- on Test & Measurement
- Published in issue 3/2014 on page 78
Hewlett Packard Model 200AB Audio Oscillator
The story of the Hewlett-Packard Corporation began back in 1939, when William Hewlett used a tungsten filament lamp in a vacuum tube Wien Bridge oscillator circuit. The light bulb provided the variable temperature coefficient resistance needed to keep the oscillator output voltage stable, while not adversely affecting the distortion. Hewlett partnered with David Packard to produce their first commercial product, the 200A Audio Oscillator.