Abstract: The circuitry is used, for identifying television transmitters, in a television set receiving synchronizing signals and line flyback pulses characteristic of television transmitters, particularly for television receivers including a station finder circuit. The circuitry, during the time period of the line flyback pulses, derives samples of those signals appearing above the black level of the video signal, from the demodulated input signal. The number of amplitude jumps determined during the time period of the line flyback pulses is utilized as the criterion for identification of a television transmitter. The signals appearing above the black level of the video signal are inverted and then combined, in an AND circuit, with the line flyback pulses, and the output of the AND circuit is connected to a digital counter circuit to supply the output pulses thereto as counting pulses, with the flyback pulses being supplied to the digital counter circuit as gate pulses.

Abstract: A tuning circuit for tuning a high frequency receiving apparatus with residual sideband modulation, especially a television receiver, with a counter for forming encoded values of tuning voltage, with a store for the digital storing of the encoded values of tuning voltage, with a D/A converter for generating the analog tuning voltages from the encoded values and with a circuit for automatic fine tuning to the required position of a received transmitter. In such tuning circuit means are provided which so alter the value of the tuning voltage before or during writing into the store or after or during reading out from the store that this value corresponds not to the required tuning position but to a tuning position shifted into the fully transmitted sideband. The exact tuning ot the transmitter to the required position is effected by the circuit for fine tuning.