Broadcast receiver with capacitance diode tuning - has circuit for stabilised tuning voltage generation esp. for a car receiver

摘要

Receiver supply voltage is applied to a stabilising circuit for the tuning voltage generation. It has a control transistor controlled through an amplifier stage connected to a reference voltage source, by a part of the stabilised voltage and by a control supplied by a frequency discriminator. The amplifier stage for the stabilising circuit is a differential amplifier whose first control input (S1) is connected through a resistor (R6) to the reference voltage source, and its second input (S2) through a further resistor (R3) to the tapping of a voltage divider (R4, R5) connected to the stabilised tuning voltage. The frequency discriminator two terminals are connected to the control inputs (S1, S2).