Model 200AB Audio Oscillator, 1952
An audio oscillator is an instrument that 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 Model 200AB and its sister instrument, the Model 200CD, were introduced at the same time in 1952. These new oscillators represented a substantial increase in versatility over previous ones. For example, the frequency range of the 200AB (20 cps to 40 kc) was such that it replaced two of the older HP oscillators, Models 200A and 200B, which were discontinued. This was accomplished without an increase in price.
In addition to advances in electrical design, the cabinetry of the new oscillator was redesigned. The cabinet width was reduced to save bench space, while the appearance was designed to be more pleasing and to aid in operation. One of the improvements was a large, 6-inch tuning dial.
The 200AB was used for amplifier testing, as a bridge voltage source, for testing transmitter modulator response, modulating signal generators, syncing pulse generators, making loudspeaker resonance tests and powering mechanical systems.