Metal Detector (CB21929E)

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

TDA2006 8W Single Source Amplifier (CB15823E)
This amplifier must be supplied with a voltage of 24 V and the resting current is of the order of 4...
Photo multiplier tube source (CB8121E)
This circuit is from a magazine 73 for radio amateurs of the 90s. The circuit generates the high...
Quadrature Oscillator (CB19016E)
This circuit generates quadrature signals in frequency that depend on the 18 pF capacitors. These...