[TenTec] Ground Loops in the Station

[Bob McGraw - K4TAX]

The only "ground loop" I've ever experienced occurred with a Piper Tri-Pacer 
during a severe cross wind landing.  It is not a question of "will you 
ground loop one, but it is a matter of time when you will ground loop one". 
Minor damage to the craft, other damage reported was to the pilots pants.

73
Bob, K4TAX


----- Original Message ----- 
From: "Jim Brown" <k9yc at audiosystemsgroup.com>
To: <tentec at contesting.com>
Sent: Monday, December 09, 2013 3:42 PM
Subject: Re: [TenTec] Ground Loops in the Station


> On 12/9/2013 1:11 PM, Rick - DJ0IP / NJ0IP wrote:
>> I have read lots of stuff on grounds and it appears to me that there is
>> nothing than anyone says or writes that isn't contradicted by someone 
>> else,
>> elsewhere.
>
> Bill Whitlock, Chair of the AES Standards Committee Working Group on EMC 
> (I am the vice-chair) laid it out quite well. You can study the extensive 
> tutorial material on his Jensen Transformers website. I've adapted his 
> analysis and models to what happens in the ham shack. You can see it in 
> the Power Point pdf on my website under the topic of Interfacing.
>
> k9yc.com/publish.htm
>
> The mechanism that puts AC buzz in our audio is power system leakage 
> currents. It has NOTHING to do with a "loop."  Those leakage currents flow 
> on the green (ground) wire, and the resulting IR drop causes every chassis 
> to be at a somewhat different potential, and that potential consists of 
> the triplen harmonics of the power frequency. The difference between those 
> two ends of an unbalanced connection is simply added to the signal. The 
> interfacing tutorial shows this, and shows simple, inexpensive solutions.
>
> 73, Jim K9YC
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