On Tue, 20 Jul 1999 01:21:01 -0400, Dick Green wrote:
> My personal experience and surveys on the reflector indicate that:
> 1. Some T2X rotors do it and some don't. I had one that refused to start on
> the first try every time the temperature dropped below 32F.
~~
> 2. The problem typically does not cause a permanent sieze-up. It can be
> overcome by "rocking" the rotor back and forth ...
~~
> the colder it was, the less
> time it took to stick again. It ranged from overnight to a couple of hours
> (32F to -20F.)
~~
> 3. No one has been able to pinpoint the exact cause. Some speculate that
> it's the grease and swear that changing to low-temp grease fixes the
> problem. However, Hy-Gain switched to a low-temp grease and newer models
> still stick.
~~
> Others think it's the rotor cable length. I tried moving my
> starting cap to the rotor, doubling up the wires on the brake and the motor,
> but all to no avail. Still others speculate that it's the brake wedge
> getting stuck. But most people acknowledge that they can hear the "clang" of
> the solenoid retracting when the T2X sticks.
Sorry for the messy clips, but I was trying to get it down to manageable
size for reposting.
>From what I've read, and what I know from experience, I'm guessing there
are at least two different fail modes, as you have suggested.
Your facts clearly indicate a temperature related problem. I've had
exactly what you describe, including recovery times, etc., with my old
modified (more bearings) Ham-M.
On the other hand, I have a T2X that has not yet seen a winter since
I've had it, and it binds like I've seen described here, and by a friend
who also has one, even at 90 degrees. It also does it without a load,
so it isn't torque related. In addition to doing it without a load (no
antenna, just mast), it has only about 150' of the larger cable on it,
so it isn't loss in the cable.
In my case, I discovered the problem before the antenna system got
installed. Coincidentally, that was right after a fairly long thread on
the topic here on TT a few months ago, so I wasn't too surprised when it
happened.
The new crank up tower was installed, and it was laying over on saw
horses while I installed cables and tied them down. I had the rotor
control at the tower with me, and about 10' of cable between it and the
rotor. It may have been at about 30 degrees of tilt (from horizontal)
when I first tried the rotor, and it hung the very first try. Tapping
the opposite direction and then back instantly cleared the bind. After
I finished with the cables and had tried it several times (with high
percentage of failure), I stood the tower up and tried it again and
noticed it did it much less. This leads me to believe it is a binding
problem in the wedge. The noise it makes when it is hung up sounds just
like a solenoid whose armature has been held from engaging fully. It
sits there and buzzes. Now that the TH-7 is on it, and it is standing
vertical, it does it far less often than it did when it had only the
mast on it and laying on its side.
> Even with the sticking problem, I think the T2X is a great rotor for the
> money.
I agree. I'm certainly glad it came with the used package I bought. I
would rather have my TH7DX or KT34XA turned by the T2X, than to be
trying to use my old rotor. Everything else out there that is any
better is also much more expensive. If the sticking problem were to
never be fixed, I'd still be happy with mine. On the other hand, if
mine DOES have the cold temp problem that I've suffered with on my old
one, I'll be looking for a cure (but not a replacement).
Gary
--
Please notify your ISP if you don't receive this.
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|