On 3/29/2011 8:12 PM, Robert Harmon wrote:
> Roger,
> I have some LMR 600 ultra flex that I will need to do a turning loop
> arrangemet with.
> I am wondering if it is possible to do a 3 or 4 turn coil that is in a spiral
> configuration
> around the mast, then there would be little abrasion Just thinking.........
I had the 400UF as you describe laying on the flat top plate of the
45G for about 5 or 6 years (give or take). It actually had braid showing
in one spot and many flat spots. OTOH it had a number of cracks (up to
an inch long) along the length apparently from exposure to the
elements. I had two pieces that looked good so I was making flexible
station jumpers out of them. I had already made several jumpers before
I found a section where the braid was corroded for several feet
apparently from moisture. I never did find where it got in. This was
pretty much in the middle of a 28' section that was good on both ends.
Possibly had the top plate been painted so it was smooth the jacket
would not have abraded like it did, but that still would not have
stopped the weathering.
In my opinion, the UF cables NEED a cover over the jacket to protect
them/it, particularly in rotator loops but that would reduce the
flexibility. Even several layers of tape *might* work. Yes, I know how
much the 600 UF costs as I have 2, 200 foot coils of unused LMR-600 UF
left...some where. It has the same rubber like jacket as the lMR-400
UF. I have one run of the 600 UF in the conduit between the tower and
den where it's out of the elements. I'll likely use the rest of it for
additional runs in the conduit. I'd use it to the shop as well, but I
already have multiple runs of regular LMR-600 in that conduit.
Had I removed the pigtails *before* I purchased the LMR-600UF I would
never have purchased another batch of the UF. It's a great low loss and
very flexible coax, but it does not stand up well to UV light or
mechanical abrasion. It also seems a waste to put N-type connectors on
the large cable, but most UHF connectors for it cost a small fortune.
73
Roger (K8RI)
<snip>
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