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[TowerTalk] wire antennas (RF resistance)

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Subject: [TowerTalk] wire antennas (RF resistance)
From: (Jim Reid)
Date: Fri, 04 Jul 1997 10:33:26 -1000
Aloha to all on this 4th of July,

Well,  you guys were trying to frieghtn me,  weren't you?
All this talk of lower efficiency and losses in long
wire antenna runs.  And here I am now,  as of yesterday,
the owner of four reels,  each with 600 feet of conductor
for my 4 soon-to-be V-beam legs!!

Press Jones,N8UG and The Wirman,  persuaded me to use his windowed,
300 ohm twin lead, #18 AWG  conducotr wire for each leg,  with
both sides of the twin lead of course,  shorted together
at each end.  The conductors are 19 strands, copper clad
steel with polyethylene-clad windowed insulation.  Press
recommended this for nearly 600 foot long runs,  under
potential tropical storm (sometimes, hurricane) force wind
situation,  rather than his #12 AWG, 19 strand antenna wire
with over 500 lb break strength.

Press also instructs,  that for better strength,  the windowed
300 ohm line be twisted 180 degrees every two feet of run, or
about 300 times should I be able to get all 600 feet strung.
But,  when twisting,  the overall physical length covered will
be less,  I have no idea how much shorter.  However,  the conductor
length will remain constant.  Anyway,  for the V-beam, absolute
length is not critical,  BUT each leg must be equal,  else the
phasing will not add up to the expected patterns.  Guess I won't
worry about this,  as I have no idea how to put in 300 turns
exactly on four 600 foot lengths or wire!!  Will just string it
out as it pulls off the reels.

Had great plans for more rope,  and maybe conductor stringing
today,  but alas,  once again we have had morning showers.
Doesn't sound as if that is a big deal,  but wait until you
have been climbing around in a hau thicket, or wading in 4 foot
tall grass,  all of which is still ringing wet (humidity is
too high for the grass, limbs,  leaves to dry away much).
Soon you might as well be dipped in water as you,  your cloths,
shoes, boots,  etc are all soaked!!  Great mosquitoe bait also.

Hoping for just enough wind,  with some sun for the next few hours
to dry things out;  then the wind can drop while we do some arrow
and string shots,  and attempt some more work thru the "jungle"
behind and in the ravine below.

Somtimes progress can be slower than desired.

73,  Jim, KH7M
Near the South shore of Kauai

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