This interesting circuit uses a sodion valve that we have already described in an article on the website. The circuit uses several batteries for power. The phone is of high impedance.
The circuit shown was found in an American documentation from 1964. The circuit uses transistors of...
We found this antenna amplifier or Booster circuit in an Electronics Now from the 90s. The circuit...
This dimmer with a unijunction transistor and SCR appeared in Radio Electronics magazine in March...