This circuit is from Delco Radio found in a 1968’s documentation. The transistors are of the time and are not given information about the driver transformer. Note the high supply voltage.
Found in American documentation from the 90s, this CMOS circuit detects the source of a signal and can...
I found this circuit in an old English magazine from 1981, but it can still be assembled with some...
This circuit was obtained from a 1969 Electronic Design. Transistors admit modern equivalents. The frequency...