[Vitruvius]

You will need two wires for power and two wires for the controling signal to move the motor, in addition to the coax cables.

This is what I put in a 1-1/2" pvc conduit 5" below the ground to my pole mount: 3 coax (spares for future), one ganged wire of 5 (qty.) 18ga. wires running 150 ft. I checked the gauge with an electrical engineer friend of mine who stated the 18 ga. would work but be at its limit. I think 16 ga. would have been ideal. I can post the calculations if you like.

I have heard of some people just using telephone wire for the signal wire, but the 18 ga. does just fine for that.

This is easier to obtain than ribbon cable, but the advantage of ribbon cable, I think, is that you can bury it without conduit.
Rainman, is that correct?

Some people like to use electric wire that can be direct burried, like coax cable that can be direct burried. But I think that is limited to 12 ga. I suppose I would have done better to use 14 ga for the power... but didn't. It would have put less wear and tear on the wire itself.

good luck.