One thing I get a lot of
requests for is a way to rigidly mount an antenna made with ladder
line for mast or tower mounting. Most people want to mount the
antennas inside pvc.
This makes them extremely hard to tune
because the dielectric constant of pvc is anything but constant hi hi and
usually detunes the antenna drastically at VHF/UHF frequencies.
I
have developed a solution that may not be the prettiest but is definitely
usable. I call it the "bow" and anyone can build one.
It consists
of a piece of 3/4" pvc about a 6" longer than the antenna, two 90 degree
elbows, another foot of pvc and a few zip ties.
Basically you
drill holes in the ends of the long piece of pvc and bow it to the length
of the antenna and zip tie the ends to the holes you just made. See
picture below .
Affix the elbows on the bottom to bring the short piece
parallel with the antenna and you have a rigid mount that will not
interfere with the antenna's tuning. Here is a photo of mine on my tower
below. That's it on the top.
I'll tell you what...... that thing
really talks up there! I have worked repeaters over 100 miles
away.
The antennas (450 ohm ladder line VHF/UHF "Slim
Jims") are available on my website with an assortment of
different connectors and with or without long coax cable. The VHF only
antennas are custom tunable from 130 - 225 mhz at no extra charge. See
details at my webstore at the link below for more
info.
Thank you for your interest in
my antennas and the "Bow".
Joe
N9TAX
This link will take you to my
webstore where you can buy
one of the antennas. See the review of them here on
Hamuniverse.com.