks. It involved replacing several thousand dollars of worth of equipment, and I'd suspect that this problem will require the same.

If they don't fix it soon, I suspect they'll be paying for a few trips up to the northern dx'ing site, and they've been informed of this!

dxAce
Michigan

http://www.iserv.net/~n8kdv/dxpage.htm