Frequency-skipping system for a signal-seeking receiver

Claim 1

In a signal-seeking receiver which automatically scans a plurality of predetermined radio frequencies and tunes to a received signal having a frequency corresponding to one of said predetermined frequencies, a system for selectively skipping any of said predetermined frequencies, comprising: vAriable tuning means having a local oscillator circuit operable to selectively oscillate at each of a corresponding plurality of local oscillator frequencies, said local oscillator including a corresponding plurality of tuning elements adapted to be operatively connected into said local oscillator individually; clock means for generating a timing signal having a predetermined frequency; sequential switching means responsive to said timing signal for sequentially developing a corresponding plurality of output signals to operatively connect each of said tuning elements into said local oscillator individually and systematically in accordance with the frequency of said timing signal, thereby causing said local oscillator circuit to oscillate sequentially at each of said local oscillator frequencies and at a uniform rate corresponding to said timing signal frequency; signal detecting means responsive to the reception of a signal having a frequency corresponding to one of said predetermined frequencies for developing a control signal; a corresponding plurality of selector switches coupled between said sequential switching means and said local oscillator circuit for enabling selection of those of said predetermined frequencies to be skipped and for developing corresponding skip signals; and a digital logic switching circuit including a NAND gate connected in parallel with the series combination of an inverter and a diode, responsive to said control signal for stopping the generation of said timing signal by said clock means and responsive to said skip signal to override said timing signal and advance said clock means one timing unit so that said sequential means is advanced one step at a faster rate than the frequency of said timing signal.