This circuit was found in documentation for radio amateurs of the 1980s. This is the so-called roger-beep, which is the beep that is transmitted when the talk-listen function is changed.
Found in old documentation, this circuit has only the most difficult component to obtain the PUT....
This unijunction transistor circuit was found in Radio Electronics magazine from July 1968. The...
Found in a Popular Electronics from the 90s, this circuit is suitable for testing and tuning...