Just a note to my many friends on this thread.
I have not been responding to everything, but I assure you, I have read all
of this with great interest. I am still a little unclear as to whether I
should insulate the brackets or not to make the original ARRL analysis work
(to the extent that it works).
My current thinking is to stick with the plan as I have it and have one
'break' of insulation and not worry so much about the lower length. I can
react later if there is trouble with more insulators. My tower raising
party is oncoming and I don't have a lot of time to get this done. I am
using the heavy duty ceramic type that I have long seen on utility poles.
In actual fact, as this is my second tower, the initial deployment will be
6m, 30m, and also 432 and 1296. I'm not sure I can do anything about the
latter two except have them up the mast a ways (planned). I do have five
feet between the tallest guy bracket and the top of the tower as well,
though we may place a fixed 6m near the top of the tower as well so we have
stacked Yagis pointing at East Coast and Europe from here.
That makes 10 feet a chancy choice. I think that 11 feet may be the right
length for the section closest to the top for the actual configuration and
also for future configurations. The range for the "classic" ARRL formula
for 6 is 7.8 feet to 10.3 feet.
10 feet is near the edge for 6m by my calculations and 12 feet might be a
24 foot dipole ("tripole"?) that could be bad on 30m and maybe 15m too. I
would obviously like to keep my options open for the future.
Larry WO7R
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