This circuit also appears elsewhere on this site, obtained from other sources. This is an 80's American schematic book. Instead the lamp can be used white high-brightness LEDs.
This circuit was found in a Texas Instruments handbook about operational amplifier. It has a very...
This circuit was found in a 1977 Radio Shack documentation. The circuit is tuned to 1.4 kHz, but...
This circuit was obtained from a 1980's QST magazine. The circuit can generate 1 to 15 MHz signals...