Sequential channel tuning system with a memory

摘要: An all-channel two mode television tuning system includes a presettable counter for deriving the number of receivable channel by counting local oscillator frequency. The frequency is varied ramp voltage circuit under control comparator which adjusts based upon difference between derived and desired sequentially generated externally activated counters. A 82 × 1 bit read/write memory addressed in first or program to provide locations storage signals preselected channels. In second operate logic circuitry interrupts advancement counters whenever corresponds number.