[RFI] CASE HISTORY - Powerline - Multiple Sources

[Charles Plunk]

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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