Topband: Motor-driven caps

[Barrie Smith]

Well, I'm moving along on shunt-feeding the 70' tower, and would like to thank the many folks that have offered advice.

I would like to control two vacuum caps, and, possibly, one inductor remotely for this project.

I have aquired, and just tested, four motor-drives with geared 10K, ten-turn pots, which are surplus, and designed to turn vacuum variables.

There is no protective method in the units to prevent over-turning the pots.  Without some means to limit travel, I'm sure that some sleepy night I will go one turn too far.

Anyone know of a plan to stop CCW at, say, 1000 ohms, and then allow CW rotation to 9K, or so?

All this would involve polarity switching in the shack, of course.

Also, I'd like to install meters in a panel to keep visual track of where the caps are.  It's not likely that I'll be able to use the motor supply voltage for this purpose, since I plan on using variable voltage for very slow and faster motor rotation.

Also, even though the motors run FB under load here in the shack at 70 degrees with 3 volts applied, it's not likely they will outside in a box when it's 40 below, so a "kick start" may be necessary.

Thanks, es 73,

Barrie, W7ALW