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Re: [RFI] CASE HISTORY - Powerline - Multiple Sources

To: rfi@contesting.com
Subject: Re: [RFI] CASE HISTORY - Powerline - Multiple Sources
From: Charles Plunk <af4o@twc.com>
Date: Fri, 24 Sep 2021 11:01:15 -0500
List-post: <mailto:rfi@contesting.com>
I have been day dreaming of a drone with ability to squirt a small amount of water fairly precise on pole hardware as most of these sources vary with humidity/rain. I have not played with a drone yet so do not know if this is practical.

Chuck
W4NBO


On 9/23/21 8:25 PM, Charlie Delta via RFI wrote:
I have been doing a lot of reading on methods to detect and resolve some of 
these more difficult problems with powerline RFI.
There is an amazing amount of information and techniques that can be used that 
goes beyond the typical methods that hams use.
Do a search on the subject of "partial discharge" There are many tools that can 
be used to diagnose these poles and infrastructure.
For example, read some information from this company and others like Doble.
https://www.powermdt.com/partial-discharge
https://www.powermdt.com/sensor-technology

Companies like Doble  and their PDS100
https://www.doble.com/product/pds100/

The technique of HFCT measurement  could be used with a simple homebrew current 
probe. However, I would be very cautious about fiddling around and connecting things like 
a current probe around an arcing poles ground lead. I tried simulating a similar ground 
lead discharge using a Fischer RF current probe and current limited arcing source, and 
it  seems to work. The same goes for a capacitive probe that is nothing more than a 
high voltage coupling capacitor to direct couple the noise.

  The above-mentioned Doble PDS100  is a low resolution spectrum analyzer that costs 20 thousand 
dollars.  Something like the TinySa with a current probe  and preamp and bandpass filter for UHF 
detection could equally with. The specifications on the PDS is worse than those early CATV cable TV  and 
Satellite TV spectrum analyzers.  They are simply using the spectrum analyzer with an an initial spectrum 
scan to establish the background noise floor then they connect the sensors to establish if there is any partial 
discharge activity. There are huge range of readily available scientifice and engineering papers all freely 
available. The powerMDT web page has some good technical information on the discharge characteristics of arcing 
and corona sources that can help identify the sources of such emissions. Companies like Biddle also sell a UHF PD 
spectrum analyser equipment. Even readily afordable spectrum analyzers like the base model Rigol have better  
specifications than these PD analyzers.
I just found some of this technical information on the techniques and measurements very 
interesting. I am not an expert in the field.  There is certainly a lot more useful 
information on these companies web pages than you will find from sources like Radar 
Engineers and the  Loftness book.
73CraigVK3OD

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