We found this circuit in the Radio Electronics Handbook magazine special edition of 1992. The circuit uses an optocoupler as an electronic potentiometer.
We found this zener regulator in a 1978 radio amateur documentation. The operational can be...
This sensitive circuit was found in old documentation. The SCR can be any of the 106 series and...
This simple receiver was found in a book on transistors from 1954. The coil determines the...