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

Rick wrote:
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?

There was an article in QST (or was it CQ?) about building a ultrasonic
"downconverter" to listen for noise sources. Yup, sound.. Many (most?)
Power pole RFI sources are mechanical in nature, and have an ultrasonic
component.

re the Power company. They might be more cooperative if they knew that
you could involve the F.C.C. Especially if you decided to "help" them by
finding many more sources of noise.

On Thu, 09 Jul 2009 13:54:10 -0400, Michael Coslo
wrote:

There was an article in QST (or was it CQ?) about building a ultrasonic
"downconverter" to listen for noise sources. Yup, sound.. Many (most?)
Power pole RFI sources are mechanical in nature, and have an ultrasonic
component.

It would seem easier to build a multipole high pass filter (above 200
Hz, say) and feed a many turned loop into it, measure the AC out of
the filter.

73's
Richard Clark, KB7QHC

There was an article in QST (or was it CQ?) about building a ultrasonic
"downconverter" to listen for noise sources. Yup, sound.. *Many (most?)
Power pole RFI sources are mechanical in nature, and have an ultrasonic
component.

re the Power company. They might be more cooperative if they knew that
you could involve the F.C.C. Especially if you decided to "help" them by
finding many more sources of noise.

Yup. Current (July) issue of QST. A kit that looks very interesting.

Paul, KD7HB

"Rick" wrote in
:

....
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.

If you study the pattern of a small loop antenna, it has a pair of deep
nulls. These are the most useful for locating the direction of the
source.

The nulls will not be as deep, and not ideally located if the feedline is
also part of the antenna, ie if the loop is not well balanced. So much so
that common mode current effects may render the antenna fairly useless
from a directivity point of view.

You did not mention the measures you took to assure loop balance /
insignificant common mode current.

Realise also that you may be trying to locate the cause of the emission,
but the loop (properly constructed and used) leads you to the radiation
source, and the power lines are very large and very effective antennas.
Nevertheless, it should be relatively easy to locate the cause of the
emission.

From a practical point of view, I have used a small loop and portable
receiver for locating and measuring emissions from BPL over HF, and noise
due to fautly transformer bushings, cracked insulators etc. Worked a
treat for me. One loop is described at
http://www.vk1od.net/antenna/SmallUn...Loop/index.htm .

Owen

"Owen Duffy" wrote
...

If you study the pattern of a small loop antenna, it has a pair of deep
nulls. These are the most useful for locating the direction of the
source.

A possible explanation for why the 80 meter noise couldn't be nulled is that
at most I
was 100 yards from the line and the noise was radiating from all along the
line. That's what it
seemed to be. On the broadcast band, the loop was easily able to locate the
direction of
the NYC radio stations from here in central NJ so I think the antenna was
doing it's job..


You did not mention the measures you took to assure loop balance /
insignificant common mode current.

My loop was a square made out of ribbon cable. 1 foot on a side, 7 turns.
The ends of the multiturn loop were attached to a broadcast variable cap.
One turn of the same ribbon cable was the coupling loop, which I connected
to a 6 ft length of RG58 with a BNC connector. The cap peaked the signal or
noise up
nicely.

Realize also that you may be trying to locate the cause of the emission,
but the loop (properly constructed and used) leads you to the radiation
source, and the power lines are very large and very effective antennas.

Understand, that's the conclusion I came to and the reason I switched to
10m-70 cm to
home in on it.


From a practical point of view, I have used a small loop and portable
receiver
The photo on that web site is essentially what I built, except mine was
multiturn, and had no balun.
I was listening at 2 MHz.

Rick

"Rick" wrote in
:

....
The photo on that web site is essentially what I built, except mine
was multiturn, and had no balun.

What you described is not IMHO a substitute for an effective balun, so
you can expect shallower nulls, and a distorted pattern (ie unequal nulls
and the nulls not orthogonal to the plane of the loop.

Although the power lines act as a very long antenna, I have had no
difficulty locating BPL injection points using the loop nulls. If you
stand under the power lines, you won't get a result, you need to move
away from them, preferably at least a quarter wave, and not near other
conductors (eg metal rainwater plumbing, other overhead metallic
services, metal fences, motor vehicles, buildings with sarked walls etc).
That is a big ask, but if you do that, and use the nulls, you should
readily get a good set (ie reliable, convenrgent) of cross bearings.

Sure you can look for interference at 70cm or at ultrasonic
frequencies... but that won't work unless the source is truly wideband.
The other thing is that if you make a complaint, demonstrate emissions at
70cm, and they fix them at 70cm, what do you do if they didn't solve your
primary problem. I have seen people do that, and the power company at
significant expense solved the reported problem, but not he complainants
real problem. Further complaints were treated as vexatious... 'quick as
we fix one problem, you find another'.

IMHO, better to measure the problem at the primary frequency, report the
real problem, not the cause, but the primary impact on yourself.
Depending on the jurisdiction, power companies may not be obligated to
eliminate the emission, merely to reduce it to comply with some standard,
and in that case, absolute measures of field strength may become
relevant.

Don't dismiss the loop and receiver, highly likely that if the regulator
attend to establish whether there is a case or not, they will *measure*
the emission field strength with a calibrated loop and receiver.

