Hi Sure never seen any of them on any gear in my junk pile.
I also never seen a customer ask for them as an output connector on an oscillator. I wonder how common they actually are. Bob On Feb 27, 2010, at 9:59 PM, Bruce Griffiths wrote: > Actually there are miniature twinax style connectors, for example: > http://www.amphenolrf.com/products/twinbnc.asp?N=0&sid=4B8860805409E17F&; > <http://www.amphenolrf.com/products/twinbnc.asp?N=0&sid=4B8860805409E17F&;> > > Bruce > > Bob Camp wrote: >> Hi >> >> I don't even have the counter and already we're butchering it.... >> >> The big issue is suitable twin-ax connectors and cable. I have both, but >> they are *big*. They never really made it into the world of miniature >> connectors and miniature cable. >> >> Shielded twisted pair would be another option. That eliminates the cable as >> an issue. Small connectors (BNC drop in) are still an issue though. >> >> Bob >> >> >> On Feb 27, 2010, at 9:48 PM, Bruce Griffiths wrote: >> >> >>> Since the input amplifier and trigger circuit are located on a small >>> daughter board it wouldn't be too difficult to replace this with an LVDS to >>> CML stage. >>> The only remaining isue would be what input connector to use (twinax??, >>> SATA??). >>> >>> Bruce >>> >>> Bob Camp wrote: >>> >>>> Hi >>>> >>>> Gee, LVDS what an unusual approach :).... >>>> >>>> It would be nice if these instruments had a balanced input. Common mode >>>> noise is indeed an issue in a lot of cases. >>>> >>>> Of course wrapping the coax headed to the counter 10X around a fairly >>>> large core can help things a bit. >>>> >>>> Bob >>>> >>>> >>>> On Feb 27, 2010, at 9:32 PM, Bruce Griffiths wrote: >>>> >>>> >>>> >>>>> If one is feeling paranoid about ground loop noise (and wishes to avoid >>>>> transformers, optoisolators , or fibre optics), etc one could always use >>>>> an LVDS driver with a batter powered(?) LVDS to CMOS receiver/translator >>>>> right at the 5370A/B input BNC connector. >>>>> This may be useful for a DMTD system that uses a 5370A/B. >>>>> >>>>> Bruce >>>>> >>>>> Bob Camp wrote: >>>>> >>>>> >>>>>> Hi >>>>>> >>>>>> AC cmos will easily drive an L pad to match a 50 ohm cable at these >>>>>> levels. That's true at either 3.3 or at 5.0 volts. There are a lot of >>>>>> cmos families out there that beat AC for speed and match the output >>>>>> drive capability. >>>>>> >>>>>> Bob >>>>>> >>>>>> >>>>>> On Feb 27, 2010, at 9:12 PM, Bruce Griffiths wrote: >>>>>> >>>>>> >>>>>> >>>>>> >>>>>>> 1) One method with 5V CMOS is to add a resistive voltage divider at the >>>>>>> CMOS driver output with a 50 ohm output impedance at the tap that >>>>>>> drives the 5370A/B input. >>>>>>> >>>>>>> 2) If one has a 5V 50 ohm driver (eg Thunderbolt PPS output) use a 50 >>>>>>> ohm attenuator at the 5370A/B input. >>>>>>> For a 5370A an attenuation of at least 11dB is required. >>>>>>> For a 5370B an attenuation of at least 3dB is required. >>>>>>> >>>>>>> 3) One can always use the 10x input attenuation setting built in to the >>>>>>> 5370A/B however this reduces the signal swing to 0.5V at the trigger >>>>>>> amplifier input (5V CMOS input). >>>>>>> >>>>>>> 4) Attenuate the output of the logic signal by a factor of 2 and use an >>>>>>> npn emitter follower to drive the 50 ohm load. >>>>>>> >>>>>>> 5) Use 3.3V CMOS signal levels for the 5370B. >>>>>>> >>>>>>> 6) Use a current mode emitter or source coupled switch to drive the >>>>>>> 5370A/B input. >>>>>>> >>>>>>> The switching jitter of the above drivers will be much lower than the >>>>>>> internal noise of the 5370A/B as long as HCMOS or faster logic is >>>>>>> employed. >>>>>>> >>>>>>> Bruce >>>>>>> >>>>>>> >>>>>>> Bob Camp wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>>> Hi >>>>>>>> >>>>>>>> Which *still* carefully avoids the issue of how ..... >>>>>>>> >>>>>>>> Bob >>>>>>>> >>>>>>>> >>>>>>>> On Feb 27, 2010, at 8:52 PM, Bruce Griffiths wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>> Oops! a small correction (2nd paragraph): >>>>>>>>> >>>>>>>>> For the 5370A attenuating the 5V CMOS signal to a 1V swing with the >>>>>>>>> threshold set to 0.5V is close to optimum. >>>>>>>>> An input signal with limits of 0V and +1.4V with a trigger threshold >>>>>>>>> of 0.7V is the maximum usable (for high performance). >>>>>>>>> An