[SFDXA] Noise Levels and Great Cobb EMC Response

[Norman Alexander]

This may be of interest for those chasing RFI from power lines.  The email below 
was forwarded to me from Leon K2EWB.  I have attached a build PDF for a ultra 
sonic noise detector featured in an April 2006 QST.  Hope this is helpful

Norm W4QN




 
All,

Just wanted to let you know how happy I am with the response that  I received 
from Cobb EMC regarding tracking down a S9+ noise source that was  hitting me on 
160m through 70cm. I sent Cobb EMC an email on a Saturday and  received a call 
on the following Tuesday, about 3 weeks ago. We met at my house  and let the 
crew foreman, Emory, listen to the noise I was hearing on all of the  bands. He 
agreed that there was a problem and told me he'd do his best to solve  it. 
Unfortunately, Emory had taken over his position about 4 months ago and by  his 
own admission hadn't worked too many of these issues during that four  months. I 
discovered that I was case number four and he was truly clueless as to  how to 
proceed other than driving around with his AM radio set between stations  
listing for static.

He identified what he believed was the pole with the  loudest noise level and 
proceeded to tighten all connections, bolts staples and  other bolt/nail on 
equipment and also replaced the lightning arrestors on that  pole. In the 
process of doing this my neighbors came out and asked what we were  doing and 
when I explained to them that we were trying to eliminate a static  source we 
started to hear about all of the problem that they'd been having on  their AM 
radios, cable TV, and telephone service. The more stories that they  told the 
more attentive the Cobb EMC representative became. After completing all  
maintenance on the first pole they left for another appointment with the promise  
to keep working on it. 


The two days later I received a call from Emory  who told me that they had cut 
off the power to my cul-de-sac for an hour with no  reduction in the static 
level. He said that while he had the power off they  serviced the poles on that 
line and where the line attached to the main supply  line. He asked if there was 
any difference to which I responded no. 


Driving to work during the following week I was talking with the normal  
drive-time bunch on the Kennehoochee repeater about the problems that I was  
having with tracking down the noise source when Mike Greenway, K4PI, jumped on  
the repeater and told me that he'd had good success using a homebrew ultrasonic  
parabolic dish. I asked if I could borrow it, he agreed, and the next day I was  
at his QTH borrowing the dish. After a brief training session I was on my way  
back home. Upon arriving at my QTH I pulled out the dish and started scanning on  
a pole in a direct line with the direction that my antenna indicated was the  
point of maximum strength. I scanned the entire pole and when I aimed at the  
lightning arrestor I heard a distinct low frequency buzzing/humming sound. I  
checked several other poles in the vicinity and could not detect any other poles  
with noisy equipment.

I called Emory with Cobb EMC and told him that I  thought I knew which pole and 
the device they should work on based on using an  ultrasonic listening device. 
He said that he would be happy to meet me on site  to see if the lightning 
arrestor that I had identified was the source of the  problem. He volunteered 
that he had been back out to my subdivision during the  previous week and were 
unsuccessful in trying to locate the problem during that  visit as well.

Today when I met him by the suspect pole I let him listen  to the detector and 
he agreed that it was emitting a sound. They used their  bucket truck to remove 
the arrestor and the second that they cut power to the  arrestor all noise 
ceased! They went ahead and replaced the arrestor and when  they power 
everything back up there was total quiet.

While wrapping up  Emory told me that they had a bunch of test equipment at 
their shop, including  an ultrasonic dish, but no one had told him how to 
operate any of it when he  took over his position. He asked me if I wouldn't 
mind some weekend having him  come to my house with the equipment and have me 
explain what it was supposed to  do and how to use it. I told him that I had no 
experience with any of that type  of equipment but he said that based on all of 
the help I'd given him track down  the problem he was sure that I could figure 
it out. I told him to give me a call  and we'd work out a time that worked for 
both of us.

In summary I  couldn't be more pleased with the level of support that I received 
from Cobb EMC  and specifically Emory Benson. The problem is solved, I made a 
friend, and I'll  get a chance to play with electronics that are way above my 
pay grade when he  calls me back. My biggest piece of advice is get involved; 
don't just call and  expect the problem to be solved. I ended up taking a total 
of 10 hours of  personal time to meet with Emory on two occasions but it was 
well worth it. One  thing that he said that made me smile was that the last 
problem that he'd worked  on was for a ham on US92 near I-575 behind the Home 
Depot. That one turned to to  be a lightning arrestor also. He said that that 
fellow was a pretty nice guy as  well. 


73,

Jim Studer, AK4I