Hi Poul-Henning, On 2020-08-04 00:32, Poul-Henning Kamp wrote: > -------- > Attila Kinali writes: > >>> The main reason I dont just repair/replace the A15 is that >>> I want to find out how much instability the PSU contributes. >> There are very few points where supply voltage (in)stability >> contributes to long term frequency drift in a Rb vapor cell standard. > Obviously. > > But it does contribute quite a lot on the sub-hour time-scale, some > of it via temperature-dependencies.
If that is the range you aim to improve, then I strongly recommend you do re-read the postings I did about phase noise in detector range, as I have showed that phase-noise get's mixed down to DC and increase the noise there. With very ugly and hand-wavey hack I was able to significantly reduce that noise essentially by cleaning up the phase-noise. Just as Corby's filter trick, which also aims to reduce noise, one need to figure out the dominant noise sources, then reduce them from the top candidate and then down. I have not seen your efforts include the oscillator phase-noise consideration. With that I'm not saying that you attempts is wrong, rather, maybe not the first thing that I would start with. I will pursue my phase-noise approach until I see diminishing returns there, and then look to see what could be the next dominant noise contribution. In this regard I do not see Corbys or your approaches as lost, but rather very interesting, as I come to that point. > > I would go for the LTZ1000 if you can. The LM399 has gone out of >> fashion for a reason: [...] > Yes, I know, being also a volt-nut :-) I have not yet jumped down that rabbit-hole as I am by far not done with the current one. :) I've been looking at the LTZ1000 and one day I may get some. Cheers, Magnus _______________________________________________ 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.
