[Elecraft] Coax-Fed Antenna for KX1 with ATU

[Stuart Rohre]

Charles, I don't doubt the OCF even with feedpoint balun will work.
My point was why have the extra weight when the balun cannot change the
inherent balance of the antenna, but only unbalance a balanced dipole to
unbalance of coax?  Trying to balance something that has unbalanced
halves is probably not worth the effort.  Just accept some feeder
radiation, and it may enhance your low angle of take off for OCF users.

There are some who do not have very long feed lines on an OCF and worry
about it being able to be matched to their rig.  With the proliferation
of 50 ohm unbalanced output rigs today, the path of least trouble lies
thru use of center fed antennas.   Hard to go wrong there.  Not much of
a tuner is needed, if you are making bandwide excursions in frequency.

I just quoted Windom himself that the current distribution only works
for his feed at a single frequency and its harmonics.

I suspect the perceived broadbandedness of an OCF as compared to a
dipole may be because of higher losses.  These could be from feedline
interaction with the OCF, the balun, or a combination.  Remember the
most broadband antenna of all is a resistor.  

I have been looking for a basic antenna project to write a paper about
for upcoming ham conventions.  I think I might replicate the Ohio State
"Windom" team's RF current metering set up and measure the current
distribution on a center fed dipole and on a true OCF and the modern
OCF.
That could be a fun little project, say make test antennas on 10m of
each kind, or rig a pulley arrangement to move the feedpoint along the
wire.
Thanks and 73,
Stuart Rohre
K5KVH