HP Hewlett Packard Audio Oscillator 200B - Vintage WWII Unit No Power AS IS

Rare, Vintage 1939, WWII Navy & Silicon Valley History…

HP Hewlett Packard

Audio Oscillator

Model 200B

Some history:

David Packard and Bill Hewlett founded their company Hewlett-Packard in a Palo Alto, California garage, known historically as the birthplace of Silicon Valley. Their first product, the HP 200A Audio Oscillator, based on Hewlett’s masters thesis, rapidly became a popular piece of test equipment for engineers.

In 1939, when the sound engineer for the movie Fantasia from the Walt Disney Studios saw the Model 200A audio oscillator in action, he asked Bill Hewlett to make some modifications to it, and the Model 200B was born. Disney ordered eight of the Model 200B at $71.50 each, becoming an early customer of HP.

Disney engineers used HP 200B oscillators to test the various channels, recording equipment and speaker systems in the 12 specially equipped theaters that showed Fantasia in 1940.

This particular 200B was produced for the Naval Research Laboratories during World War II.

Behind the Creation of HP200A & Birthplace of Silicon Valley:

In 1939, Hewlett completed his EE masters thesis at Stanford. His thesis project was a variation of the Wien bridge oscillator, in which he used the negative differential resistance of an incandescent lamp to act as a parasitic impedance in the feedback loop. This ensured that the oscillator operated just at unity gain, and thus produced steady, low-distortion output. This was a really clever and elegant hack — many oscillators of the time did not produce steady oscillations, but instead fed a pulse stream (sometimes just a rectified mains signal) to an RLC tank circuit with a large Q — so the output was a series of decaying oscillation patterns with modulation at this pulse frequency. Oscillators which did produce steady output were large and expensive. Hewlett replaced the complex control systems of these with a simple light bulb. HP's first product, the HP200A bench oscillator, was based on Hewlett's thesis design, optimized for manufacturing in the now famous garage in Silicon Valley.

Measures 15” wide x 9” deep x 7” tall.

CONDITION:

Not powering on, sold as is for display or repair. See photos for details.

Please message for any questions, thanks.