On Thu, 21 Jul 2016 18:47:24 -0700, you wrote: >On 7/21/2016 4:56 PM, Nick Sayer via time-nuts wrote: > >> Oh my. Thats a bit more than I was originally considering What I had in >> mind was adding a DAC front end to an OCXO so that you could tune the EFC >> with serial commands rather than analog and calling that a product. >> > >20 years ago when HP was working on a so called "smart clock" >GPS box, they decided to do what you said, use a DAC to >tune the EFC on the E1938A oscillator. I >recommended to them NOT to try to do that, but they >didn't listen to me. At that time, it >was nearly impossible to come up with a DAC, buffer >amplifier, and voltage reference that didn't degrade >the stability of the E1938A, which isn't even as stable >as a 10811. What you need to ask yourself is: in >2016, can I finally get analog components that are >an order of magnitude or two better than what was >available in 1996? I don't know, without researching >it. Certainly, we can't depend on Moore's law coming >to the rescue. If anything, that works against analog >IC's by obsoleting older analog processes. > >Also in 1996, phase microsteppers were already legacy >technology and didn't have a good reputation for spectral >purity. Another non-panacea. > >Rick
Increased integration has only helped insofar as you can attempt designs which would have been prohibitive before. I keep trying to come up with a charge balancing design but what about Linear Technology's solution from back in 2001? A Standards Lab Grade 20-Bit DAC with 0.1ppm/°C Drift http://www.linear.com/docs/4177 _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
