A method and apparatus for interactively tuning a transmitter for use in a monitoring station is described. The monitor includes a voltage controlled oscillator producing a radiowave signal for use as a carrier. The voltage used to control the voltage controlled oscillator is provided by a voltage supply...http://www.google.se/patents/US5629875?utm_source=gb-gplus-sharePatent US5629875 - Method and apparatus for interactively tuning frequency hopping transmitter
