Thanks again. I have some MCL T1-6T transformers sitting here so maybe they will work.
Regards, Jerry > On Dec 19, 2018, at 12:03 PM, Bruce Griffiths <[email protected]> > wrote: > > NIST used off the shelf RF transformers in their mixers based on diode > connected (collector connected directly to base) 2N2222. The transformer > impedance ratios (!:5 IIRC) are specified in the papers on the mixer > performance. > Suitable transformers are made by Minicircuits and others. > > Bruce > >> On 20 December 2018 at 07:04 Jerry Hancock <[email protected]> wrote: >> >> >> Thanks to all that replied, lots of good info which will take me months to >> sort through, especially the link to Jürg Kögel looks helpful as well as a >> note from Bert. >> >> Attila, Yes, more phase noise than long term though this is really an >> exercise to get a better understanding of oscillators and measurement >> techniques. >> >> The 2n2222 mixer sounds like another H-mode, I’ll have to look at it. It >> probably uses self-wound, micro-sized bobbins which will be a challenge for >> me :-]. >> >> Bob, I think you were the person who pointed me to the loose PLL a while >> back. The circuit I am building used a gain of 300ish (30k/100) and I >> expect that to really clip when unlocked. I have a 10-turn variable in the >> circuit to bring it close initially. >> >> Another question or if you can point me to the method, if you are using >> quadrature signals, is the measurement then the geometric sum? Or do you mix >> them back together? I am using a 3457a on the PD after an amp right now and >> I would think you would need either another meter, which I have, or a >> scanner, again I have both. >> >> My N2PK VNA uses two 24bit, low noise ADCs (LTC2410) for the same purpose >> more or less. It has effectively two DC receivers with two DDS. I can throw >> away the DDS and mixers and just read the DC voltage. I have a second N2PK >> board I never finished as I planned to use another master oscillator on it >> with lower PN, but I needed a couple of parts and my tremor made SMD >> soldering difficult. This was one of the drivers for my interest in phase >> noise. Now that I think about it, I can repurpose the second board, >> bypassing the MC1496 mixers. They are filtered to be close to DC within a >> few hz and has -135dB noise floor. I can even change the input filter to >> use the 220 ohm/.0046uf R/C recommended. >> >> I wish there was a way to use or modify one of my 8568B Spectrum analyzers >> to do this. >> >> Regards, >> >> Jerry >> >> >>> On Dec 19, 2018, at 7:57 AM, Attila Kinali <[email protected]> wrote: >>> >>> Hoi Jerry, >>> >>> On Tue, 18 Dec 2018 23:18:42 -0800 >>> jerry <[email protected]> wrote: >>> >>>> I'm playing around with various methods of collecting data for >>>> oscillator testing and would like to try the loose PLL which >>>> requires a phase detector (PD). >>> >>> I guess you are looking more into phase noise than stability? >>> >>>> I'm testing an AD8302 but that has a flat spot around 176 to 180 degrees. >>> >>> All phase detectors exhibit non-linearity in some form or other. >>> If you get all the way to +/-176° with good linearity, then be >>> happy. If you need more than that, then you have to either use >>> two phase detectors that are driven with a reference that is 90° >>> apart, or you have to digitize the signal and do the same in digital. >>> >>>> One of the papers I read recommended the subject PD but it is out of >>>> stock everywhere, including the subs. One Minicircuits PD is in stock but >>>> pricey. I can try a double balanced mixer like the SBL or TUF series >>>> (which >>>> I have on hand) but I thought maybe someone on the list has the subject PD >>>> they dont need. If so, please send me a note. >>> >>> There is a decent alternative: Use two transformers and 4 2N2222 to >>> do your own mixer. The quality of it, according to NIST[1] is pretty >>> good. I assume that any other NPN transistor of similar make-up will >>> also do and lead to same/similar performance. >>> >>> You might also want to have a look at Enrico's Mixer Tutorial[2] >>> >>>> I'm slowly gathering parts for Riley's small Dual Mixer Time Difference >>>> test kit but it will take some time which I'm unfortunately running out >>>> of due to mild Parkinsons getting in the way of SMD soldering. I've used >>>> my HP 5371a in the past but it sounds like a jet engine. I recently >>>> ordered a TICC as well. By the time I'm done I probably will have >>>> purchased more than a commercial product, ha! >>> >>> Jürg Kögel did a redesign of the Riley DMTD earlier this year, >>> which looks very nice. And the measurements I've seen are very >>> impressive (it's on par with the best state of the art I am aware of). >>> So you might want to contact him and see whether he has some board left. >>> >>> Attila Kinali >>> >>> >>> [1] "Residual PM Noise Evaluation of Radio Frequecny Mixers" >>> by Barnes, Hati, Nelson, Howe, 2011 >>> https://doi.org/10.1109/FCS.2011.5977868 >>> http://time.kinali.ch/mixers/residual_pm_noise_evaluation_of_radio_frequency_mixers-2011-barnes_hati_nelson_howe-05977868.pdf >>> >>> [2] "Tutorial on the double-balanced mixer" >>> by Enrico Rubiola, 2006 >>> http://arxiv.org/abs/physics/0608211 >>> -- >>> It is upon moral qualities that a society is ultimately founded. All >>> the prosperity and technological sophistication in the world is of no >>> use without that foundation. >>> -- Miss Matheson, The Diamond Age, Neal Stephenson >>> >>> _______________________________________________ >>> 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. >> >> _______________________________________________ >> 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. > > _______________________________________________ > 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. _______________________________________________ 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.
