The Barrett 4011 automatic antenna tuner is designed for operation in both land mobile and base station installations. Housed in a fully weatherproof enclosure the 4011 will efficiently tune long wire antennas up to a length of 10 metres, wire loop antennas or whip antennas over a frequency range of 2 to 30MHz. Tuning is rapid, typically less than one second from the first time RF is applied, either whilst the operator is talking or when the “Tune” control is activated on the transceiver. The 4011 tuner features a memory facility that stores the configuration required to tune to a frequency. On any subsequent use of that frequency the 4011 reconfigures to the stored settings in typically less than 130 milliseconds. Following initial tuning the antennas VSWR is monitored. If any significant variation occurs the 4011 will re-tune the antenna automatically.