Tracking down power line noise
 

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
 

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.

Tracking down power line 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

Tracking down power line noise
 

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

Tracking down power line noise
 

"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

Tracking down power line noise
 

"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

Tracking down power line noise
 

"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

Tracking down power line noise
 

"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

Tracking down power line noise
 

"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

Tracking down power line noise
 

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

Tracking down power line noise
 

Sal M. Onella wrote:
"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!!

You got it.

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.)

The old style cheap woks are parabolic. The newer ones which have a flat
bottom are not. I have a 24 inch Al parabolic dish. It isn't very
stealthy, but it's lighter and bigger than the woks.

There are some nice features about hunting down RFI problems with sound.
That parabolic reflector can be aimed right at the pole, and in
combination with the short wavelength esp at ultrasonic frequencies will
let you zoom in on the problem pretty quickly. Trying to close up DF
with HF is like trying to change directions on a cruise ship.

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

If you are doing it near your own house, DO check in with the neighbors
telling them that you are locating the source of noise, and it might
eliminate any interference they might be getting now.

- 73 de Mike N3LI -

Tracking down power line noise
 

Rick wrote:
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?

Absolutely. The closest analogy I can think of is RFI in a vehicle. I
had rfi sources in my vehicle that were bad on 80, and not heard on
other bands, and vice versa. Some sources are broadband, some are not.


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.

1. Locate what you think is the problem via the method of your choice
(though I would suggest multiple verifications. I thiink that is the key
to isolation of your noise source.

2. Determine that the problem is also on 80 meters. You might use a
radio with a poor antenna. Work your wy towards and away from the
suspected source.

3. Realize that if you go looking for RFI sources, you will find more
than one. Likely you'll find many.

If you have 30 over 9 RFI on 80 meters, I would not suspect the source
to be very far away. I'd expect it to be much closer. It might even be a
non-power line source, if you can't locate it on the lines.

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.

I don't doubt it, If I fire up my Spectrum analyzer at home, there's a
cacophony of signals to look at. The best way to find RFI is if there
are harmonics of the signal.


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.

And there is a clue in that, Rick - I think. There is a possibility that
the noise is local. Does anyone have a fence charger, golf cart battery
charger, treadmill, CO2 detector, even possibly a wall wart that might
be making strong local noises? Can you run your rig on 12 volts and turn
off the power at the breaker box? Can you get the neighbors to do the same?

note: saying that you heard the electrical noise, and a little chat
about how if there is electrical noise coming from their house, and it
*might* just pose fire danger might just convince them to help.

If the power goes off, and so does the noise, you've traced it down to a
lot smaller area.

You may have tried this already, but those levels are just so high that
I have to wonder.

- 73 de Mike N3LI -

Tracking down power line noise
 

On Fri, 10 Jul 2009 14:33:57 -0400, Michael Coslo
wrote:

Some sources are broadband, some are not.

It is quite often related to the pulse width and the pulse shape
coming from the source. Some shapes offer odd harmonics 3-5-7-9, some
even 2-4-6-8 (primary products, that is, as they all offer a full
complement of odd and even).

73's
Richard Clark, KB7QHC

Tracking down power line noise
 

"Rick" wrote in
:

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 not surprised. The directivity of the 'antenna' varies with
frequency, as may be the power radiated.

Trial BPL emissions that I measured could be heard above the noise on 40m
in a mobile station more than 1km from the trial area. Remember that this
was an emission that its promoters (including the FCC) asserted would not
cause interference.

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.

That antenna configuration maximises coupling to the currents flowing on
the power 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).

But you are not limited to taking bearings from on your own property.

I will say again, if you are close to the power lines, eg within say, a
quarter wave, the loop mutual coupling with the power lines will reduce
its effectiveness for obtaining a valid bearing.


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 can say that again!


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?

It is not just a matter of whether a fault (eg a leaking bushing) creates
emission of constant power density from DC to daylight, the lines,
earthing system etc all introduce frequency effects on amplitude. You
could easily discover a relatively noise fault on 440 that is not the
root cause of high 1.8MHz emissions at your location.

My advice is that if you sense emissions at some secondary frequency,
always relate it back to the primary problem. It is OK if the power
company wants to locate faulty insulators with an ultasonic detector, or
a UHF detector, but when they have 'repaired' the fault, the valid test
of whether *your* problem is fixed is measurement or observation at the
frequency at which you suffered interference.

It is just a matter of logic.

For example, if you report a problem on 1.8MHz, and the power company
attends. They report that they found 3 faulty insulators and 1 case of
loose hardware using their ultrasonic detector and sledge hammer and
fixed them. Your problem must now be solved.

No, your problem is only solved when the interference at 1.8MHz has gone
away, it doesn't matter how many other faults they found and fixed while
investigating, until they fix the one(s) that cause your problem, the
problem is resolved.


