This amplifier with old germanium transistors is from a 1957 documentation. The power is a few hundred milliwatts and the transformers are common types of driver and output of the time.
Measuring capacitances and resistance this simple instrument was found in Radio Electronics...
This circuit generates noise pulses for audio equipment probes. The circuit is from a 90’s 303...
This protection circuit was found in a 1987 documentation. It consists of a relay that is...