Pete,
Water inside of any cable is an issue - at a minimum it means that the
there exists the possibility of a hole or holes in the outer jacket of
the cable. Has your tower been hit by lightning? A lightning strike
can easily cause heating of the cable which can cause the cable itself
to swell or burst the insulation on the individual wires within the
cable opening it up to shorts, especially as water gets in.
I've had lightning hits here in CT that have caused this problem, with
the rotator control box indicator acting "flakier" and more erratic with
time until it stopped indicating. I eventually replaced the rotator
cable, pulled the old cable off the tower, did a necropysy on it and
found areas of almost microscopic holes in the outside jacket of the
cable leading to water ingress which then allowed water to get into the
strands of the conductors as there were tiny but visible bulges in the
white insulation around the wires where there were barely visible holes.
All of this no doubt from the multiple lightning strikes.
The rotator still worked for months afterwards until the problem grew so
vexing that I swapped out my rotator and took the rotator cable down and
ran a new one. End of problem.
I would be more concerned with any water inside the cable when it gets
cold enough to freeze, because water freezing expands in size as it
becomes ice - so the expansion in volume of the ice will most likely
enlarge any holes/breaks in the cable that you might have. It might
also break individual strands within the wires. Not a situation you
want.
The problem with lightning strikes is that often you can't see where the
holes/breaks might be on the outside of the cable. And then you can't
see any holes/breaks on the inside of the cable because of the outer
jacket. So you may or many not have a problem. But if you do see
bulges or holes/breaks in the cable, then you should replace it.
Otherwise you just postpone the inevitable as the cable will eventually
fail.
73 and GL!
Bob, KQ2M
On 2024-07-18 08:56, Pete Smith N4ZR wrote:
It's hard to say whether the water has anything to do with my rotator's
current failure to turn. Internal insulation looked fine, but I
measured 60 ohms between the two motor leads at the bottom of the tower
- if the rotator is up against the limit stop (as I think it is), then
the limit switch should have opened and there should be no connection
at all. From memory, I think the motor winding should have been around
8 ohms. Looks like the antenna needs to come down to determine where
the problem is...
73, Pete N4ZR
On 7/17/2024 10:23 PM, john@kk9a.com wrote:
I use THHN for the motor wires and a multi-conductor for the sensor.
I try
to seal the cable ends but I do not make a big effort to seal them. I
have
never noticed water in any of my control cables but even if there was,
I
don't see how water inside the PVC cable jacket would effect it since
the
conductors are insulated. If water got inside the connector at the
rotator
it would likely have an effect, this is common with Yaesu rotators,
their
boot does not make it water tight. I have had very few actual rotator
problems but I have had several issues in the last few years with
failed
lightning protectors. Pulse type seem especially sensitive to
leakage.
GL
John KK9A
Pete Smith N4ZR wrote:
I've been having problems with my rotator, currently stuck due west.
Today, in order to verify connection from the controller in the shack,
I
cut open the jacket of the good quality 6 x #18 cable at the tower
base
- imagine my surprise when water flowed out of the cut, even though
all
the cable above that point is vertical.
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