Bill, you don't say what model TIC you have but I'll assume it's a model
1022. Where is the motor mounted? Near the spring-loaded roller bearing?
Or near one of the other two non-spring-loaded roller bearings? If it's
near the spring-loaded bearing, bad news. Your ring could slip in even
modest winds of the correct direction. If the motor is mounted near one of
the other two roller bearings, the non-spring-loaded ones, it is opposite
the spring-loaded one and that combination will hold the ring from turning.
I have three model 1032s on my heavy duty AB-105 tower. I use two motors on
two of my antennas and one on the other. Once I moved the motor on my
single-motor ring away from the spring-loaded roller bearing, I didn't have
any more problems with non-powered ring movement.
I seriously doubt that the 160M RF could cause the DC motor to energize,
especially since the TIC design utilizes a short circuit (at the rotor box
in the shack) to be placed across the motor windings when the unit is off
(power off and non-rotating with power on), thus utilizing the stator magnet
to hold the motor in place. That's why you need the wire gagues that TIC
specifies for the rotor wire! I will assume you have the correct size (or
larger diameter).
Additionally, I would be concerned that the "preset" lamp lights when you
transmit on 160! I have a 160 M inverted "V" mounted to the upper TIC ring
on my tower @ 134 ft. The feedpoint insulator of the "V" is attached to one
of the extra holes in the TIC bracket near one of the roller bearing
assemblies. I also have PolyPhaser lightning protectors (at the tower base)
on the rotor leads (these are MOVs that conduct at voltages > 30V). In
addition, I have 110V MOVs from each rotor lead to ground near the motors.
And the tower is well grounded, as are the coax cables attached to each
antenna. I would double check your grounding implementation on the tower.
The presence of RF in the shack caused by transmissions on 160 M on a tower
outside the shack is a symptom of bigger potential problems.
Until you get on the tower to look at the situation you won't know for sure,
but I'd say, based on the info here, your problem is mechanical more than
electrical. You don't say, but I assume the rotor won't turn in the other
direction either. If not, you need to determine why. Slippage of the ring
alone shouldn't cause the rotor not to turn. Either something is binding
(coax, other wire, in the gears) or the control cable/motor/control box has
gone bad.
Good luck. I'll be glad to help you via Internet. Give me some more data
to chew on!
73!
Bill, n3rr@cais.com
t 07:07 PM 2/4/96 -0500, AB5YG@aol.com wrote:
>I have a Tic General Tic-Ring rotor on my Rohn 25 tower that turns a Force 12
>4lm 20M monobander (30' boom).
>
>The beam was left at North (center of rotation) last night. I was operating
>160M on high power --- The Tic-Ring preset light always lights when I operate
>on 160M using my tower/sloper antenna ----This has not caused a problem in
>the past----
>
>Well--- this morning I set the preset to 90 Degrees and the rotor did not
>turn!!! I immediately went outside and found the beam had rotated 360
>degrees CW and ripped the balun off the driven element!!!!
>
>There are NO mechanical or electrical stops on the Tic-Ring!!! Good thing
>the balun had 16ga wire -- If the coax had been directly attached the driven
>element would probably had been broken --- I checked the pot in the rotor
>and the cable, and the control unit -- all appears to be normal ---- Is
>possible that my 160M RF was rectified and powered the rotor motor? I don't
>think the gears or drive motor slipped as the winds were only around 20 knots
>--- The beam was rock solid in 65 MPH winds this past summer as well.
> Anyone have this happen to them??? Anyone add stops to their Tic-ring??
>
>Please respond directly to me by: ab5yg@aol.com
>
>Thanks - Bill - AB5YG in Mississippi
>
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