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 Motorola documentation from the 1980s, this circuit employs an integrated device from...
This input circuit for an oscilloscope was found in Radio Electronics from the 90s. The operating...
This circuit was found in Motorola documentation from 1968, using high power transistors and...