6 to 1 balum
50 ohm coax
You may or may not need pulleys at stationary points C & D.
We chose to feed the loop with 50 ohm coax and not ladder line so we could use an SWR meter to tune it. We also think it does not matter where the tunning section is inserted in the loop but that is yet to be determined as is the whole concept.
The winch would likely be mounted on one of the support poles rather than on it’s own pole.
Pulleys 2, 3 and 4 are attached to a non metallic plate which in turn is attached to a non-moving point.