Found in RCA documentation from the 90s, this circuit uses components from that time. CA3019 is uncommon today and can be replaced by discrete diodes.
I found this circuit in an old Argentine publication from 1973. The components are no longer...
This circuit has an LED indication of the timing progress, having been found in an old...
This simple signal tracer was found in a Popular Electronics from the 90's. The transistor can be a...