Recording Low-Frequency Characteristic Curves

Abstract

The frequency dependence of four-terminal networks in low-frequency technology can be displayed by means of a suitably frequency-modulated signal. As the decay time of such circuit elements is considerable, a relatively slow rate of wobbulation must be used. As in HF investigations, each new frequency traverse should not take place until the voltage in the circuit elements has decayed sufficiently. It therefore seems suitable to carry out the frequency change manually and observe the filter characteristic of the object under study on a long-persistence fluorescent screen.