Channel selection apparatus

A channel selection apparatus comprising:

• an electronic tuner having a local oscillator which produces an output signal whose output frequency is variable for controlling the tuning frequency of the tuner;
• a sweeping circuit coupled to said local oscillator for sweeping the frequency of the output signal of said local oscillator;
• a surface acoustic wave comb-shape filter coupled to said local oscillator for receiving the output signal of said local oscillator and producing, when the frequency of the output of said local oscillator is swept from a lower frequency to a higher frequency, an output having a comb-shape output characteristic including a plurality of first output peaks which successively appear at predetermined first frequencies which are substantially equal to first predetermined frequency intervals within a predetermined frequency range of the output of said local oscillator and a second output peak just preceding to a first produced one of said first output peaks at a second frequency spaced by a second frequency interval which is greater than said first frequency interval;
• a first detector coupled to receive the output of the surface acoustic wave comb-shape filter including means for detecting the first and second output peaks of said surface acoustic wave comb-shape filter and means for producing output signals corresponding to the first and second output peaks at said first and second frequency intervals, respectively;
• a presettable counter including means for counting the number of peaks detected by said first detector;
• a second detector coupled to receive the output signals of said first detector including means for discriminating the second frequency interval from the first frequency interval and means for producing an output signal indicative of the detection of said second frequency interval;
• and
• means coupled to said presettable counter and responsive to the output signal of said second detector for causing said presettable counter to start counting of the output peaks detected by said first detector which occur after detection of said second frequency interval by said second detector.