Hearing aid amplifier (CB22338E)

This amplifier uses germanium transistors of the time. The circuit is from a documentation from the 60's. The phone is high impedance magnetic.

60 Hz Pulse Generator (CB19534E)
In fact, this circuit can generate 50 Hz or 60 Hz signals depending on the power supply. The input...
Wien Bridge Oscillator (CB9041E)
Found in Motorola documentation from the 1970s, this circuit makes use of period components. The lamp is...
10 to 150 kHz Oscillator (CB6510E)
Found in an American documentation, this circuit may employ general purpose transistors and the...