[TowerTalk] Ladderline - what are the facts??/

[Steve Hunt]

Rob,

Unfortunately you wont be sure!

The MFJ meter only compares the magnitude of the current in the two 
wires; crucially it doesn't look at the phase. So when the meter 
indicates "balanced" any one of the following might be true:

* The line is indeed balanced
* The currents are equal magnitude, but the line is unbalanced because 
they are not 180 degrees out of phase
* The line is unbalanced, but the meter is at a null in the common-mode 
standing-wave pattern

The most extreme example would be a line carrying all common mode 
current (no differential mode) split equally between the wires - the MFJ 
would tell you that was balanced!

73,
Steve G3TXQ

Rob Atkinson wrote:
> Anyone
> uncomfortable with these assumptions can get a parallel wire RF amp
> meter from MFJ and check their line to be sure, and try making
> adjustments if the line turns out to be extremely unbalanced.
>