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

Ok, they are all techniques for finding faulty equipment... but if they
don't measure the emissions at your place before and after, they have not
proven that the faults found contributed to the interference problem.

Is that hard to grasp?

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.

Again, I earlier made the point that detectable noise is not necessarily
actionable. It would be unreasonable to require power line emissions to
be undetectable. In that environment, measurement of the emission level
either in absolute terms or relative to ambient noise (the degradation
caused, if you like) may be relevant to whether the case is actionable.

My experience with BPL particularly, and also with weak signal working is
that hams, by and large, don't have much interest in noise, and therefore
much knowledge of noise as it limits the communications channel.

An anecdote: A notable VHF weak signal operator reported "I am suffering
interference at S9 to 40 over S9 on 2m" led to my question given that he
has a high gain array with masthead preamp etc "what does S9 mean?". I
was told that his system was 'calibrated', he adjusts the transceiver
input attenuator so that the S meter reads zero on band noise.

In the jurisdiction, there is a standard that limits power line emission
field strength (specified in uV/m) from power lines, and if it could be
demonstrated that the emission exceeded that, there was no question, it
needed to be reduced, not eliminated, but reduced to comply with the
standard.

But, S9 mean't nothing in terms of the standard, it did not providing a
compelling case of non-compliance.

BTW, in this jurisdiction, if a leaky insulator also affects local
broadcast reception, a report along those lines is more likely to get
action.

Owen

Tracking down power line noise
 

On Fri, 10 Jul 2009 10:39:46 -0400, Michael Coslo wrote:


If you are doing it near your own house, DO check in with the neighbors
telling them that you are locating the source of noise, and it might
eliminate any interference they might be getting now.

- 73 de Mike N3LI -

I use a slightly different approach. I have a battery powered marine RDF
and all I have to do is align it and follow it to the offending pole, or
house. Poles I can usually get fixed if I convince them it is a fire
hazard. Houses tend to have people who could care less about your hobby
unless you use the fire hazard thing again.
Bill Baka

Tracking down power line noise
 

"Michael Coslo" wrote in message
...


snip

There are some nice features about hunting down RFI problems with sound.
That parabolic reflector can be aimed right at the pole, and in
combination with the short wavelength esp at ultrasonic frequencies will
let you zoom in on the problem pretty quickly.

Funny ... how our minds work -- or don't work. I wrestled with the idea of
ultrasonic, trying to make sense of snooping for weak, high-order harmonics,
vice audible sounds. Despite a quarter century of regular exposure to
satellite dishes, personal and professional, I overlooked the fact that
dishes are more directive at shorter wavelengths.

Doh!

Sal

Tracking down power line noise
 

This is a long thread and I hope I read enough and am not repeating.

I've been involved in a power line noise problems here in McHenry
Illinois for the last year and can make a few comments.

There are some very good references on the ARRL Web site. I've read
them, one of the books and consulted with Gene Preston, K5GP a pro and
one of the paper's authors. They should be top on your list of things
to read.

Main page:
http://www.arrl.org/tis/info/rfi-elec.html

This is good, but long:
http://www.arrl.org/tis/info/rfi-elec.html

A good summary:
http://www.ctdxcc.org/powerlines/

Some others:
http://www.arrl.org/tis/info/pdf/0112068.pdf
http://www.egpreston.com/RFItalk.ppt

There's lots more on-line, but these will make you an expert quickly.
(:-)...

Power line noise is almost always quite broadband. It won't just be
on one band. Therefore, it is best to hunt on the highest frequency
available that hears the noise. The noise travels further at lower
frequencies and pinpointing a source is more difficult. Three pros I
have talked to say this. The author of one of the books uses a
modified TV antenna to get up to 900 MHz and above. An Engineer at
the equipment manufacturer, Radar Engineers, says the same thing :
hhtp//:www.radarengineers.com

They make an ultrasonic ear, a 330 MHz beam/Rx, and a wide range
receiver/spec analyzer for power line noise hunting. The local power
co here (ComEd) uses all these.


In addition, at higher frequencies you can get more gain in a
relatively small size and a resulting narrower beamwidth to better ID
the pole. I happen to have the same Cushcraft beam Gene Preston uses
(shown in his paper below) and it works nicely to pinpoint a pole or
when further away, a region of radiation.

My measurements show the same thing. The noise is at a lower level at
higher frequencies, so some gain may be in order. I also use preamps
at times.

I have access to the very same ultrasonic and 330 MHz.equipment. I
also have a 2M beam, 450 beam, 700 beam and 1296 beam, spec analyzer,
yadda, yadda....

We're pretty heavy into this and getting impatient with ComEd.

