This circuit was found in a 80s American documentation. The zener diodes determine the points of action of each stage and the transistors can be general purpose types.
Found in a Popular Electronics from the 90s, this game can be seen in other configurations on this site. The...
This single-channel remote control transmitter operating in the FM range uses common components and...
Although it is a common configuration today, this circuit was taken from an old publication. The...