This amplifier was found in a 1957 Rayrtheon documentation. The circuit can be fitted with a BC558 transistor. Driver and output transformers can be obtained from unused transistor radios.
This circuit was obtained in a 1975 documentation. The maximum frequency depends on the diodes and the...
In the figure we have the basic configuration of an operational amplifier for AC signals using the...
This traditional signal injector from a 1970s publication uses germanium transistors. We can mount it...