n3jpu@speakeasy.net wrote:
>I am going to upgrade my 50 and 144Mhz antennas and will also >put new coax in
>place.
>How would either version of the Heliax stand up to the >occasional action of
>cranking the tower down? I know that the >spec on bending either heliax is 50
>but not sure how that >compares to looping 20' or so as the tower nests. My
>concern is the life expectancy of the Heliax vs LMR-600UF.
Hello Gary,
I have good experience with 1/2" Heliax on crankup towers.
My tower is 30m high and cranked down not more then 3-4 time
the year like yours.
The cables feed directly the antennas, no pigtail.
I use generous loops around the rotator, the cables are running
through a piece of pipe near the upper end and are fixed ther to the tower
several times, from there just tangeling down.
I use that installation now for 5 years with different antenna
setups, from 20m monobanders through some for 15 and 10 and
now 2m and tribander TH7.
So far there was never a problem with those cables (2 runs).
I also used a 30m long 1/2" cable for VHF/UHF portable use on a tubular mast
for more then 20 years ( 3-4 times/year), antennas at 12m high direct fed by
heliax, large loop, and tangled from the rotor position to ground, also never
any problem
Concerning life expectancy of heliax I see no problem there either, I use it
for all my installions from 1/4" to 1 5/8" for
30 years from HF to 13cm
Cable in use are made by Andrew and RFS
73
Peter
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