This simple 1-transistor audio preamplifier appeared in the June 1968 Radio Electronics magazine. The transistor is a general-purpose type of the time. The gain is 14 dB.
This 4.5 MHz oscillator, or according to the crystal, was found in American documentation from the...
This interesting circuit for testing signal transistors with the oscilloscope was found in the...
This is a different circuit for a component from the past, the zirconium arc lamp used in...