Cut a 3-foot section off the 20-foot pole. Place the 17-foot section in a vice. Clamp the 3-foot section perpendicular to one end of the pole to make an "L." Tack and then weld the two sections together. Grind off the sharp edges on the inside circumference of each end of the 3-foot piece so it does not fray the cable as you wench it up and down to fill the feeder.
Weld the boat winch 5 feet down from the leg of the "L." First, tack the base plate to the pole, then weld the top, bottom and center-line to the outer circumference of the pole on the same side as the hole at the base of the "L." Feed 20 feet of cable from the wench through the leg of the "L." Attach the feeder to the hook on the cable.
Dig a hole that is 4 feet deep and 2 feet in diameter with a shovel or an auger. If dug with a shovel, plumb the sides and clean out the bottom with a post hole digger. Invert the "L" pole and drop it into the hole.
Wire three 2-by-4 inch boards to the pole for support in order to plumb it vertically. Lay the face edge of one end of each board against the pole, 4 feet up from the hole. Angle the boards down to the ground at 45 degree angles. Arrange the boards so they divide an imaginary circle around the hole into thirds in order to act as legs. Wrap wire around each board individually, and around the pole. Pull the wire tight with pliers, then knot the wire by twisting the two ends together with the pliers. Level the "L" pole up and down by adjusting the legs toward and away from the hole while holding the level against the pole, then drive rebar stakes into the ground against the feet of the legs with a hand maul.
Mix three 80-pound bags of concrete with water in the wheelbarrow according to the manufacturer's ratio specifications. Pour the concrete into the hole and allow it to dry for the recommended length of time. Fill the feeder. Climb the ladder and winch the feeder up until it is at or above the height of the winch.