Antennas

Multiband Antenna

  • An antenna about a half wavelength long at the lowest frequency to be used fed with a balanced line of say 450Ω will operate on all the higher frequency bands
  • Impedances at the shack end of the feed line will contain reactance and will vary very much from band to band
  • An aerial tuning unit is therefore essential to “tune out” the reactance and transform the load so as to present a resistive load in the region of 50Ω to the transmitter output stage