I got a lot of great messages about how I should proceed and some details on
problems that one would not expect. Some are cable related, some parts
inside the rotor and compatibility of the controller and the length of
cable.
I will not summarize here but will later. The thing decided to work again
and I am planning a trip out of the country, leaving in less than a week.
So, the best will wait until I get bac and the WX degrades( no doubt!).
A big THANKS to you all!!
Related but not a solution, I ordered a new ARCO from DXE as an upgrade,
just cuz. It will get into the mix when I get this other mess untangled.
73 es Happy Holiday.
Al N6TA
From: al.n6ta@gmail.com <al.n6ta@gmail.com>
Sent: Monday, December 11, 2023 5:42 PM
To: towertalk@contesting.com
Subject: Diagnosing a stuck rotator
I find myself in a bind in that my DB36 is not turning when commanded. I
have a 5 year old GH RT21 driving a year old M2 Orion OR2800. I am using
beefy cable due to the 250' run to the positioner. The DX-70 tower, Yagi
and 2800 are new and installed a year ago. It has been working fine until
the problem started.
When I command the R21 to turn to a heading, I get the 'no motion error'.
That means that the controller is looking for reed switch feedback and that
feedback is missing so the voltage to the rotor is turned off. Since I have
had some concern about this RT21, I decided to swap in the backup M2
controller. I got the same basic response: Error 1.
I have been able to pulse the rotator from the M2 box enough times to see
the reed switch open and close, but each test returns the error. But it
seems that the motor shaft is turning or the reed switch would not toggle.
It also indicates the motor voltage is getting to the rotator and the
feedback is getting back. After taking a break from worrying about it, the
rotator suddenly began to respond again, and I could turn it CW and CCW
though it is not calibrated. I used it a couple days, but it has now
stopped responding again. I cannot rule out an intermittent in the cable,
but it would be surprising. It is a long run, broken at the tower base with
easy to inspect connections. The run up the tower is strain relieved at the
top and is tied off to the tower so it cannot wag in the wind. This s very,
very stiff rotor cable. I think it has #13 wires for the motor.
I am left to assume that there is friction in the mast that is too much for
the rotator to overcome. That could be a bad assumption and I would love
that not to be the case. The tower is a DX-70 Tash crank up tilt over with
a tilt plate. The DB36 is about 1.5' above the top of the tower. The 2"
mast goes through a bearing in the tower top plate and down to a K7NV clamp
on the OR2800. The rotor is about 7' down the tower. I think the antenna
weight is on the rotator, not being partially hele by the bearing. I may be
lucky that it is currently stuck such that if I crank down and tilt, the
tilt plate will work and I should get the tower mostly horizontal and the
Yagi boom parallel to the ground. It would get me access to the rotor in
the tower, I hope.
I will add that this same thing happened last May, 6 months into my new
system. I did what I described above, and it suddenly started working so I
just hooked the RT21 back up and have happy until last week, 6 months later.
Before I am asked, the RT21 screen goes dark every week or so. Cycling the
power switch brings it back on for another few days or couple weeks before
it happens again. Jeff at GH thinks I have an intermitted AC issue, but I
doubt it. I changed the AC cord and plugged it into a different socket in
the power strip. Nothing else on the strip had showed an issue so I have
just ignored this for now. It has been happening for months. I do not
believe this relates to the rotor stuck issue since the M2 box does not fix
the stick issue.
So, have I committed a tower sin in the way I mounted the DB36 to the
rotator that could cause a binding or some kind of friction that the
motor/controller cannot overcome?
Any comments welcome!
Al N6TA
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