It was a low-distortion audio oscillator used for testing sound equipment. It used the Wien bridge oscillator circuit, that had been the subject of Bill Hewlett 's masters thesis. It was also the first such commercial oscillator to use a simple light bulb as the temperature-dependent resistor in its feedback network. [2] .

Connect, protect, and deliver seamless experiences. The Model 200A was HP's first product. An audio oscillator is an instrument that generates one pure tone or frequency at a time. Through …

The oscillator section (tubes V1 and V2) is a resistance-tuned type cir- cuit. Basically, this oscillator is a two-stage resistance-coupled amplifier which is caused to oscillate by the use of a positive feedback network. This net- work is a frequency-selective resistance-capacity combination which controls the frequency of oscillation, By using a variable tuning capacitor for the capa- city ...

Like the other HP oscillators, the HP200A is a Wien bridge resistance-tuned audio oscillator using the light-bulb stabilized negative feedback circuit designed by William Hewlett while doing graduate work at Stanford.

2002年1月22日 · Today, the original prototype resistance-capacity oscillator Bill built as a graduate student resides in the HP Archives. At about the same time, Terman received a …

Hewlett-Packard's first product, 200A has a range of 20 Hz to 20 kHz and 200B can distribute 35 Hz to 35 kHz. General Radio before was the leader for RC-audio generators and other bench instruments.

Bill's prototype became the HP company's first product the HP 200A. As shown in the wiring diagram below, two options with different frequency ranges were available: the 200A and 200B. A small modification of 6 resistors values resulted in different frequency ranges 35 to 35,000 cps for the 200A and 20 to 20,000 cps for the 200B.

2015年6月20日 · 1943 HP 200A Audio Oscillator demonstration.Hewlett Packard's first test instrument.Story here:http://www.hp.com/hpinfo/abouthp/histnfacts/museum/earlyinstru...

2011年4月28日 · The unassuming -- if a little intimidating-looking -- metal box that you see here is the HP200A, an audio oscillator. That is, it generates one pure tone or frequency at a time. Through the years, HP oscillators were used to design, produce and maintain telephones, stereos, radios and other audio equipment.

The HP 200CD has the following specifications: Frequency coverage 5 cps to 600 Kc in 5 ranges. 160 mW into 600 ohms or 20 Volts open circuit at 1 % distortion and +/- 1 dB frequency response. The HP200CD remained in the Hewlett-Packard Test and Measurement catalog until 1985, a full 33 years which is rare in the electronics industry.