[RFI] Solar Panel RFI

[nm8rmedic]

My recollection of the article was it appeared some of the chokes were being applied above their self resonant frequency, and/or the high number of turns on the chokes contributed enough interwinding capacitance that combined with the charger's wiring capacitance so some unintended resonance of the wiring emerged, thus the variation in results the author saw.

I think our own Mr. Brown has discussed that unintended consequence several times on this board.   I know I look for it now by sweeping chokes I wind.  (Thank you, sir.)

It looks like this author encountered that, but did not recognize it. 

But, I wasn't there.   And, I know from the article I wrote for an amateur magazine years ago that one's understanding is never complete enough.  So I applaud him for at least writing the article.

Scott


Sent via the Samsung Galaxy Note® II, an AT&T 4G LTE smartphone







<div>-------- Original message --------</div><div>From: Jim Brown <jim at audiosystemsgroup.com> </div><div>Date:08/10/2016  3:54 PM  (GMT-05:00) </div><div>To: rfi at contesting.com </div><div>Subject: Re: [RFI] Solar Panel RFI </div><div>
</div>Hi Ed,

It's been long enough ago since I studied it that I don't remember 
details that bothered me, but dim memory is that it was some details 
about the chokes used and about recommendations for specific wiring 
techniques.  I think I also had issues with the bonding strategy. I'll 
go back and give it another read and get back to you. I also objected to 
the general approach of fixing a bad system -- I strongly believe that 
should be the responsibility of the system manufacturer and the 
installing contractor. So I believe that what SHOULD have happened was 
that the vendor's feet should have been held to the fire.

What's really good about the piece are: 1) the recognition of the 
interconnected wiring as a magnetic loop, something I've been 
evangelizing about for at least 10 years since I learned about it from 
Neil Muncy (ex-W3WJE, SK) about 15 years ago in the context of baseband 
and RF interference to audio systems. 2) the use of twisted pair for all 
wiring carrying significant currents to kill the magnetic field produced 
by noise (another thing I've been evangelizing about for at least 20 
years); 3) the recognition that twisted pair is needed for both DC and 
AC wiring in these situations because those circuits carry RF noise; 4) 
use of ferrite chokes to suppress the common mode component; and 4) how 
much it takes to kill RFI from a bad system.

73, Jim K9YC

What On Tue,8/9/2016 3:42 PM, Hare, Ed W1RFI wrote:
> < Not everything in it is right, but most of it is.>
>
> If there are any errors in the article, Jim, let me know what they are and we can see if it merits a Feedback.  Or I may see it differently than you. :-)

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