This optically coupled circuit was found in the February 1968 Radio Electronics magazine. The circuit uses an LDR in modulation. Transistors are types of the time.
This differential amplifier, found in a 1964 Electronic Design, has a gain of 30. The setting can be...
This mid-waveband wireless microphone was found in a Raytheon transistor manual from the 1960s. The...
This circuit is based on the bistable configuration, but with the difference that the values of...