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Old July 21st 07, 06:05 PM posted to rec.radio.amateur.antenna
Ed Ed is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 256
Default Building a marine type HF whip


Question: What would you gain with copper tubing inside your lower
PVC sections. Slight BW increase, perhaps? It seems to me that it
creates an attachment problem, compared to just dropping a single
conductor down from the stainless steel whip, through the center of
the PVC and out to the tuner attachment. Speaking of that, including
a PVC T-connector in the lower section, perhaps a few feet off the
ground, would give you an exit point for the radiating element, but it
would probably louse up the process of storing the whole thing inside
your 8 foot PVC tube (whose diameter is not given).



Sal,

Thanks for your ideas. Regarding the copper tubing issue, I was
thinking of that for two reasons.... good rigidity for the PVC to prevent
flexing, and also perhaps a better radiator. However, in raising the
question, you have prompted me to rethink that issue. Perhaps just
running some braid off of RG8 type coax in the PVC would be better in
some respects, including weight. Will keep pondering this issue.

My other problem will be to find a proper way to fasten/screw the
three elements together.

Perhaps just a PVC flat end cap on the top section with a 3/8-24 bolt
sticking up to fasten the SS whip to the top piece. As far as the other
two 7 1/2 foot sections go, I could simply do as you just suggested -
use a slightly smaller PVC piece at the middle juncture, glue it into
one of the two PVC sections, and simly pull it appart to dissassemble
those two sections. If I run braid down those two sections, I can just
leave it and fold the two PVC sections together to keep their storage
length at 7 1/2 feet long.

..... that would work. Problem is, I like the elegance of the
Shakespeare antenna, but I don't want to pay the price for one!

Ed