This old 1967 audio preamp uses germanium transistors. It was found in Japanese documentation at the time and has a gain of 70 dB, being powered by p V. The input sensitivity is only 12 mV.
The frequency of this circuit is determined by the 100 uF capacitors. These components can be...
This crystal-controlled 1000 kHz oscillator was found in 1980s American documentation. The...
This circuit was obtained from an American documentation from 1976. The circuit has a dynamic...