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Ham op:
Absolutely! Any amp is an oscillator, any oscillator is an amp... just depends on how ya use it (mainly feedback.) There is also the subjects of "thermal noise" and "quantum noise", both contribute to the ease which with a circuit begins and sustains oscillations... Well, unless the laws of physics have changed! John "Ham op" wrote in message news John, I'm very serious when I say that 'white noise' is critical to Colpitts/Hartley oscillator operation. The feedback equation for oscillation requires a voltagecurrent gain greater than 1 and a phase shift of 180 degrees [in simplified terms]. Starting conditions, in the absence of white noise, has zero input voltage and hence zero output voltage and therefore no oscillation! The presence of white noise provides the starting conditions, the Vin to be amplified, and the tuned circuit, L and C, provides the frequency discrimination, and the fundamental frequency of the oscillator. The Capacitive voltage divider [Colpitts] or the Inductive voltage divider [Hartley] provides the feedback factor. The active device, tube, transistor, FET, etc. provides the gain and contributes to the phase shift. White noise, frequency selectivity, gain greater than 1, and 180 degrees phase shift are absolute requirements for an oscillator. In the absence of any one there is NO oscillator. The white noise provides the starting conditions for oscillation!!! John Smith wrote: Hmmm... No, I don't believe I will have to read anything... But, if you can't tell the difference between a white noise generator and an osc giving a clean fundamental signal with greatly suppressed/filtered harmonics (or even, non-existent harmonics), you may wish to read-up before taking that project to the air... John |
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