[TenTec] [SMC] OT: Half inch Andrews Heliax LDF4-50A vs LMR-400

[Phil Sussman]

Any transmission line is subject to several different stresses and torques.
The longer the line the more effect. While rigid hard line may not be affected
as much as say RG58 or #12 wire, it still must weather the elements when
outdoors.

For example, rigid line up the side of a tower faces the results of weather,
primarily wind and water. Seals and jackets are continually affected
especially at higher altitudes. I've seen wind flex affect 7/8" hard line by
banging it against tower section bolts, even with repeated strapping to the
tower itself. After a number of years the cable was punctured and water
infiltrated the line.

Another source of flex failure is at the connectors which in many cases are
well connected and sealed, but after installation are allowed to flex (only
a little bit - but that's enough) at the top where jumpers are employed.

Just some food for thought. After all, those tower climbers do need some job
security. Hi.

73 de Phil - N8PS

-----

Quoting Barry N1EU <barry.n1eu at gmail.com>:

> On Fri, Apr 26, 2013 at 1:36 AM, GARY HUBER <glhuber at msn.com> wrote:
>> I read a piece about
>> coaxial cable shields with aluminum foil and braided copper, repeated
>> flexing, and moisture which destroys the aluminum and is a diode action
>> noise source.
>>
>
> If you're not using it for the rotor loop, I don't see why a coax run
> would be subjected to ANY, let alone repeated, flexing.
>
> Barry N1EU
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