Before revision: In electronics, a Lecher line or Lecher wires is a pair of parallel wires or rods that were used to measure the wavelength of transmission-line waves, mainly at VHF, UHF and microwave frequencies.
After revision: In electronics, a Lecher line or Lecher wires is a pair of parallel wires or rods that were used to measure the wavelength of radio waves, mainly at VHF, UHF and microwave frequencies.