Metal Detector (CB21929E)

This two-transistor metal finder was found in a Raytheon manual from the 1950s. The transistors are germanium from the time.

Astable Multivibrator (MSB016E)
This is the traditional configuration of na Astable Multivibrator using two NPN ttransistor....
Common Source HFET Amplifier (CB25569E)
This circuit, which combines a bipolar with any JFET, was found in the April 1993 issue of...
Operational Notch Filter (CB18978E)
This filter was found in a Texas Instruments manual based on an operational amplifier 741. Other...