input signal with limits of 0V and +0.3V with a trigger threshold >>>>>>>>> of 0.15V is the minimum usable (for high performance). >>>>>>>>> >>>>>>>>> For the 5370B attenuating the 5V CMOS signal to a 2V swing with the >>>>>>>>> threshold set to 1V is close to optimum. >>>>>>>>> An input signal with limits of 0V and +3.5V with a trigger threshold >>>>>>>>> of 0.7V is the maximum usable (for high performance). >>>>>>>>> An input signal with limits of 0V and +0.3V with a trigger threshold >>>>>>>>> of 0.15V is the minimum usable (for high performance). >>>>>>>>> >>>>>>>>> Thus using the PPS output (~270 ohm is series with a 5V 74AC04 >>>>>>>>> output) from a Synergy evaluation board that uses an M12M or M12+ GPS >>>>>>>>> timing receiver to drive the inputs (with a 0-750mV signal) of a >>>>>>>>> 5370A or 5370B is well within the recommended input signal range for >>>>>>>>> high performance. >>>>>>>>> This avoids having to adding an external 5V 50 ohm driver that some >>>>>>>>> would use. >>>>>>>>> >>>>>>>>> Bruce >>>>>>>>> >>>>>>>>> Bob Camp wrote: >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>>> Hi >>>>>>>>>> >>>>>>>>>> So exactly how did you know that I bought a (cheap) 5370B a few >>>>>>>>>> hours ago on the e-place and was just about to ask about how best >>>>>>>>>> to use it. >>>>>>>>>> >>>>>>>>>> Hmmmm....... >>>>>>>>>> >>>>>>>>>> Bob >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On Feb 27, 2010, at 7:01 PM, Bruce Griffiths wrote: >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>>> The attached excerpts from the 5370A and 5370B manuals indicate >>>>>>>>>>> that for best performance, that the common practice of driving the >>>>>>>>>>> 5370A/B 1x inputs directly from a 5V CMOS logic signal is a bad >>>>>>>>>>> idea. >>>>>>>>>>> >>>>>>>>>>> For the 5370A attenuating the 5V CMOS signal to a 1V swing with the >>>>>>>>>>> threshold set to 0.5V is close to optimum. >>>>>>>>>>> An input signal with limits of 0V and +1.4V with a trigger >>>>>>>>>>> threshold of 0.7V is the maximum usable (for high performance). >>>>>>>>>>> An input signal with limits of 0V and +0.3V with a trigger >>>>>>>>>>> threshold of 0.15V is the minimum usable (for high performance). >>>>>>>>>>> >>>>>>>>>>> For the 5370A attenuating the 5V CMOS signal to a 2V swing with the >>>>>>>>>>> threshold set to 1V is close to optimum. >>>>>>>>>>> An input signal with limits of 0V and +3.5V with a trigger >>>>>>>>>>> threshold of 0.7V is the maximum usable (for high performance). >>>>>>>>>>> An input signal with limits of 0V and +0.3V with a trigger >>>>>>>>>>> threshold of 0.15V is the minimum usable (for high performance). >>>>>>>>>>> >>>>>>>>>>> Bruce >>>>>>>>>>> >>>>>>>>>>> <5370ATriggering.png><5370BTriggering.png>_______________________________________________ >>>>>>>>>>> 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. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> _______________________________________________ >>>>>>>>>> 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. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>> _______________________________________________ >>>>>>>>> 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. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> 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. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> _______________________________________________ >>>>>>> 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. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> _______________________________________________ >>>>>> 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. >>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >>>>> >>>>> >>>>> >>>> _______________________________________________ >>>> 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. >>>> >>>> >>>> >>> >>> >>> _______________________________________________ >>> 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. >>> >>> >> >> _______________________________________________ >> 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. >> >> > > > > _______________________________________________ > 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. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and 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