Hi, the following is a copy of a submission a few minutes ago which I made
regarding rotor loops. This also includes info on the above subject:
Hi TT'rs,
Any of the Times UltraFlex outer jackets use TPE (thermoplastic elastomer). TPE
is not good in UV for much
more than 6-9 years, depending on the ambient. That's too short for
effective/cost efficiency. Even the Times literature states "life expectancy in
excess of 10 years" (discount the "in excess of" ! ) The std. LMR jackets
are PE and so is Bury-Flex Tm (Tm and design of our company). The PE formula I
use is best and it is not subject to UV degradation. Also, it is highly
abrasive resistant due to its sufficiently high durometer, unlike PVC.
Bury-Flex Tm (Low loss) has a life of 30 + years. A good PVC jacket should be
UV resistant and a life of 18 + years.
There often is way over -concern and overkill as far as use of Ultra Flex for
rotator loops. Substitute in a loop of Bury Flex Tm or even 9913F7 ( Bellflex
Tm blend of PVC which is highly UV resistant). Why use LMR 400UF or 600 UF at
the loop and certainly not all the way up the tower from the shack? An
excellent grade PVC, such as Mil Type IIA used in our RG-213 is fine for a long
life and more than adequate flexibility for a loop.
PE outer jackets like Bury-Flex Tm can be laid in water, also highly rodent
resistant, and makes the best cable that I could provide anybody for coiling
around crank up towers...and I sell any cable or wire made, or will design to
your special need.
Hope this is of some help,
73, Steve, K1PEK
DAVIS RF Co., Div. of Orion Wire Co., Inc.
Wire, Cable, RF Connectors and wire aerial parts.
LMR, Heliax, Eupen
Commercial / Military
Custom Cable Design
tel: 978-369-1738 Fax: 978-369-3484
www.DavisRF.com
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