While true, Mark, I isolated the problem to the bad jumper in a couple
minutes, as fast or maybe faster than getting out the boat anchor HP to
do the TDR bit. I did waste some time comparing good to bad etc mostly
due to my amazement having never experienced such a problem in over 50
years of coax use. I spent a minute cutting the coax to see the
problem. I admit I was lucky that the defective inch or two of coax was
exposed on the first cut but that is reality. I also took some time
putting a connector on the cut ends and testing to see if there were
other anomalous sections but there weren't. I will tag the short
jumpers salvaged after removing the bad spot so if anything "funny"
happens I will suspect them right off.
Lucky trumps good.
Patrick NJ5G
On 12/15/2014 1:27 PM, Mark Stennett wrote:
A time domain reflectometer would eliminate the guess work and show you where
the defect was on the line.
73 de na6m
On Dec 15, 2014, at 13:19, Ray Benny <rayn6vr@cableone.net> wrote:
Patrick,
I had a case once of a shorted coax due to a manufacturing defect. The coax
was a 100 ft piece. I had first cut off the connectors one at a time but
found the coax still shorted. I cut the coax in half, one half open, the
other shorted. I kept cutting the shorted section in half until I had about
a 6 inch shorted piece remaining. I slid off the braid and found that
during the manufacturing process the center conducted was bent outward and
through the dielectric causing a direct contact with the braid. Don't know
why the short was not caught in a QC check, but maybe only random
pieces/rolls were checked.
In the end, I still had 50ft of coax to use, plus a bunch of shorter
pieces...
Ray,
N6VR
On Mon, Dec 15, 2014 at 11:09 AM, Tom Osborne <w7why@frontier.com> wrote:
Hi Patrick
Don't think I'd cut them in half.
I'd just cut the plugs off and replace them and check the cable again.
Might be something in the plugs that are bad and you would be wasting a
bunch of cable.
If still bed, then start cutting them. 73
Tom W7WHY
On 12/15/2014 8:09 AM, Patrick Greenlee wrote:
I'm going to cut the bad jumper in half and test the halves and then cut
the bad piece in half and test those pieces. Whichever is bad will then be
dissected carefully to see, if possible, what was physically wrong with the
coax. This is a real head scratcher for me. The good news is I'm back on
the air with a pan adapter full of signals again and loving it.
Patrick NJ5G
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