Towertalk
[Top] [All Lists]

Re: [TowerTalk] Current imbalance on 450 ohm Ladder Line

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Current imbalance on 450 ohm Ladder Line
From: K4SAV <RadioIR@charter.net>
Date: Fri, 16 Mar 2007 02:32:33 -0500
List-post: <mailto:towertalk@contesting.com>
I agree with your conclusions Dan, and with your first explanation. 

Since you got me on that one, just for the sake of argument, I will pick 
on your last statement.

..."I think the meter is fine.  There's more current in one leg than the
other because of common mode current,".....

Well not exactly. Common mode current does not cause more current in one 
leg than another.  Common mode current can be a result of the 
differential currents not being equal and opposite, but it is also 
possible to have common mode currents plus have matched differential 
mode currents, although I can't think of a good example of this with 
antennas.  It is more often found in circuits where there is more than 
one source.

Yeah, I know that is probably not exactly what you meant to say.

Jerry, K4SAV

Dan Zimmerman N3OX wrote:

>>. It should be measuring
>>current balance between the two output lines, and this should be only a
>>function of the load.
>>    
>>
>
>If you have a current imbalance on open wire line, you have common
>mode current.  Only in the perfectly balanced case (equal and opposite
>currents) is the line operating with differential mode currents only.
>
>I think the meter is fine.  There's more current in one leg than the
>other because of common mode current, but it's not the antenna's
>fault... the antenna is nice and symmetric (the switching of the
>output leads proves that )
>
>The test described in the original post says that the rig and tuner
>are not symmetrically sourcing current to the perfectly symmetric
>antenna.
>
>Dan
>_______________________________________________
>
>
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>  
>

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>