Coax under ground has many enemies from all the comments I've read on TT.
Cable TV runs their coax on messenger cables mostly out of necessity. That's
equivalent to going up the tower and to the beam. Has anyone any data on the
damage of even cheap coax in the elements in time if not abused? I've got
some old coax that hasn't leaked water and it still checks good for VP and
low loss. Therefore I'd have to assume that all the problems discussed here
can be avoided by running coax on Messenger Cables to the tower and learn to
live with it.
I still have one length of the original open wire line I made in the 30's
that has seen more sun and rain than most hams have and has carried many KW's
of RF than probably any ham feedline in existence. It's very low loss
characteristics haven't changed--in over 60 years. Open wire line is
advertised in the mags and making a big comeback. Get a Johnson Match Box,
"learn how to use it" and all these "major problems" plaguing the Hams and
filling Reflectors--will just go away. The open wire line will out live you
and be the last one you buy for each application.
The Johnson insulator spreaders from the 30's show up at flea markets from
time to time. I used Delrin but I'm going try the plastic used in plastic
hangers for a very low cost. Wooden dowels boiled in wax is one of the worst
of all. At 600W on 20M I could hear crackling. K7GCO
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