FM and VHF Transmitter (CB20572E)

Employing transistors of the time, this circuit was found in a documentation from 1963. The coils are according to the desired frequency range.

4 20mA Interface LTC1453 (CB4900E)
This circuit was found in a Linear Technology manual from the 1990s. The component is the LTC1453...
Simple Alarm with Reed Switch (CB3864E)
This circuit emits a sound when a magnetic field, of a magnet, for example, approaches the sensor....
Wien Bridge Oscillator (CB4690E)
This interesting sine wave oscillator circuit for the audio track uses an incandescent light bulb...