Found in a 1964 CQ magazine this circuit consists of an automatic telegraphic key, providing the correct duration for points and dashes. The circuit can be made with a current PNP transistor.
Found in a 1982 Maplin magazine, this circuit can be changed to work on other frequencies. The response...
We found this circuit in a 90s Popular Electronics. The circuit uses a pickup coil that consists...
This input circuit for an oscilloscope was found in Radio Electronics from the 90s. The operating...