Line Noise Follow-Up

Peter Hardie hardie at
Tue Aug 3 14:02:35 EDT 1993

On Tue, 3 Aug 1993, Steve Fraasch wrote:

> Last winter, I queried the field for help fixing a high tension power line 
> noise problem.  Thanks.  
> .....  I thought I would pass on my lessons from the school of hard knocks.
I didn't see your original query Steve. I'll add a few comments to your
lessons based upon 3 cases that I dealt with several years ago.  
> Here is an after-action report of lessons learned:
> - Use a 2 meter or other VHF receiver w/ am noise detector, 4 - 6 element 
>   yagi. 
Agreed. The use of VHF/UHF equipment with SSB/AM receive capability is
*ESSENTIAL* (I can't stress this enough :-). As you get closer, higher and
higher frequencies really help pinpoint the source.

A local ham was getting complaints from neighbours that he was interfering
with their radios etc. But at the same time he was getting S9++ buzz on
all bands to the point that he could only hear the strongest of stations.
3 or 4 of us converged on his place and took an initial beam heading from
his HF rig. It said north-west. So we all drove around NW of his place and
couldn't find anything. So we all went back to his place and I took my 2m
SSB rig into his house and hooked it up to his 2m beam. No doubt about it
- due SOUTH. So off we went and found a house one block south of him that
was radiating like crazy. We called in the DOC and they called in the
power company. The house was a duplex that had been converted into a 4-plex.
The two basement suites each had their own electrical panel. As soon as
they opened the door to one of the two suites they could hear the panel
was arcing. Fixed the panel and all was quiet. The kicker was that the
occupant of the suite was deaf! Could have been disastrous.
> - Troubleshoot in this order: insulators, disconnects, lighting arrestors, 
> line components.  
Mustn't forget all supporting hardware. Two of the problems I've had with
noise were caused by:
- a staple that was one of several intended to hold a ground wire to the
bottom of a support beam. It caused a phenomenal amount of noise from 6
blocks away and one whack with a rubber mallet (wielded by a power company
employee) fixed it.
- A bolt and nut that hold up the V-shaped support to which the main
wooden crossbar is attached (this crossbar then has the insulators and
power lines on top).
Over time the nut had worked itself loose and had fallen off. The chief of
the power company crew thanked me profusely for complaining! If that puppy
had given way there would have been on the order of 150kV hanging loose in
a residential back alley. During this visit they also fixed 3 cracked
insulators at different places along the line. I thanked them profusely
when they were done!

73 de Pete hardie at  VE5VA

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