ELECTRONIC ALIGNMENT SYSTEM FOR A TELEVISION SIGNAL TUNER USING LOW-VOLTAGE VARACTOR DIODES TO PART OF CIRCUIT, AND INDEPENDENTLY CONTROLLING RADIO FREQUENCY TUNING CIRCUIT AND LOCAL OSCILLATING CIRCUIT

PURPOSE: An electronic alignment system for a television signal tuner is provided to use a DAC(Digital to Analog Converter) of low resolution while obtaining advantages of high resolution only in a necessary range. CONSTITUTION: A tuning equipment has an element(202) for receiving RF signals, an element for outputting signals, and RF signal processing elements(204,206) combined between the element for receiving RF signals and the element for outputting signals. The RF signal processing elements include a first circuit for processing RF signals and a second circuit for processing RF signals. The first and second circuits for processing RF signals have first and second elements for tuning the RF signals respectively. The tuning equipment includes a digital-to-analog converter(224) combined with the first element for tuning to generate a first control signal, and a phase locked loop(222) combined with the second element for tuning to generate a second control signal. A deviation range of the first control element is higher than a deviation range of the second control element.