Other amplifiers of the series like the MC3301, MC3401 and LM2900 can be used in this circuit. We found this setting on Motorola's Linear Interface ICs. The circuit uses a magnetic sensor.
This low frequency doubler requires a 50 mV signal at the input. The circuit is from an old...
This oscillator generates a 1 kHz signal, using an old germanium PNP transistor. The circuit was...
Found in an Elektor from the 90s, this circuit is suitable for viewing audio signals on an...