Hi The fuzzy blob would appear to be an LM361 “high speed (20 ns)” comparator.
Surely it must have a jitter below a couple of nanoseconds :) Even that is only a guess since jitter is never mentioned in the spec sheet I dug up: http://www.ti.com/lit/ds/symlink/lm361.pdf Bob > On Apr 12, 2015, at 7:48 PM, Richard (Rick) Karlquist <rich...@karlquist.com> > wrote: > > > > 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. _______________________________________________ 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.
