Receiver tuner permitting channel searching

摘要

The TV tuner has an oscillator whose frequency is controlled by a binary number N applied to a control loop from a processing circuit to which coded data are applied. The control loop has frequency dividers delivering a first signal which is a function of the number N. The first signal is compared with a reference signal for delivering a third signal used for tuning.Digital data allocated to the channels is stored. Devices automatically or by hand scan the store step-by-step. Signal generators are used to derive the number N from the stored data. The processing circuit generates a first series of N numbers depending on a first coded input signal, the numbers corresponding to all receivable according to a given standard channels. It is switched forward by one step on reception of a second coded input signal