Hans, would mixing your 125KHz with a 2.5MHz or 5MHz low noise reference to get it into a range that the analyzer can read work? You could use a system like the Miles timepod phase noise analyzer, a mixer, a 5MHz low-noise reference, and a low-pass filter to make use of the >500KHz lower range of the timepod. You could divide your 5MHz reference by 2 to get 2.5MHz +/-125KHz, with a 2.5MHz carrier being easier to filter out one of the two side-bands with a high/low-pass or notch filter? Maybe the FSUP itself could be used to remove one of the sidebands and the 2,5MHz carrier, and analyzer the remaining side-band? bye, Said In a message dated 12/5/2012 13:27:28 Pacific Standard Time, [email protected] writes:
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.
