01-10-2014, 11:34 PM
That's a really interesting oscillator, and very well built as is typical of WE equipment. Looks like its a beat frequency audio generator where two RF carriers are mixed together to produce an audio signal.
Nice thing is that it can generate an audio sweep from 100 Hz to 15 KHz with one turn of the knob. Great for a quick check of audio freq response. Downside is that they are a bit unstable because you are subtracting two RF signals from each other, magnifying any freq drift. The waveshape may also not be a very good sine wave because of harmonics in the RF signals and nonlinearities in the mixing process.
The HP 200CD is a true Wein Bridge oscillator and produces a very nice low didtortion sine wave. Its probably more suitable for critical testing, and of course its a classic HP design.
Nice thing is that it can generate an audio sweep from 100 Hz to 15 KHz with one turn of the knob. Great for a quick check of audio freq response. Downside is that they are a bit unstable because you are subtracting two RF signals from each other, magnifying any freq drift. The waveshape may also not be a very good sine wave because of harmonics in the RF signals and nonlinearities in the mixing process.
The HP 200CD is a true Wein Bridge oscillator and produces a very nice low didtortion sine wave. Its probably more suitable for critical testing, and of course its a classic HP design.
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