Re: Low distortion sine wave VCO's - state of the art?

Winfield Hill wrote:
Tim Shoppa wrote...
(snip)
Since my frequency range is so narrow, is a 8038 or XR-2206 followed
by many poles of low-pass filtering out of the question?


Yes, by all means, add a sharp low-distortion filter. Problem solved.


Does an 8038 0r XR-2206 have a low enough phase jitter to produce a ..01% pure frequency, even with reasonable filtering?

The kind of oscillator that came to my mind is the sine cosine oscillator made with two integrators in a loop. But there are still two resistors that have to change in tandem to swing the frequency. But the automatic gain control will compensate for some mismatch, if the frequency changes slowly enough. Or is there a variation that allows the frequency to be changed with only one resistor?

http://www.interq.or.jp/japan/se-inoue/e_ckt20.htm

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