Further, and hopefully final update - found the problem. One of the
motor leads to the rotator had a bad solder connection right at the
connector to enter the shack. It had previous passed visual inspection,
but when I forcefully wiggled it, the wire popped right off the terminal
- I presume it was adhered there only by melted flux. Resoldered and,
for the moment at least, no new cable needed and I'm back on the air!
73, Pete N4ZR
On 7/18/2024 3:06 PM, Pete Smith N4ZR wrote:
Hi Bob - At age 83, postponing the inevitable sounds like a pretty
viable idea.
But seriously, I will be taking a hard look at the cable and probably
replacing it. No direct hits, but had to replace the last rotator and
control box after one nearby a couple of years ago. First time I've
seen water inside a multi-conductor cable, but I have to admit I
haven't looked before.
73, Pete N4ZR
On 7/18/2024 1:57 PM, kq2m@kq2m.com wrote:
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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