[Moon-net] LMR 400UF

[Stan]

Hello Bob,

Birds pecking at it, squirrels chewing it, other mechanical abrasion, 
water in the coax,
too much flexing when rotating, az or el, Possibly tie wraps much too 
tight, compressing the inner dielectric
and allowing a flash over from inner conductor to outer shields.

I would replace it with another LMR-400UF piece and be sure to tune the 
antenna it feeds.
Anyone in your circle of friends have a infra red thermal viewing camera ?
Look for hot spots after a WSJT run.

Stan, W1LE   FN41sr   Cape Cod


Bob Baker wrote:
> Dear Moon-net,
>
> I am again in need of your wise, collective advice.
>
> I just had a failure of a piece of LMR400 UF coax. It was only about 2 years
> old. It is clearly blown, SWR terrible, and you can see a small piece of the
> white dielectric sticking  through the black outer insulator.
>
> I have a 2 yagi system, the other coax and antenna are working fine. Same
> coax, same age. swr perfect, looks almost new.
>
> At the time of failure I was running 1500W jt65 144mhz. Measured at the
> antenna, the swr was about 1.3 to 1.4. The most power I could have had in
> the failed coax was 700W and it is rated at 1500W for 150MHZ. But my SWR was
> not perfect in the antenna with the failed coax.
>
> Obviously I need to buy more coax. Has anyone had similar problems with LMR
> 400 UF? Was the cable defective or did I just push it a little too hard? Any
> recommendations? LMR 600UF?
>
> Thanks in advance,
>
> 73,
>
> Bob
> KD3UY
>
>
>
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