[NLRS] Variable capacitor

[Dr. Gerald N. Johnson]

Synthetic grease or oil in gear boxes and bearings helps cold weather 
activies a great deal. Like Mobil 1 0W20. But the seals and gaskets need 
to be very good to keep it from running out. Its probably worth the 
bother to go to motors several times larger than needed for warm weather 
to have enough torque to overcome those cold weather stiffnesses. Maybe 
even to go so wild as using a TV antenna rotor for turning an air 
variable. There is one now that uses a run of RG-6 as the control cable. 
It allows for RF from a receive antenna (and passes power to a preamp, 
+18 volts on the coax from the rotor to the antenna. Its not rated for 
transmitter power on the coax and the control unit's switching supply 
puts hash across 6m and some on 2m even when its nominally off, so I was 
using with an outlet strip so it was easy to remove AC when I didn't 
need antennas rotated. I seem to have stripped the gears in the rotor, 
I'll get it down soon and see why it doesn't rotate anymore, but shows 
it has on the control. About $79 on line. It rotates 450 degrees in 1 
degree steps.

73, Jerry, K0CQ

On 9/6/2011 8:10 PM, kg0vl at aol.com wrote:
>
>
>      Good evening.
> Has anyone in the group worked with remote-driven motorized variable
> capacitors?   Cold wx and gear reduction seems to be the biggest issue.
>     Several years of old cassette motors deemed problematic, and was
> looking for something different.  Any outlet on roughly a 400pf device
> to withstand the cold and be controlled from the shack?
>
> Thank you for your time.
>
> 73, de KG0VL
> Jeffrey
> (still at exile in Fairbanks.   Well, Fairbank, Iowa actually)
>
>