Print up the pattern and the prism drawing below. Glue both to poster board and cut the prsim out. Put a paper fastener through the center of the prism and the big circle of the H. pattern. That is your tuning dial. Put the witness of what you want to transmit on the circular coil in the upper left hand corner and the witness of what you wish to target on the square output coil. Set the dial and away you go.