Good morning, What's the optimal oscillator topology for low phase noise (low frequency noise and phase noise floor) for 25Mhz/50Mhz/100Mhz frequency range.? Best regards, Rafal

I would say the 2 stage "Driscoll" oscillator is the way to go. I have had good luck with it up to 100 MHz. The first stage has the crystal in series with the emitter, but is otherwise a grounded emitter stage. The second stage is in cascode as a grounded base. The important operating condition is that only the second stage limits. First publications on it were in the early 1970's (search Michael Driscoll). Rick Karlquist N6RK On 2/6/2017 1:06 AM, Yeti Yetos wrote: > Good morning, > What's the optimal oscillator topology for low phase noise (low frequency > noise and phase noise floor) for 25Mhz/50Mhz/100Mhz frequency range.? > > Best regards, Rafal > _______________________________________________ > 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. > >

Hi One could easily spend years answering this sort of question. Several people on the list *have* done so. Two of them have already tossed up answers. What are you trying to do? What is your definition of “low”? How well equipped are you to test this sort of thing? How much tweaking are you willing to do? Do you have a source of (custom) low noise crystals? Lots of questions and lots of twists and turns in the answers as a result. Bob > On Feb 6, 2017, at 4:06 AM, Yeti Yetos <rtoporowski@gmail.com> wrote: > > Good morning, > What's the optimal oscillator topology for low phase noise (low frequency > noise and phase noise floor) for 25Mhz/50Mhz/100Mhz frequency range.? > > Best regards, Rafal > _______________________________________________ > 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.