HI > On May 20, 2015, at 11:55 AM, Richard (Rick) Karlquist > <rich...@karlquist.com> wrote: > >> >> The only gates that seem to do very well are high speed (as in 74AC or >> faster) >> silicon CMOS. You need to run them with a fairly clean supply and feed them >> with a p-p input that matches the supply voltage. Other than that, not a lot >> of magic. Are they ideal - surely not. Will they hit 2x10^-13 ADEV at 1 >> second and >> drop from there as tau increases - yes they will. >> >> Bob >> > > Interesting. Back in the stone age in 1990, 74AC was state of the art. > As soon as it came out, I used it exclusively for everything that didn't > require ECL, for which I used ECLinPS exclusively. > > In the 5071A, we used one to square up 80 MHz for the DDS board. You > are exactly right: put in a huge sinewave obtained by good old > fashioned analog anplifiers and let the 74AC do its thing.
… you actually can do a pretty good job with just a terminated L network feeding the input to the gate. It’s a high input impedance so driving it from 200 to 1K ohms isn’t all that different than 50 ohms. Again - not ideal, but it saves a few parts and some current. Bob > 80 MHz > is pretty much flat out for a 74AC series. The 80 MHz came from a > 10 to 80 MHz multiplier running from the 10811. > > 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.