Hi Digital pots have *lots* of issues. A high quality wire wound pot likely will be significantly more stable and lower noise than your typical digital unit. In addition the 10 or 20 turn wire wound will have far more “steps” than a digital pot.
One advantage that a digital pot has is small size. If you want to ovenize a pot to improve it’s temperature performance, that’s a good thing. Indeed a lot of modern oscillators have digital pots in them to set this or that during the production process. ==== If you apply a 1 ns rise time step to the EFC of an oscillator it will not change frequency in a nanosecond. The tune port has a bandwidth. On an OCXO that bandwidth might be in the 10’s of Hz range. If you have bypass caps all over the place (and some large resistance here and there) on your EFC then indeed the caps can have various issues (leakage changes, dielectric absorption …) that can take a while to settle out. Is that minutes or days? It very much depends on just what you have wired up. So as usual, no simple answer, only a lot more questions. Bob > On Jan 27, 2020, at 1:53 AM, Perry Sandeen via time-nuts > <[email protected]> wrote: > > Yo Bubba Dudes!, > Previous posts mentioned wiper noise and stability of a mechanical pots after > tweaking. > My questions are: > Do digital pots after setting have wiper noise? > When making fine tuning tweaks to the EFC of an OCXO, can one move it to its > *dead on* setting right away or is there some lag that must be considered > requiring to do it in steps? > Regards, > Perrier > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
