Kim Elmore wrote:
> I truly appreciate all the responses!
>
> The 9913 is not wet inside -- I checked this the first time it
> happened and it was dry behind the connector that I cut off. I won't
> get any water ingress into my shack because my run is not continuous
> and because all the 9913 connectors up on the tower are shielded from
> the rain. This is good because digging up the 9913 is simply not an
> option -- that would cost many thousands of dollars because we'd have
> to go through the driveway and wrap-around porch. OUCH!
>
>
Sometimes we find it necessary to use alternate routes for new cables.
Also if you have a paved driveway it is possible to rent a hydraulic
drill to poke a hole through, under the driveway, slide in a piece of
PVC conduit and then the coax.
It sounds like you may have direct buried the 9913. That is one cable
that should not be buried without protection.
> I've had 90 deg elbows fail before (non-Amphenol) but all my barrel
> connectors are Amphenol. I also tested them when each failure
> occurred and each time and they tested fine.
>
>
I've had all kinds and brands of connectors including Amphenol fail.
About the only ones I haven't had fail were on the Heliax.
> I used good, old-fashioned Kester rosin core Sn/Pb solder, of which I
> should have enough to last the rest of my life. I'll avoid lead-free
> solder to my ;ast breath!
>
I had connectors on a $3,000 plus HDTV fail due to the RHOS compliant
solder. Fortunately it was under warranty and it didn't cost me a
cent. They sent out a service man who used good old fashioned (non RHOS
compliant) solder to fix the problem.
> I know that PL-259s aren't waterproof, but decided to not wrap them
> having read that more often than not water gets in anyway and gets
> trapped, never able to evaporate. But, I'll freely admit that this
> might be misguided. I have a fair supply of Scotch 33+ tape and, as
> soon as it warms up (it's 16 deg F as I type), I'll wrap all the connections.
>
>
This is a mixed bag. The coax *will* breathe whether wrapped or not.
However any connections except one end should be weather proofed. As the
double female connectors are not water proof, water can migrate through
them although slowly.
The problem with coax "breathing" due to both temperature and barometric
changes is it can breath in moist air from either the house on one end
or nature on the other. Then as it cools that moisture can condense.
It's also a reason for not using flooding compound in any splices
between either end of the cable.
My preference for 9913 was to thoroughly seal the top end of the coax,
weather proof all connectors but not to flood them and leave the
connector in the house open, or unsealed. That is because the air in the
house it *usually* much dryer than that outside unless you run a
humidifier or cook for a big family get together.
> Finally, I didn't positively determine if the failure was in the
> braid connection or the center pin connection in the most recent
> case. The prior failure was about a year ago and, in that instance I
> cut off the connector and found that it was the center pin connection
> that failed, even though I could not move the wire in the connector.
>
I've found some center connectors to be under size, the female end to be
over size, or a combination of the two. I've even found name brand
connectors with out threads, but that is rare and no quality control is
perfect.
When burying cable I'd be sure to use cable rated for direct bury "by
the manufacturer" and not the distributors literature. I've seen LMR
400 listed as direct bury, but I'd certainly not rate it as such
although they do have one version, LMR-400DB which is rated for direct
bury. Due to the wide range of possibilities for failure, I'd use
conduit if at all possible. Coax out to a vertical in the back yard is
different. I've always looked at that as temporary at least in my
installations.
73 & Good Luck.
Roger (K8RI)
> 73,
>
> Kim Elmore N5OP
>
> _____________
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