Tracking down power line noise
 

A good O-scope can be many kilobucks. Mine was, Tektronix, but worth it.


Sometimes fate smiles on us. A friend, K9PGN SK, of my Dad's, W9EHS
SK, found two "in a dumpster" when some place was closing down. Gave
one to Dad.

100 MHz. HP Dual trace storage. works 100%

73, K9DCI via the arrl reflector CallSIgn atsymbol ARRL period NET

Tracking down power line noise
 

On Jul 12, 3:23*pm, Noskosteve wrote:
A good O-scope can be many kilobucks. Mine was, Tektronix, but worth it..

Sometimes fate smiles on us. *A friend, K9PGN SK, of my Dad's, W9EHS
SK, found two "in a dumpster" when some place was closing down. * Gave
one to Dad.

100 MHz. HP Dual trace storage. *works 100%

73, K9DCI *via the arrl reflector *CallSIgn atsymbol *ARRL period NET

Yeah, I picked up an HP 54645A like that. I hauled some trash off to
the dump and there it was in the recycling area so I recycled it. It
even had a recent cal sticker.

Jimmie

Tracking down power line noise
 

JIMMIE wrote:
On Jul 12, 3:23 pm, Noskosteve wrote:
A good O-scope can be many kilobucks. Mine was, Tektronix, but worth it.
Sometimes fate smiles on us. A friend, K9PGN SK, of my Dad's, W9EHS
SK, found two "in a dumpster" when some place was closing down. Gave
one to Dad.

100 MHz. HP Dual trace storage. works 100%

73, K9DCI via the arrl reflector CallSIgn atsymbol ARRL period NET

Yeah, I picked up an HP 54645A like that. I hauled some trash off to
the dump and there it was in the recycling area so I recycled it. It
even had a recent cal sticker.

Jimmie

Now if only someone would give me an old 547 with a spectrum analyzer
plug-in.
Bill

Tracking down power line noise
 

Noskosteve wrote:
...I used a ... shirt pocket AM receiver to find the offending transformer.


Thansformers themselves VERY, VERY, VERY rarely make noise.
Insulators, connections and other connecting hardware are the cause.

Mchenry / McCollum Lake

Poles.

I'm actually in Wonder Lake. It's a Wonder it's still a Lake because
no one wants to have it dredged (but they surely want the "lake").

73, Steve, K9DCI atarrl point net

Sad to hear that. I used to swim in it and in 1954 I could watch the
steam engines hauling the daytime commuters to Chicago on the far side
of the lake.
Times change.
Bill Baka

Tracking down power line noise
 

On Jul 13, 5:44*am, Bill wrote:
... I used to swim in it and in 1954 I could watch the
steam engines hauling the daytime commuters to Chicago on the far side
of the lake.
Times change.
Bill Baka

Hmmm. Wonder where that rail line could have been. None near Wonder
lake now.
Perhaps it was McCullom Lake you mentioned - there *is* a rail line
near it.

73, Steve, K9DCI

Tracking down power line noise
 

Noskosteve wrote:
On Jul 13, 5:44 am, Bill wrote:
... I used to swim in it and in 1954 I could watch the
steam engines hauling the daytime commuters to Chicago on the far side
of the lake.
Times change.
Bill Baka

Hmmm. Wonder where that rail line could have been. None near Wonder
lake now.
Perhaps it was McCullom Lake you mentioned - there *is* a rail line
near it.

73, Steve, K9DCI

It was McCullom lake, about 8 houses to the right of mine down the road.
My grandparents lived about 6 houses to the left, so it was ideal for
me as a young child. I once hiked through the corn fields (now condo
fields) to downtown McHenry and was about 100 feet from a steamer
spinning those huge wheels on startup. That was something I will never
forget, just the raw power and mechanical stuff up close.
That, to me, was American life. I also got into early morning television
DX'ing at about 5:00 A.M. turning the rabbit ears and seeing what I
could get. I got Grand Rapids, Mich once and Racine's test pattern once
and a few more buried in the snow. At any rate I was hooked on radio and
television stuff.

Bill Baka

Tracking down power line noise
 

I once had them track down noise when I lived in North Texas, and the source
was insulators with loose hardware about 2 miles away, destroying 40 and 80
for me. Yup, it is all hooked to a huge antenna...

-GeorgeC

W2DB


"Rick" wrote in message
...
I have been wrestling with power line noise here for almost a year.
Power company hasn't been very successful in locating it so I started a
coordinated search
on my own. Thinking if I can tell them for certain which poles have the
problem they can confirm and maybe fix.

The noise is a deafening 20 over 9 on 80 meters which makes DXing on 80
and 160 impossible.
The noise can be heard at my QTH as high as 10 and 6 meters but it isn't
troublesome on those bands because it can only be heard at about an S7
level when the yagi is pointed at 210 degrees.
I thought maybe my means of analysis might be interesting to discuss and
maybe others would have other suggestions.

