Television tuner circuit for selection of vhf and uhf/vhf converted

Abstract

A VHF television tuner circuit for selection of a television signal through mechanical selection of inductance coils comprises a first terminal for receiving a VHF television signal comprising a high and low VHF channel signals; a second terminal for receiving a UHF/VHF converted television signal; a mechanical channel selection switch arrangement for selection of a plurality of channel positions by rotation of a channel selection shaft said mechanical channel selection switch arrangement comprising a radio frequency coil switching stage and an oscillation coil switching stage; a radio frequency coil means coupled to the radio frequency coil switching stage; an oscillation coil coupled to the oscillation coil switching stage; a radio frequency amplifier coupled to the radio frequency coil switching stage for selectively amplifying a desired radio frequency signal; a local oscillator coupled to the oscillation coil switching stage for providing a local oscillation frequency, the frequency of which is different by a given frequency difference from the selectively amplified radio frequency signal; and a mixer responsive to the radio frequency amplifier and the local oscillator for providing an intermediate frequency signal. The radio frequency coil switching stage comprises a first stage radio frequency coil switch for selectively grounding or disconnecting the transmission path from said first terminal and for selecting a radio frequency coil corresponding to each VHF channel, and a second stage radio frequency coil switch selectably connectable to the radio frequency coil selected by the first stage radio frequency coil switch for selectively connecting said second terminal to said radio frequency amplifier, and for selectively connecting various capacitors in various ways to form a resonance circuit for selecting a desired radio frequency.