[TowerTalk] Testing for unbalanced parallel feedline

[Tom Rauch]

> Let me be sure I understand this.
>
> 1) If the meter's probe is large enough to encircle both
conductors, do so
> and measure. The better the balance in current, the closer
the meter reading
> will be to zero.

Yes! That's because the meter will real the true common mode
current.

> 2) If the probe can only encircle one conductor at a time
(such as with
> homebrew 600 ohm line), measure both at the exact same
distance along the
> line. The better the balance in current, the closer the
*difference between
> the two readings* will be to zero.

This is just to give you an idea of the magnitude of
currents so you can see how they compare to common mode
measured in step 1.

> Now for the fun part. I have modified my field strength
meters to have
> female BNC signal input jacks. Can I homebrew a probe from
a split ferrite
> bead and a few turns of magnet wire around one half of the
bead and plug
> that into my field strength meter?

Probably. You should load the current transformer with a
resistance.

I have a brief description of a current meter I built at:

http://www.w8ji.com/building_a_current_meter.htm

73 Tom