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.
This remote listening device was found in documentation from the 50's. The transistors used are...
Found in a 2005 Linear Technology application manual, this circuit provides outputs from a current...
Found in the September 1992 issue of Radio Electronics magazine. This circuit generates pulses that...