What Does Time Do to Wire?
In another recent post Neil Radio8Z mentioned some cable connecting his outdoor transmitter had deteriorated because it wasn't rated for outdoor use.
I had a similar experience one year when I decided to light 3 blue light bulbs on the outdoor bamboo tower for the Winter Solstice. I used indoor type lamp cord to deliver the 12 VDC and it worked fine, but after a year or two I noticed the wire was visibly decayed.
That lamp cord had a transparent plastic insulation so the copper inside was visible, and it had all turned green. It looked very raunchy.
This weekend I was reminded of all this when an XLR microphone cable that had served since the late 1960s went bad and examination showed dried rubber insulation and very puny blackish wire inside that didn't look healthy. A crack in the insulation of one microphone wire opened it to shorting with the shield.... or, maybe an internal wire had simply broken.
We have a ton of extra-long heavy-duty professional XLR cables from our decades in professional recording but it's all in lousy condition even for being stored indoors.
KDX Worldround Radio has discovered that wire and cables have a certain shelf-life, whether indoors or out, and eventually need to be replaced.
Hey, Clare, I believe you're on target sir also UV/sunlight coming into the window will break plastics down much faster than hidden in shelf outta sunlight and extreme temps.
Outside I see it more and faster, of course, Depending on if Nicks got into the cable then moisture and the harder the wire case the better, I remember taking down several old ham installations with rotor cable and coax and all the wire had a green/black look to it so if you have several splices etc the solder prob has broken down and the copper has turned to green/black so conductivity between the unspliced sections is ok but connectors/soldered or screw/plug or really anything of a connection point will start breaking down, so the fewer the connections, and splices and the more long runs without connectivity the better sir...!!!!
Joe
The Radio Dood
www.radiokoiw.com
The best choice is to run your high power and low power in separate conduit. Yes it costs something, but maybe less than re-wiring your job. Personally speaking, I hate to do a job twice unless being paid.
Conduits are useful in large communications installations which remain in one place.
True, in the 60s, 70s, 80s and 90s we had a recording studio that used conduits for wiring.
However we also went on location, which amounted to indoor or outdoor places where plenty of cable got laid out but the main problem was to keep people from tripping over it. Conduits do not get put in temporary setups.
Now it's the second decade of the 21st Century and KDX is built on a very small scale with equipment mostly within a few feet, but we're still using the old XLR microphone cables from the former business.
Because of the overly large size and deteriorated condition of the old mic cables the time has come to re-cable the microphones with fresh shorter length cable.
I'm not inclined to do it anytime soon, so our capacity for originating live programs is closed for now.
Watching black and white film noir movies is much easier.