HI The circuit they show is not very low phase noise, so adding stuff is not going to degrade it much. It will lower Q, but again, it’s not really Q limited over most of the range.
The real issue with the circuit is that it has lousy load isolation. Bob On Apr 23, 2014, at 9:06 PM, Tom Knox <act...@hotmail.com> wrote: > Does adding these filter elements lower Q or affect Phase Noise? > Thanks; > > Thomas Knox > > > >> From: li...@rtty.us >> Date: Wed, 23 Apr 2014 17:47:26 -0400 >> To: time-nuts@febo.com >> Subject: Re: [time-nuts] Wenzel oscillator - L1 value? >> >> Hi >> >> Roughly (very roughly) speaking, the series combination of C1, C2, C3 and L1 >> should equal the load capacitance of the crystal. If there is a varicap, >> it’s likely in series as well. If the crystal is cut for series, then L1 >> resonates with the caps in series. >> >> You can put it on a Spice program and get more accurate results. >> >> Bob >> >> On Apr 23, 2014, at 10:23 AM, li...@philpem.me.uk wrote: >> >>> Hi, >>> I'm currently playing around with crystal oscillators (specifically a >>> homebrew OCXO) and came across the Wenzel low-distortion crystal oscillator: >>> http://www.wenzel.com/pdffiles1/pdfs/xtalosc.pdf >>> >>> This uses an inductor (L1) to trim the crystal frequency, with the note >>> that a varactor/varicap could be added to allow the frequency to be trimmed >>> electronically. >>> >>> Has anyone built one of these oscillators? >>> >>> How would you pick a value for L1? I've been reading up on other crystal >>> oscillator types (Colpitts, Clapp,...) and have yet to find anything which >>> uses this style of frequency trimming. >>> >>> Where would I add the varactor if I wanted to add EFC? Across C3? >>> >>> Thanks. >>> -- >>> Phil. >>> phil...@philpem.me.uk >>> http://www.philpem.me.uk/ >>> _______________________________________________ >>> 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. > > _______________________________________________ > 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.
