What about putting something over the rotation loop coax? How about the
corrugated black plastic wire loom covering? Or better, maybe a cloth cover
made from sun resistant awning material. Even I could sew up something as
simple as that, just one long seam. Alternatively you could just loosely
wrap the cloth around the coax and secure with an adhesive, maybe securing
with string around it in several places to hold it together while the
adhesive is setting/curing. Maybe contact cement and no wait after putting
it together. worried about longevity? Put on two or more independent
layers. The second layer won't begin to degrade from the UV until the first
layer fails. Ditto the 2nd and 3rd. Good sun resistant awning material last
for years in the sun and weather.
There is flexible corrugated looking spiral wrapped aluminum conduit that
flexes very easily, enough to handle the flexure required of a properly
constructed loop. A bonus would be that the aluminum doesn't transmit much
UV through to the coax jacket. The spiral wrap flexible aluminum conduit is
not water proof (don't get the type with the plastic coating as it is much
stiffer and will hold water.) The Flexible aluminum conduit will drain and
not retain water.
Comments?
P.S. The 40 ft tall tower with 14 ft plus leg separation disassembly
project has been on hold while I assist an older ham get up an antenna mast
to get his antenna up almost 40 ft. Also the series of sprinkles and cold
winds have been discouraging. I did manage to make the trip to the site
twice, once to clear brush and 30 years growth of trees with trunks and
branches intertwined in the tower's X braces and a second trip with a
tractor to push the brush and downed trees out of the way so I can get in
with my trailers, tractor, and truck. As promised, I'll have pix when this
project moves forward. I have two other towers on the ground waiting for
bases and to be put up. I am anxious to get my hex beam up so I might
install one of these before I take the BIG ONE down.
73
Patrick AF5CK
-----Original Message-----
From: Cqtestk4xs@aol.com
Sent: Wednesday, March 27, 2013 7:57 AM
To: TOWERTALK@contesting.com
Subject: Re: [TowerTalk] LMR degradation
Like I said in my post I've been using regular LMR 400 for years on many
antennas. Never had a failure if you leave a good sized loop.
Bill K4XS
In a message dated 3/27/2013 2:37:48 A.M. Coordinated Universal Time,
gary_mayfield@hotmail.com writes:
What are you supposed to put around the rotor then?
73,
Joe kk0sd
From: Cqtestk4xs@aol.com
Date: Tue, 26 Mar 2013 11:42:22 -0400
To: TOWERTALK@contesting.com
Subject: Re: [TowerTalk] LMR degradation
Back in the early 2000s I had a long conversation with the guys at
Times.
The ultra flex on many of my jumpers had cracked after only a couple of
years in the FL sun. His response was the ultraflex was not supposed to
be
used outside.
He offered to replace the stuff with regular 400 but I never took him up
on it.
I use the regular LMR 400 on all my jumpers and have had zero problems.
Bill K4XS
In a message dated 3/26/2013 1:25:47 P.M. Coordinated Universal Time,
k8ri@rogerhalstead.com writes:
On 3/25/2013 2:31 AM, Jim Brown wrote:
> On 3/24/2013 9:42 PM, Jim Hoge wrote:
>> Today I discovered that I have had environmental ingress beneath the
>> outer jacket of some ~8 year old LMR-400.
>
> In the latest (I think) version of his excellent Managing Interstation
> Interference," W2VJN notes that he observed degradation in the measured
> performance of stubs made of LMR400 that had been sitting in his garage
> for a bit less than a decade. He seemed to think it was due todegraded
> contact between the foil and braid shields. This was written several
> years ago. He may have more to say about it by now.
We've known for years the UF versions of the LMR cables deteriorate out
in the elements. It follows that they'd possibly do so with age as well.
I found that the braid had almost disentegrated in some pieces of
LMR400UF where the jacket "appeared" to syill be in good shape. I
thought perhaps the jacket had become porous, but perhaps not?I wonder
which LMR400 he's talking about.
73
Roger (K8RI)
>
> 73, Jim K9YC
> _______________________________________________
>
>
>
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