On 4/12/2015 2:22 PM, Magnus Danielson wrote:
Hi, The buffer transistors has not AC-bypass of the emitter resistance, so that the DC current becomes large and thus contributes flicker noise. The comparator at the bottom isn't doing a beutifull work of squaring things up without contributing noise, considering the sine output of the 10811. Was that it, Rick? Cheers, Magnus
The resolution of page 13 is poor, and it seems to be a bitmap instead of a vector file. The fuzzy thing in the lower right corner looks like it might be a comparator. I think this was the smoking gun. There was a saying by H.L. Menken to the effect that for every complex problem, there is a simple, obvious, invalid solution. Squaring up a 10811 with a comparator is a perfect example of this principle. Non-time-nuts always seem to gravitate to this design. Of course you're right, any comparator will add jitter to a 10811. The faster they are, the more jitter they add. I noticed that the standard 10 MHz oscillator is built with an ECL line receiver. Another example of Menken's saying. This is a TERRIBLE oscillator design, but one that would appeal to the non-initiated. I built one of these oscillators in 1976 at the suggestion of my boss. After seeing how bad it was, I quietly designed it out and never used it again. Rick Karlquist N6RK _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
