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 -- time-nuts@febo.com >>> 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 -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > >

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 -- time-nuts@febo.com >>>> 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 -- 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.