The purpose of this circuit is to measure the resistance of an antenna at the resonant frequency. The circuit is from an old American documentation for hams.
This circuit uses a complementary unijunction transistor that is not the common type. The...
This adjustable source was found in a 1979 documentation, but all components are still common...
The basic circuit of a flip-flop for use as a frequency divider or one-bit memory is shown here....