I have a small antenna Rotor, ChannelMaster, that has developed a problem.
The antenna will not turn in either direction. The control box
**pointer** moves around like it is working, but the antenna does not
rotate. I have checked the wires for breaks, etc, and have climbed the tower
to make sure the wires are still connected to the rotor. I have also
checked for binding, and find no problems.

I have checked for voltage at the output of the control box. I get about
40 volts from the common lead to one of the other 2 wires. But,
surprisingly, I also get about 25 volts from the common wire to the other
of the 2 wires, but all the while the rotor control is going in the same
direction !

I would have thought that I should get 40 volts from common to just one of
the other 2 wires (same clockwise) and no voltage from common to the
**other** wire until I changed directions.

So, without buying a new rotor, etc, I would like to see if I can isolate
and maybe fix the problem.

Any ideas on this one, especially comments on whether the voltage tests seem
normal ??

Thanks for any help !!

--James--

"James Nipper" wrote in message
...


I have a small antenna Rotor, ChannelMaster, that has developed a problem.
The antenna will not turn in either direction. The control box
**pointer** moves around like it is working, but the antenna does not
rotate. I have checked the wires for breaks, etc, and have climbed the
tower
to make sure the wires are still connected to the rotor. I have also
checked for binding, and find no problems.

Try a new capacitor. If you can not locate a replacemnet try connecting the
negative leads of two electrolytic capacitors together and connect the
positive leads to where the old capacitor is . Use double the value of MMF
of the old capacitor and a voltage rating equal or greater than the old one.

Thank you, I will try to find one. Would a bad capacitor cause the voltage
to flow on BOTH lines at the same time (clockwise and CC) ?????


--James--

Thank you, I will try to find one. Would a bad capacitor cause the voltage
to flow on BOTH lines at the same time (clockwise and CC) ?????


--James--

James Nipper writes:

I have a small antenna Rotor, ChannelMaster, that has developed a
problem.

Not worth fixing. Replace it with a new digital unit.

On Sun, 14 Mar 2004 23:40:20 -0600, Richard J Kinch
wrote:

James Nipper writes:

I have a small antenna Rotor, ChannelMaster, that has developed a
problem.

Not worth fixing. Replace it with a new digital unit.

Everything is worth fixing if it can be done without excessive cost or
time. If the motor is dead, then junk it, till them try simple fixes.
Yes, 25 to 40 volts is about right for these things.

Everything is worth fixing if it can be done without excessive cost or
time.

Right. My advice is, it won't be worth it. The new units perform much
better, and the additional life to be expected from a repair to this old
unit don't justify the effort, even if it initially succeeds.

None of these replies have answered my question about the voltage being on
both wires at the same time. I would think it would be impossible for
the motor to turn with voltage on both windings (clockwise and CC) AT THE
SAME TIME.


This just doesn't seem normal to me, and I am not sure if the capacitor
would cause this.

--James--

On 15-Mar-2004, "James Nipper" wrote:

None of these replies have answered my question about the voltage being on
both wires at the same time. I would think it would be impossible for
the motor to turn with voltage on both windings (clockwise and CC) AT THE
SAME TIME.

AC voltage on both wires would be normal for an AC two-phase motor. One wire is fed directly with
AC, the other is fed through a capacitor. The capacitor causes a phase shift which determines the
direction of rotation. Your voltmeter will not detect that the two voltages have a phase
difference. If the capacitor is shorted, the two voltages will be in phase and the motor may not
rotate.

Ken Fowler, KO6NO

On Mon, 15 Mar 2004 08:31:34 -0500, James Nipper hath writ:

None of these replies have answered my question about the voltage being on
both wires at the same time. I would think it would be impossible for
the motor to turn with voltage on both windings (clockwise and CC) AT THE
SAME TIME.

I think you are seeing the "return" voltage of the other, not-energised
winding of the motor. The motor, after all, would be acting like a
transformer -- with the "energised" side of the motor being the primary
winding, and the "un-energised" side of the motor being the secondary.

It's just an inefficient auto-transfomer when measured that-a-way.

73
Jonesy
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