Television transmitter

摘要

A television transmitter particularly suited for use in a multipoint distribution service television transmitting system for low power transmission within a limited geographical area. In such a system several transmitters can utilize a common set of reference signals to determine the carrier frequency of each transmitter. The transmitter includes a television modulator for modulating an applied video signal; a local oscillator circuit for generating a local oscillation signal, and a converter for converting the local oscillation signal and the modulated video signal to provide a television transmission signal. The local oscillator circuit receives a video signal to control the frequency of the local oscillation signals, for example in accordance with a characteristic of the color burst signal within the received video signal. The applied video signal can be the same as the received video signal or can be another television transmission signal. The television modulator can control the frequency of the modulated video signal in accordance with a VHF reference signal which can be another television transmission signal or can be a generated VHF reference signal the frequency of which is controlled by a parameter of the received video signal.