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.
Bis This two-transistor circuit was found in the January 1994 issue of Electronics Now magazine. The...
This receiver for the police band, which at the time was 45 MHz, was found in a publication by...
This circuit is the digital indicator for the previous circuit and can be used with similar...