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.
In the figure we have the way to use a shift register to divide the frequency of a signal by 9....
This circuit was found in an English publication from 1989. The integrated circuit is an...
With the used coils and the power transistor this circuit amplifies the 5 W of a 11-meter...