The indicated circuit uses an unusual buffer from National Semiconductor. The frequency is given by resistors R1 and R2 as well as capacitors C1 and C2.
This circuit is from a Radio Electronics from April 1972. The circuit uses power transistors of...
We found this simple circuit in a 1999 documentation. It converts low-intensity sinusoidal signals (a...
This very high voltage circuit was found in the 1990 special issue of Radio Electronics...