On 11/12/2017 1:49 PM, Bob K6UJ wrote:
What I did was make sure
the driver tube was well lubed with Penetrox and slid it out in 1/2 "
increments tillit got down where it was good down in the CW end of the band
Of course. But the tricky part is being able to rig the antenna so that
SWR can be measured at sufficient height to remove ground influence on
the tuning AND the so that it can easily lower it for adjustments. Or
access the adjustments from a tall A-frame ladder while it's in the air.
While adjusting a very different 4-el for 10M, I found that the
frequency of lowest SWR went DOWN as I raised the antenna, contrary to
what usually happens with a simpler antenna like a dipole.
A rigging method we often use for portable operations like CQP, 7QP, and
FD uses the 4-ft 2-in o.d. surplus military mast sections in combination
with a tripod base fitting. If the "legs" are two elements tall,
additional mast sections can be pushed up through the center of the
tripod fitting. We use this to get a C3SS up 20-25 ft. We first learned
of this method from a talk that K7JA did at Visalia several years ago.
73, Jim K9YC
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