English: Wire radio transmitting antenna built by radio amateur William D. Reynolds, 9ZAF, of Denver, Colorado, USA around 1920, which was also the initial transmitting site for broadcasting station KLZ, first licensed March 10, 1922. It is an elaborate inverted-L antenna, which was widely used on the longwave radio bands popular during the early 20th century.

It consists of ten 90 ft. parallel horizontal wires suspended like a "clothesline" between two 80 ft towers. Two 6-strand vertical "cage" conductors feed the antenna at the near end, joining together to a single cage, which drops down to the transmitter. The vertical "cage" line is the radiating element, functioning as an electrically short monopole antenna. The horizontal cables serve as a capacitive top-load, to increase the current in the vertical driven element, increasing radiated power. Using "cage" line made of a cylindrical array of parallel wires rather than a single wire reduces the resistance, which is important at low frequencies, where radiation resistance is so low that a large portion of the transmitter power can be wasted in ohmic resistance of the antenna or ground. Cage line also has higher capacitance to ground, increasing current in the antenna and output power. Cage line is also used for the two outer conductors of the horizontal top-load because they have more capacitance to ground and carry more current than the inner conductors.

The second grid of horizontal wires, lower down on the antenna, is a counterpoise that serves as the ground for the transmitter. The other side of the transmitter's output is connected to it. It functions as a large capacitor plate, with the conductive layers in the Earth serving as the other plate, allowing the RF current from the transmitter to pass into the ground. Counterpoises often work better than physical grounds at low frequencies, when the soil has high resistance.