Signal-seeking tuning system with automatic bandswitching for a television receiver

摘要: A signal-seeking tuning system for a television receiver scans the VHF and UHF signal bands until present TV channel is detected. Tuning voltage developed by digital-to-analog converter in response to binary word stored an up/down counter. The value of increases when scan-up applied decreases scan-down applied. Band signals are automatically sequenced next higher frequency band "rolls-over" from maximum minimum value, or lower rolls-over its value. Scanning stopped inhibiting changing valid sequence AFT Thereafter, compensated drifts incrementing decrementing whenever departs predetermined condition. This correction inhibited, however, at so that unwanted bandswitching avoided.