Abstract: A tuner includes a channel or target frequency selection means, a tunable oscillator, a tunable circuit means having at least one tunable circuit, and tuning means, responding to the target frequency select means, for automatically and individually tuning the tunable circuit. Typically the tuner includes several tunable circuits, which are tuned successively.The illustrated embodiments have three individually controlled varactor tuned circuits and a varactor tuned oscillator. To move to a new target frequency, the tuner locks the oscillator to the target frequency via a phase locked loop. This target frequency is inputted to the first varactor tuned circuit, and a microprocessor cooperating with a DC detector for sensing the output of the set of tuned circuits steps a voltage step generator which controls the first varactor tuned circuit while the tuning of the other varactor tuned circuits is held fixed.

Abstract: A control system is described for use in a television receiver adapted to receive multi-band television signals and which has a direct-access type tuning system. In such a tuning system, the receiver employs at least one local oscillator, the output of which is applied to a prescaler for dividing down the frequency of the oscillator signal. Frequently, the oscillator signal fluctuates in amplitude as the oscillator is tuned from channel to channel and from one frequency band to another frequency band. To compensate for such amplitude fluctuations, the control system confines the amplitude of the oscillator signal to an amplitude range which the prescaler can reliably handle and applies the amplitude-controlled oscillator signal to the prescaler.