[Test-Equipment] re: HP8640B audio oscillator thermistor

[J. Forster]

As I remember the first product was an audio oscillator. Many designs used a lamp bulb
as an AGC element. The Wein bridge puts out a very good sine with low parts count,

-John



DJED1 at aol.com wrote:

> Interesting about the wein bridge oscillator in the 8640.  This audio
> oscillator, if my memory is correct, was the first product developed by Hewlett  and
> Packard in their garage, and started what became the preeminent test
> equipment manufacturer.  It's interesting, but I guess not surprising, that  they
> would have carried the original circuit over into a signal generator.
> Ed