This is really interesting.
I've been using coax since the mid 50s, including some WWII jumpers made with
poly dielectric RG-8.
I've dug connectors out of the mud, pulled them out of puddles, and found them
in musty basements.
Many were Amphenol milspec and many were not.
Some of my jumpers are cut off feedlines from old CB antennas.
I have adapters and SO-239 of varying quality.
Some of the RG-8 dielectric has gotten fairly hard and turned brownish yellow.
I run up to 1200 Watts, often with several jumpers, wattmeter, tuner, involved.
It's probably a good thing I'm not on VHF.
Now the punchline: I have never had a connector failure!
I've had braid shorts, broken center conductors, and plain forgotten to
solders, but never an arc, melt, or open.
Not to say the advice toward quality is bad. I know it's good, but I find my
story amusing.
It seems to me that a properly operating station should never see more than
about 300V RMS on its coax, so carbon tracks are likely due to contamination
setting up conductive paths, not connector quality.
I regularly run 800W through all sorts of jumpers, including readymade crimps.
My rigs don't have duty cycle problems, so I have made lots of 30m runs, to
look for problems and NEVER been able to get any noticeable warming at
connections.
The lightning mentioned is a good bet, very high SWR also.
For sure, an unterminated T network tuner can arc over most anything! Ask me
how I know.
Quality? Well, I have some Radio Shack RG-8 that has the skimpiest shield I've
ever seen, like 80% coverage, maybe.
I doubt it's a loss problem, but wouldn't want to guess the leakage! This may
motivate me to do a loss measurement.
BTW, an electric stove element makes a fine dummy load, near indestructible, if
you have a tuner that can match to it.
Just some food for thought. It's rainy here in quarantine land and the bands
have been horrible.
Even the DX that's on has been eaten by ft-8, especially on 160m. Being old is
not easy!
73,
WL
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