This simple Morse Code oscillator was found in a 1980s American documentation. The power supply should be powered with 5V and the integrated can be the 7400.
This version of the Pierce oscillator with the 2N3904 was found in the January 1994 issue of...
The traditional configuration of a non-inverting amplifier with the operational 741 shown in the...
This circuit is from a Radio Electronics from January 1958. The transistor is the CK722, and the...