[TowerTalk] Testing for unbalanced parallel feedline

[Tom Rauch]

> Is there a simple way to test if a parallel feedline is
unbalanced by
> measuring leakage/radiation? Would a simple field strength
meter make a good
> probe for this?


You really should measure current balance at two points on
the line by using a clamp-on meter. I know MFJ sells one I
designed that is calibrated in amperes. It should be OK
since it is surface mount parts, assuming they haven't
mucked it up.

Measure current in each conductor by clamping around each
conductor one at a time and record it. Measure the vector
sum of currents in BOTH conductors by clamping around both
conductors at the same time.

Some people think you can do this with light bulbs or
measuring current in each conductor alone and NOT the vector
sum where both conductors are clamped inside the probe, but
you really can't. I'd do this at the tuner and 1/8 to 1/4 wl
away if possible.

73 Tom