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.
This circuit makes use of a special LM195 power transistor not very easy to obtain. The circuit is from...
Found in documentation from the 90s, this circuit can employ other comparators in the series such as...
Suggested by Philips in a 1970 publication, this circuit uses components from that time. No...