The ultrasonic will ONLY hear arcing that is in the air OUTSIDE
things. Our arrester problem has NO ultrasonic signature (our problem
appears to be up to 100 arresters causing noise 15dB above the level
when the line is de-energized).
The ultrasonic dish can identify an individual insulator or arcing
component.
Hot clamps and ground wires, yes ground wires, can be a significant
source. Including the large staples that hold the ground wire to the
wooden pole !!

The comments about making sure *your* noise is fixed is right on as
well. Identifying the particular signature of the noise should also
be done. This is with an O-scope so you can see the time signature
(the wave shape) This can also help identify multiple sources.


We currently are waiting for the manufacturer to test 30 arresters
that were swapped out. These arresters are 100% tested for RF noise
and I'm worried that the test is bad.

FYI:
They also have a 22 blank cartridge in them. If the arrester fails
such that is conducts and heats up, the cartridge fires and blows the
snot out of the ground connection to free up the line.

Good luck
73, Steve, K9DCI at arrl dot net

Tracking down power line noise
 

On Sat, 11 Jul 2009 21:56:47 -0700, Noskosteve wrote:

This is a long thread and I hope I read enough and am not repeating.

I've been involved in a power line noise problems here in McHenry
Illinois for the last year and can make a few comments.

McHenry? I lived there from 1948 to 1955 in the McCollum lake area.
Corn fields everywhere. When I went back in 1993 the old neighborhood was
still there but the cornfields had turned into condo-fields.
I would have hoped the new construction would have put the new wiring
underground so you would not have a problem.
Are things still on poles?

There are some very good references on the ARRL Web site. I've read
them, one of the books and consulted with Gene Preston, K5GP a pro and
one of the paper's authors. They should be top on your list of things to
read.

Main page:
http://www.arrl.org/tis/info/rfi-elec.html

This is good, but long:
http://www.arrl.org/tis/info/rfi-elec.html

A good summary:
http://www.ctdxcc.org/powerlines/

Some others:
http://www.arrl.org/tis/info/pdf/0112068.pdf
http://www.egpreston.com/RFItalk.ppt

There's lots more on-line, but these will make you an expert quickly.
(:-)...

Power line noise is almost always quite broadband. It won't just be on
one band. Therefore, it is best to hunt on the highest frequency
available that hears the noise. The noise travels further at lower
frequencies and pinpointing a source is more difficult. Three pros I
have talked to say this. The author of one of the books uses a modified
TV antenna to get up to 900 MHz and above. An Engineer at the
equipment manufacturer, Radar Engineers, says the same thing :
hhtp//:www.radarengineers.com

They make an ultrasonic ear, a 330 MHz beam/Rx, and a wide range
receiver/spec analyzer for power line noise hunting. The local power co
here (ComEd) uses all these.


In addition, at higher frequencies you can get more gain in a relatively
small size and a resulting narrower beamwidth to better ID the pole. I
happen to have the same Cushcraft beam Gene Preston uses (shown in his
paper below) and it works nicely to pinpoint a pole or when further
away, a region of radiation.

My measurements show the same thing. The noise is at a lower level at
higher frequencies, so some gain may be in order. I also use preamps at
times.

I have access to the very same ultrasonic and 330 MHz.equipment. I also
have a 2M beam, 450 beam, 700 beam and 1296 beam, spec analyzer, yadda,
yadda....

We're pretty heavy into this and getting impatient with ComEd.

The ultrasonic will ONLY hear arcing that is in the air OUTSIDE things.
Our arrester problem has NO ultrasonic signature (our problem appears to
be up to 100 arresters causing noise 15dB above the level when the line
is de-energized).
The ultrasonic dish can identify an individual insulator or arcing
component.
Hot clamps and ground wires, yes ground wires, can be a significant
source. Including the large staples that hold the ground wire to the
wooden pole !!

Still poles?

The comments about making sure *your* noise is fixed is right on as
well. Identifying the particular signature of the noise should also
be done. This is with an O-scope so you can see the time signature (the
wave shape) This can also help identify multiple sources.

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


We currently are waiting for the manufacturer to test 30 arresters that
were swapped out. These arresters are 100% tested for RF noise and I'm
worried that the test is bad.

FYI:
They also have a 22 blank cartridge in them. If the arrester fails such
that is conducts and heats up, the cartridge fires and blows the snot
out of the ground connection to free up the line.

I can just imagine a really hot day.

Good luck
73, Steve, K9DCI at arrl dot net

Bill Baka
Real mail is
My parents transplanted me to California.

Tracking down power line noise
 

On Jul 9, 11:58*am, "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?

Rick *K2XT

Sounds about like a problem I had. I used an AM 60s vintange shirt
pocket AM receiver to find the offending transformer. When I called up
the power company I gave them the pole number and street address and
didnt tell them I was a ham radio operator. Instead I told them it was
interfering with me listening to my favorite talk show. They came out
the next day.

Jimmie

Tracking down power line noise
 

...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

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




..