Thanks Magnus! On 14 June 2010 20:45, Magnus Danielson <mag...@rubidium.dyndns.org> wrote: > Steve, > > On 06/14/2010 04:49 AM, Steve Rooke wrote: >> >> On 14 June 2010 10:46, Magnus Danielson<mag...@rubidium.dyndns.org> >> wrote: >> >>> Still puts it in the mid-tau range as a method. The useful range and >>> precision of a particular implementation of the method will vary. >> >> By putting a GPSDO in the usual place of the DUT and putting the 10811 >> in place of the reference oscillator it could work well beyond the >> 1000s point. CAVEAT: this only works for a DUT that has an EFC that is >> reasonably linear. > > EFC linearity will remain an issue for analog oscillators. The oscillator > gain will differ depending on offset voltage and temperature. > >>>> So if you are just thinking about the TPLL for taking ADEV data from 0.1 >>>> to 1000 sec, then you're are missing 90% of the other useful stuff it >>>> can do as good or better than most anything thing else out there, and >>>> all for the same $10 (my cost). >>> >>> The typical price-tag of a 10811 is in 100-150 USD. I think it is >>> reasonable >>> to assume that a TPLL weighs in at about 200 USD with all support mixers, >>> amplifiers, ADCs etc. It's not bad, but if you don't have the parts >>> that's >>> about what you need to spend at least. >> >> If you really wanted to be a scrooge, you could open the case on one >> of those plethera of HP intruments and temporarily borrow that 10811 >> that is just sitting there. As for something like a ADC, you could >> find a DAQ on fleeBay which could do duty here and also be a useful >> tool for general purpose use. Heck, you can use your sound card to >> digitize the EFC, provided it is DC coupled. > > If you don't have the parts, then it will set you back with at least that > number. If you have the parts, you have already invested in them and payed > for them that way. You may be lucky to be given the oscillator, but honestly > you can't rely on that. I just want the cost numbers to be more reasonably > given. It is still a fairly cheap solution. > >>>> BTW, with a couple of minor configuration changes, the TPLL BreadBoard >>>> can be transformed into a LPLL, >>>> so the usefulness of the basic Universal TPLL BB circuit has even more >>>> possibilities. >>>> In fact one could make yet another list of all the additional things it >>>> can do with no added cost, >>>> just by changing a few jumpers and values. >>>> But those things are for later discussions, one windmill at a time. >>> >>> Measurement of phase noise is what the LPLL is good at, especially when >>> done >>> in cross-correlation mode. Interferometric setups use the mixers better. >>> Both these techniques could be used for LPLL and TPLL measures. >> >> Do you have some pointers to these setups please Magnus? > > Look at Enrico Rubiolas site where his publications and presentations should > be inspirational. His focus is on LPLLs. but the methodology of > cross-correlation and interferometric setup should be as viable in the TPLL > world. > > Cheers, > Magnus > > > _______________________________________________ > 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. >
-- Steve Rooke - ZL3TUV & G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein _______________________________________________ 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.