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Re: [Amps] RF in the Audio

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Subject: Re: [Amps] RF in the Audio
From: "Paul Christensen" <>
Date: Tue, 27 Sep 2011 07:45:57 -0400
List-post: <">>
> On 9/26/2011 6:58 AM, Paul Christensen wrote:
>> Even if the line is truly balanced, that balance would exist in
>> transmission, but not necessarily in receive.
> Paul,
> It isn't as simple as that.  The ANTENNA is also part of the balance
> equation, and if the antenna is unbalanced, it will cause imbalance in
> the line...

Good points Jim.  However, if the line was truly balanced for the entire 
distance of the open-line feeder, then the antenna portion, and its 
influence, is already taken into consideration.  To your point (I think), 
this condition never exists with an HF dipole except in theory as uneven 
placement (even if slight) of the radiator to the line as well as mutual 
coupling effects to other objects will have some influence on line balance.

The reason I said "for the entire distance" of the open line feeder is that 
line current may appear equal when measured at the bottom of the feeder, but 
coupling from one conductor may cause a third current path mid-way on the 
feeder and cause an imbalance into the radiator.  That's a similar condition 
as the "third current path" on the outside conductor of a coaxial line, but 
is mitigated with a CM choke at the radiator feedpoint.

Paul, W9AC

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