A front end tuner for receiving TV signals and the like includes a frequency
conversion
circuit including a mixer for beating a local signal with received signals within
a predetermined band of frequencies to provide selected signals within a predetermined
band of frequencies to provide selected signals within a predetermined channel
band of frequencies. A signal converter circuit generates digitally encoded signal
representations of the selected signals. The frequency conversion circuit and the
signal converter circuit are in a form of an integrated circuit within a semiconductor
substrate. In a TV receiver, on-following digital processing of the digitally encoded
signals is performed in a microcomputer. In one example a channel selection code
is used by the microcomputer to synthesize the local oscillator signal and in another
example the signal converter circuit is a codec, responsive to codes from the microprocessor,
to supply a control voltage for controlling a local oscillator. From time to time
channel selection is automatically fine tuned.