There are 7000 volt lines running on a highway past my house. Tracking
the source on 80m seems impossible.
I made a 2 ft square loop antenna, which has some directivity but the
noise level using it seems to not change
much as I travel the highway. On 10 meters, using a 4 ft whip on the car,
the noise is also hard to localize but
seems to increase in the vicinity of 1 mile from home. 6 meters using a
whip is similar. I found that if I'm close
enough that the 6 meter signal is around S7 I can switch to 2 meters and
again peak the noise by driving slowly up and down the road.

So using this technique and driving 2 miles in each direction I have
managed to find 2 spots, one on the highway and one on a cross road, each
about 1.2 miles from the QTH. I then built a 432 MHz 8 element quagi beam
which enabled me to pinpoint the offending pole at these two locations.
(I have put a LOT of effort into this project !)

At this time I am waiting (hoping) for a return call from the power
company to verify my dicovery.

So my question for the group - Can either of these locations 1.2 miles
distant cause such horrendous noise levels on 80 meters? Is it possible
that a weaker noise source much closer to me is the culprit or are all of
the power line malfunctions detectable on 440 MHz?

Rick K2XT

Tracking down power line noise
 

In article , "George Csahanin"
wrote:

I once had them track down noise when I lived in North Texas, and the source
was insulators with loose hardware about 2 miles away, destroying 40 and 80
for me. Yup, it is all hooked to a huge antenna...

-GeorgeC

W2DB


Hello, and years ago I needed to do some electrically-small antenna tests
at one of our NRL field sites. These tests involved the entire 2-30 MHz
band so it was always a challenge to find a quiet spot (We were using
rack-mounted R-390 receivers in the testbed). In addition to the usual
atmospheric noise and radio station interference there was always what
appeared to be some local electrical noise that came and went and was
worse on some days than others. A.C power to the site was brought in via
utility poles to pad-mounted step-down transformers.

One of my cowarkers suggested a technique for locating interference that
he claimed to have success with in the past: A hand-held sledge hammer is
used to whack the utility pole while listening for an associated change in
noise on a cheap MW band transistor radio tuned off-station. My cowarker
claimed that if a cracked insulator(s) was the perpetrator this technique
would confirm it.

We tried this technique at the site but with no success. We also drove
down the site access road about 1/4 mile with a car AM radio tuned
off-station and also got the interference in the vicinity of the utility
poles. As a result we never did locate the source. My conclusion was
that while the interference was being coupled to the antenna-under-test it
may have been generated at a considerable distance from the test site and
conducted via the overhead power lines. Sincerely, and 73s from N4GGO,

John Wood (Code 5550) e-mail:
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

Tracking down power line noise
 

Hello, and years ago I needed to do some electrically-small antenna
tests at one of our NRL field sites. These tests involved the entire
2-30 MHz band so it was always a challenge to find a quiet spot (We
were using rack-mounted R-390 receivers in the testbed). In addition
to the usual atmospheric noise and radio station interference there
was always what appeared to be some local electrical noise that came
and went and was worse on some days than others. A.C power to the
site was brought in via utility poles to pad-mounted step-down
transformers.

One of my cowarkers suggested a technique for locating interference
that he claimed to have success with in the past: A hand-held sledge
hammer is used to whack the utility pole while listening for an
associated change in noise on a cheap MW band transistor radio tuned
off-station. My cowarker claimed that if a cracked insulator(s) was
the perpetrator this technique would confirm it.

We tried this technique at the site but with no success. We also drove
down the site access road about 1/4 mile with a car AM radio tuned
off-station and also got the interference in the vicinity of the
utility poles. As a result we never did locate the source. My
conclusion was that while the interference was being coupled to the
antenna-under-test it may have been generated at a considerable
distance from the test site and conducted via the overhead power
lines. Sincerely, and 73s from N4GGO,


Just in the past few months or more there was a nice article and
product written in either CQ or QST magazine. I have just gone through
the Index for every issue for the past 4 or 5 months of both magazines
and can not find that article.... very frustrating.

The article outlined a product ( kit?) for an untrasound receiver and
illustrated how the author configured it in order to find power line
interference from just the sources you are looking for. It is a much
more elegant solution than trying to use radio and usually pinpoints the
problem right down to the proper cross-arm on a pole.

Wish I could provide more info but I've spent the last half hour
looking for this and am apparently over-looking it. ... sigh

good luck


Ed K7AAT




..

Tracking down power line noise
 

While not the article I was just referring to in my just previously
posted comment, there is a good how-to build project in the April 2006 QST
on this.

Ed K7AAT




..