wa2xrm now has a small reversible high torque 'turbo' worm gear motor on the antenna variometer. The antenna loading coil is outside in the snow. Now i can tune it from inside the control room. It is 0.6 RPM and 12 VDC. Cost $7 from China on ebay. Not sure it will work at -20F but will soon find out. Paul wa2xrm