Voltage divider with selectable characteristics for diode tuning - having potentiometer section between beginning and wiper shunted by resistor

摘要

The divider is intended specially for broadcast receivers, and consists of a linear potentiometer. In order to obtain a nearly linear frequency scale, the required division characteristic for generation of the diode control voltage (UR) for eg. the f.m range is achieved by connection of a shunt resistor to the resistance track between beginning (A) and wiper (S). The potentiometer (P1) is in series with a fixed resistor (R1) and two variable resistors (P10, P12). The wiper line (S) is also shunted by a fixed resistor (R2) and another variable resistor (P11).