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Re: [Amps] Amp causing RFI

To: "'Mark Schoonover'" <>, <>
Subject: Re: [Amps] Amp causing RFI
From: "Tim Duffy" <>
Date: Tue, 4 Feb 2020 22:20:54 -0500
List-post: <>
Hello Mark:


What you are doing (and suggesting others do) with the AC ground – to break it 
– is not right. It violates the NEC code and is very unsafe.


Please refer to the NEC. What is posted here on the RFI reflector is viewed by 
thousands of hams. We must give proper (SAFE) advice.


Please refer to K9YC’s on line work and to N0AX’s book. There is only ONE way – 
the right way.



Tim K3LR

RFI reflector founder and moderator.




From: Mark Schoonover [] 
Sent: Tuesday, February 4, 2020 8:26 PM
To: Tim Duffy
Cc:; Amps
Subject: Re: [Amps] Amp causing RFI


There can be two paths to ground. One from the back of your equipment to the 
station ground then back to house ground. The other path is from the ground in 
the outlet back to breaker box to house ground  then back to station ground. 
That creates a large loop depending on how much AC wiring involved. 


 I use several of those three prong to two prong AC adapters to break the path 
in the AC ground leaving just one path to ground through station ground. All 
chassis grounds are connected to AC ground so electrical safety isn't 
compromised. Really cleaned up a lot of noise with my station. 


The main video about RFI on my website I drew it out on a whiteboard. It's 
about 2/3 of the video. 

73! Mark KA6WKE



On Tue, Feb 4, 2020, 16:32 Tim Duffy <> wrote:

Hello Mark,

I am confused. What does a connection to earth ground have to do with ground

Tim K3LR

-----Original Message-----
From: Amps [] On Behalf Of Mark Schoonover
Sent: Monday, February 3, 2020 11:04 PM
Cc: Amps
Subject: Re: [Amps] Amp causing RFI

On Mon, Feb 3, 2020 at 7:57 PM Jim Brown <> wrote:

> On 2/3/2020 7:48 PM, Alek Petkovic wrote:
> > ndeed. It has also helped me and most ham friends I know on numerous
> > occasions.
> >
> > Adding a few shallow buried wires to the ground rod has also worked well
> > for me.
> Balderdash. The earth is not a sump into which noise, RFI, and other
> trash is poured. Comments like this bring to mind the infinite number of
> monkeys and typewriters producing Shakespeare.
> 73, Jim K9YC
What having a decent ground does is eliminate the possibility  of ground
loops provided the ground is lifted from the third pin of the AC plug. I
did a comprehensive RFI video on the subject and show how ground loops can
happen and what to do to eliminate them. Quite possibly the #1 cause of
RFI. You can watch the video in the link below.
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