This oscillator produces a modulated signal using a unijunction transistor. We found it in an American documentation from 1965. The circuit modulates in frequency the generated signal.
This amplifier was found in a Japanese publication in 1972. Transistors are uncommon today, and...
The current of this source is 200 mA at the most, and the output depends on the zener that may...
Found in Mallory documentation from 1968 this circuit uses an integrated circuit from that time. The...