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Re: [TowerTalk] Ecoflex 15 questions

Subject: Re: [TowerTalk] Ecoflex 15 questions
From: K8RI <>
Date: Thu, 19 Jan 2012 15:45:13 -0500
List-post: <">>
On 1/19/2012 2:50 PM, Doug Turnbull wrote:
> OMs
>       I am wondering just how flexible Ecofllex 15 coax may be.   Can I use
> this coax successfully for a rotator loop of about 3.5 feet taking 7.0 feet
> of coax without causing the coax difficulty?
Some where they should have a data sheet for the cable.  In it there 
should be a "minimum bend radius" for both repeatable and non repeatable 
bends. Compairing this figure against other cables the same size should 
give a direct answer to this questions. If you can not find a spec sheet 
I'd call the company and ask them.
I use 2 to 3 turns around the top of the tower at roughly an 18" 
diameter  or Pi*D or 3.14 * 18 =  56 1/2 inches or 4.71' per turn. so 
that is just over 14 feet of coax in my rotator loops.  With this type 
of loop there is very little movement or bending of the coax when the 
mast makes a full turn. It acts much like an over size watch spring.

>    It is a much less flexible
> coax than RG-213 but I am able to provide a fairly loose loop.
>        The centre pin is not soldered on their special PL259 plug but instead
> uses a compression fitting.   Does this present a problem?   For that matter
> the braid is not soldered either but uses a compression fitting somewhat
> similar to that of a Type N connector.
I've never heard of "Ecoflex 15" so I had to look it up. The specs look 
reasonably good, but it bothers me that they say nothing about UV 
resistance for this cable and emphasize it for the "Aircom" versions. I 
would hope the UV resistance applies to the Ecoflex as well.
Virtually all common coax connectors come in crimp versions. Normally 
there is nothing special about them.  Here I use crimp-on UHF and N 
connectors on every thing from 8X to LMR-600. LMR-600 is the only one 
where the UHF connectors are clamp instead of crimp as those connectors 
run around $70 - $80 each.  Eventually I plan on changing to 7-16 Din 

But as to the question of a rotator loop. I've used standard LMR-400 as 
well as the flexible version for rotator loops and if need be would even 
use standard LMR-600  BUT and I have to emphasize that "BUT" I use a 2 
or 3 turn rotator loop, not just a piece of feed line hanging down. That 
means some sort of support is needed for the rotator loop. On 45G the 
flat top plate is large enough that it will serve as a support loop for 
2 or 3 turns of LMR 400 or 600.  The top plate on the 25 G is just a bit 
too small for those but large enough for most of the standard coax 
cables with a stranded center conductor.

So, yes, under the proper conditions virtually any standard cable can be 
used as a rotator loop. However for ease of use and longevity I'd use 
Davis BuryFlex (RG-8/LMR-400 size cable) which is very flexible, has a 
very tough and slippery jacket, is easy to work with, and is just plain 

As a side NOTE:  I do not use the flexible versions of the LMR series 
outside as they have poor UV resistance, the jacket is easily abraded, 
the jacket is rubber like and easily catches on corners or even a piece 
of extra galvanizing.  Depending on the stripper the jacket can also 
"bunch up", unlike the regular versions of these cables.  The regular 
versions are easy to work with and stand up well.  I had 5 pigtails on 
the antenna array which also served as rotator loops. All failed in less 
than 8 years. One piece actually had a split in it over a foot long. One 
piece looked good but had lots of flat spots worn on it so I thought I'd 
use it for jumpers.   In a 28' long piece nearly all of the braid showed 
corrosion.  I have a bunch of LMR-600 UF which is now only used in 
conduit or for jumpers in the shack.

73 and good luck,

Roger (K8RI)
>   Has anyone experience with this
> coax and what is the verdict on these connectors?
>         Thank you for your advice.
>                          73 Doug EI2CN
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