Field Day Antennas --- Sliding Match

Intrigued by the graphic? Visit:
https://www.youtube.com/watch?v=VQ651FUa6GQ

This is a Loop Dipole supported by trees holding Pulley blocks through which the loop is formed. The feed point can be moved along the axis of the dipole, aided by the blocks, to change the impedance presented to the transmitter.

This is a variation of the Off Center fed dipole.

Drive both lines together, and you have a Top Loaded Monopole, which can be offset to achieve a better match.