Found in a 1970 American publication, this circuit uses transistors of the time. These transistors may be replaced by current equivalents. The factor Q is greater than 3 000.
The integrated circuit used in this 1987 project is not very common these days. However, if found...
This 1-transistor reflex receiver was found in a 1963 publication. The coil is for the mid wave...
This circuit uses a complementary unijunction transistor that is not the common type. The...