Bruce, fine, I will do what possible, but not this night anymore, it is very late already (early morning) ! Would be of high interest what others are experiencing.
Thanks a lot, Arnold On Mon, 20 Apr 2009 10:59:10 +1200, Bruce Griffiths wrote: >Arnold >They do have lower isolation than the phase detectors and the TUF mixers. >However it would be well worthwhile measuring their dc offset, its drift >and their phase noise. >Its possible to mitigate the effects of lower isolation by using low >phase noise isolation amplifiers. >If you do this please make it available so that it can be used by others >in making similar decisions. >It would be useful if anyone else who can measure the phase noise of any >mixers they have do so. >In this way we can build up information on the phase noise performance >of various mixers without having to purchase mixers for such measurements. >Bruce >Arnold Tibus wrote: >> Bruce, >> >> Are such as >> SRA-1H or SRA-3H no possible candidates? >> Such I have still somewhere in a drawer. >> >> Arnold >> >> On Mon, 20 Apr 2009 10:25:28 +1200, Bruce Griffiths wrote: >> >> >>> Arnold >>> >> >> >>> Some of the early equipment produced by NIST used mixers from a company >>> that eventually became into Minicirucits. >>> >> >> >>> Suitable candidates from the Minicircuits range are: >>> >> >> >>> TUF-1H+: >>> http://www.minicircuits.com/pdfs/TUF-1H+.pdf >>> >> >> >>> This mixer doesnt have isolated RF, LO and IF grounds so external >>> transformers would be rrequired. >>> It does have somewhat higher port to port isolation than most mixers. >>> >> >> >>> The minicircuits phase detectors such as: >>> >> >> >>> http://www.minicircuits.com/pdfs/RPD-1+.pdf >>> >> >> >>> http://www.minicircuits.com/pdfs/MPD-1+.pdf >>> >> >> >>> are worth considering, at least they have separate RF and IF grounds, a >>> high maximum output as well as low dc offset and offset drift. >>> >> >> >> >>> All of these are below $US25 (at the source). >>> >> >> >>> The phase detectors are perhaps the safest option however measurement of >>> their phase noise would be advisable. >>> >> >> >>> Bruce >>> >> >> >>> Arnold Tibus wrote: >>> >>>> On Mon, 20 Apr 2009 09:03:36 +1200, Bruce Griffiths wrote: >>>> >>>> >>>> >>>>> Corby Dawson wrote: >>>>> >>>>> >>>>>> Arnold, >>>>>> >>>>>> Look at the top of page 3 on the link below. Not sure how they arrived at >>>>>> their conclusion but there is one opinion on the HP mixers! >>>>>> >>>>>> http://www.unusualresearch.com/AppNotes/TimeNuts/OptDualMixer.pdf >>>>>> >>>>>> Corby Dawson >>>>>> ____________________________________________________________ >>>>>> Debt collectors calling your house? Click here to consolidate into one >>>>>> payment. >>>>>> http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTIk3l9oQnolYGEY40TVwmsBD4opDDeVSRG36KHWHhZWexSiuRrXdm/ >>>>>> >>>>>> _______________________________________________ >>>>>> 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. >>>>>> >>>>>> >>>>>> >>>>>> >>>>> Statements about the low flicker noise of these mixers are sprinkled >>>>> throughout the phase noise literature. >>>>> Someone must have measured the phase noise of these and other mixers at >>>>> some time. >>>>> >>>>> >>>> >>>> >>>>> Its relatively easy to measure mixer phase noise: >>>>> All one needs is a low noise preamp plus a sound card a 90 degree hybrid >>>>> (or a suitable length of coax and a splitter) and a low noise source. >>>>> >>>>> >>>> >>>> >>>>> However NIST papers often include a phase noise plot (attached) that >>>>> illustrates that high level mixers can have a significantly lower phase >>>>> noise than low level mixers (like the HP10514A). >>>>> When choosing a mixer for this for phase noise measurement applications >>>>> one may actually need to measure the phase noise characteristics of >>>>> candidate mixers. >>>>> >>>>> >>>> >>>> >>>>> Bruce >>>>> >>>>> >>>> Wow, a good overview, Bruce! >>>> >>>> But remain the questions: >>>> which are these high level mixers, are they readily available? >>>> Are they affordable? >>>> Perhaps not, why are they then not applied more often? >>>> >>>> Arnold >>>> _______________________________________________ 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.