Owen

"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.


My local utility has one tech who does power line noise investigations and
I'm happy that he solved my problem. He identified three "problem poles"
and a week later, the noise was gone.

I can't answer your question about how far power line noise will travel but,
since you've put so much effort into this already, this next may be worth
doing, too.

One of the tech's tools was an audio detector, which he aimed toward the
tops of all the poles on my block. It was a 16-inch clear parabolic
reflector with a microphone mounted at the focal point and an amplifier
feeding headphones and a meter. The tech was listening for the sound of the
offending arc. Never mind the RF -- find the faint sizzling noise by ear!!

For a small fortune, these guys will sell you one: http://www.paradish.com/

You could definitely make one. This article
http://www.solorb.com/elect/misc/bige/ illustrates the idea (from a Google
search of "big ear" microphone) and it looks like he used an old wok.
(Are woks parabolic.)

So, if you want to impress the power company ...

Sal

"Michael Coslo" wrote in message
...
Rick wrote:
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?

There was an article in QST (or was it CQ?) about building a ultrasonic
"downconverter" to listen for noise sources. Yup, sound.. Many (most?)
Power pole RFI sources are mechanical in nature, and have an ultrasonic
component.

re the Power company. They might be more cooperative if they knew that you
could involve the F.C.C. Especially if you decided to "help" them by
finding many more sources of noise.

Agree with last posting regarding an ultrasonic receiver, that is most
likely what the power company was using. Other equipment for locating
powerline noise is a VHF AM receiver and foxhunting type yagi, the signal
will be much weaker at VHF which should make the source more obvious when
found.
A common feature of powerline noise is that it is intermittent and may
disappear for days and vary in intensity from one hour or day too the next.
Power line noise is often the result of loose hardware and dirty insulators
with the noise being generated by small spark gaps between fittings.
Therefore a bit of rain the dry gaps become conductive of the leakage
current and the noise disappears. I mention this because if the noise is
continuous and un-varying it may not be generated by the powerline
equipment, but may be generated from another source and simply travelling
and radiating from the powerline. R.F. welding for example.
Power companies or the F.C.C. may have an information brochures for TVI
complaints which may show examples of various source types as they appear on
TV screens, this may assist in identifying the interferance source.
That shows my age, 'brochures' check their website! And this will not work
for digital TV.

If the F.C.C. is anything like Australian authorities TVI will carry more
weight than ham radio, therefore if you also have an accompanying TVI
problem report that for prompt action.

Best of luck

Peter VK6YSF

http://members.optushome.com.au/vk6ysf/vk6ysf/main.htm

Owen,
You bring up some very interesting points, precisely what I was asking for
in my original post.
Thank you very much for your assistance.
My theory right now is this:

I have found 2 noisy poles using 440 MHz, both 1.2 miles from me. I HOPED
that they would solve my 80 meter problem, once repaired.
As I go lower in frequency, down to 10 meters using vertical whips, I
confirm that the noise can be heard farther away, as much as about 1/2 mile
on 10 meters.
I am assuming that the 2 MHz component of the broadband noise is being
conducted on the lines with very little attenuation for the 1.2 miles to my
house where it is 20 over 9 on a Beverage parallel to the lines.
Using my loop at 2 MHz I am essentially unable to get any bearing because
the source is essentially a couple miles in length. ???????? And I can't
get any significant distance away from the power lines. (One place on my
property is 200 yards from the lines but the loop can't determine a null.
Yet it does fine with locating BCB stations, so I think it should be usable
if the noise was a point source).

Although the power lines act as a very long antenna, I have had no
difficulty locating BPL injection points using the loop nulls.
What frequency do you look at for BPL? upper HF (10-20 MHz, where it looks
more like a point source?)


If you stand under the power lines, you won't get a result, you need to
move
away from them, you should readily get a good set (ie reliable,
convenrgent) of cross bearings.

I am failing at that so far, see above.


Sure you can look for interference at 70cm or at ultrasonic
frequencies... but that won't work unless the source is truly wideband.

This statement puzzles me. Can you please explain more? Can it be that the
poles which clearly
show lots of noise at 440 are NOT the ones causing my problem at 80 meters?
i.e. can there be defects which generate noise peaking at LF and not
detectable on 440?

The other thing is that if you make a complaint, demonstrate emissions at
70cm, and they fix them at 70cm, what do you do if they didn't solve your
primary problem.

That would be my worst nightmare. That's why I am looking for a better
understanding as I asked above.


IMHO, better to measure the problem at the primary frequency, report the
real problem, not the cause, but the primary impact on yourself.

I did that, starting 11 months ago. I played dumb, just said here's my
problem.
The power company guy who has been trying to help me has a wideband spectrum
analyzer, and uses a 300 MHz-1GHz LP antenna, hand held. For low
frequencies just a pull-out whip. He prefers to use his hand held
ultrasonic device with headphones, probably because he has had good success
with it. He let me experience it once and it definitely can hear a problem
on a pole. So I'd say right now he has the best capabilities at ultrasonic,
and I do at UHF (with my 8 element Quagi and sensitive receiver), and
neither of us does at low HF.

Rick