abstimmschaltung receiver especially for television receivers

摘要

The circuit includes a local oscillator which is formed from an amplifier which is coupled to an LC resonator circuit. The first stage is a differential pair of NPN transistors (T1,T2). The second stage is another pair of NPN transistors (T3,T4), with their emitters connected together to the collector of one of the first transistors. One transistor (T3) of the second pair has the main load resistance (RL) in its collector circuit while the base is returned to the collector of the other transistor (T1) of the first pair, with supplementary load resistance (Rb).