Hi A "3048" style measurement with the carrier suppressed by lock should do pretty well. If the XOR's are out, there are a lot of mixers available that work at 125 KHz. A simple op-amp buffer and a sound card could do what you need to do.
Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Adrian Sent: Wednesday, December 05, 2012 4:33 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Very challenging phase noise measurement, does anyone have an idea?? For phase noise the frequency range is 1MHz to 8/26.5/50GHz The spectrum analyzer works from 20Hz to max. Adrian Azelio Boriani schrieb: > Isn't the FSUP a 110K euros equipment 20Hz-50GHz capable? 125KHz shouldn't > be a problem. I had an FSUP for 25 seconds to play with... really > impressive but too limited test time to appreciate fully. > > On Wed, Dec 5, 2012 at 1:14 PM, Bob Camp <[email protected]> wrote: > >> Hi >> >> Just about any of the high speed CMOS parts should work. A 74AC86 is about >> the earliest part I would trust. Any of the fast logic families that came >> after that should do equally well. >> >> Bob >> >> On Dec 5, 2012, at 7:03 AM, Hans Rosenberg <[email protected]> wrote: >> >>> Hello Time-nuts, >>> >>> I have to do a phase noise measurement and I'm wondering if anyone here >> has any ideas on that. We have to measure the phase noise of a 125kHz >> carrier (5Vp-p signal level). The measurement system should have a noise >> floor that is -164dBc/Hz at a distance of 1kHz to 8kHz away from the >> carrier. >>> Our current plan is to use 2 of these sources, have one in free running >> mode and lock the other one to the first one using an XOR gate and then use >> the output of the XOR gate as an output signal. However, we are wondering >> if any of you know a better idea. Maybe there is an off-the-shelf piece of >> equipment that can do that that we could rent. Or maybe we could increase >> the frequency to a few megahertz using a pll, which means the signal comes >> into the measurement range of our FSUP phase-noise analyzer. Problem is, >> the phase detector would then need to have an insanely low noise-floor (in >> our idea the XOR also has to have this insanely low noise floor as well off >> course) so does anyone have experience with anything like this? Does anyone >> know an XOR with these good specs? I don't have a clue what a standard >> 74lvc1g86 would do. Needless to say the supply of this XOR would have to be >> ridiculously clean, but I do have a solution for that problem. >>> Any help is greatly appreciated! >>> >>> Best regards, >>> >>> Hans Rosenberg >>> _______________________________________________ >>> 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. >> >> _______________________________________________ >> 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. >> > _______________________________________________ > 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. > _______________________________________________ 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. _______________________________________________ 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.
