Frequency synthesiser circuit for TV receiver - has memory system controlling variable frequency divider to select wanted frequency

摘要

The frequency synthesiser, is designed for use in a TV receiver. It has an oscillator whose frequency can be varied to accord with that of a given channel or type of receiver. The output of the oscillator circuit is frequency divided by a divider circuit whose denominator is selected according to the wanted frequency. The divider is controlled by a single memory. This memory may be subdivided into two parts or two entirely separate memories may be used.