This circuit was obtained from Dutch documentation from 1964. The components are of the time, but current equivalents such as BC548 to BC108 can be used.
This circuit was found in an American publication from 1969. Transistors are from the time and can be...
We found this circuit in a 1998 documentation. The circuit makes use of CMOS logic and must be...
This 1 transistor circuit is from a Radio Electronics from December 1958… The circuit is battery...