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

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

At 07:01 PM 2/27/2010, Bruce Griffiths wrote... >For the 5370A attenuating the 5V CMOS signal to a 1V... > >For the 5370A attenuating the 5V CMOS signal to a 2V... ITYM "5370B" for the second part.

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 -- 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. > >

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 -- 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. >> >> > > > > _______________________________________________ > 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. >

Mike S wrote: > At 07:01 PM 2/27/2010, Bruce Griffiths wrote... >> For the 5370A attenuating the 5V CMOS signal to a 1V... >> >> For the 5370A attenuating the 5V CMOS signal to a 2V... > > ITYM "5370B" for the second part. > > Yes, a result of cutting and pasting. Bruce

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 -- 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. >>> >>> >>> >> >> >> _______________________________________________ >> 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. > >

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 -- 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. >>>> >>>> >>>> >>> >>> >>> _______________________________________________ >>> 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. >> >> > > > > _______________________________________________ > 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. >

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 -- 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. >>>>> >>>>> >>>>> >>>>> >>>> >>>> _______________________________________________ >>>> 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. >>> >>> >>> >> >> >> _______________________________________________ >> 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. > >

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 -- 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. >>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >>>> >>>> >>>> >>> >>> >>> _______________________________________________ >>> 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. >> >> > > > > _______________________________________________ > 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. >

In general, what about the old National "damn fast" and super damn fast" LH0032 & LH0033? I used to use a lot of those in my designs many years ago. - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960

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 -- 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. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> _______________________________________________ >>>>>> 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. >>>>> >>>>> >>>>> >>>>> >>>> >>>> _______________________________________________ >>>> 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. >>> >>> >>> >> >> >> _______________________________________________ >> 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. > >

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 -- 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. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> _______________________________________________ >>>>>>> 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. >>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >>>> >>>> >>>> >>> >>> >>> _______________________________________________ >>> 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. >> >> > > > > _______________________________________________ > 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. >

Mike Feher wrote: > In general, what about the old National "damn fast" and super damn fast" > LH0032& LH0033? I used to use a lot of those in my designs many years ago. > - Mike > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 > The LH0032 was a fast FET input opamp. I presume you meant the LH0033 and LH0063? Their slew rate is adequate to ensure that the 5370A/B trigger jitter is insignificant. However they need a negative supply as well as the positive supply when being driven by a 3.3V or 5V CMOS output. Bruce

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 -- 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. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> 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. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> _______________________________________________ >>>>>> 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. >>>>> >>>>> >>>>> >>>>> >>>> >>>> _______________________________________________ >>>> 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. >>> >>> >>> >> >> >> _______________________________________________ >> 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. > >

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 -- 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. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>> _______________________________________________ >>>>>>>>> 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. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> _______________________________________________ >>>>>>> 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. >>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >>>> >>>> >>>> >>> >>> >>> _______________________________________________ >>> 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. >> >> > > > > _______________________________________________ > 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. >

You could look at a surplus F16 (probably wont fit in your garage though) or similar STP was heavily used in MIL STD 1553 avionics buses. Bruce Bob Camp wrote: > 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 -- 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. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> _______________________________________________ >>>>>>>>>> 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. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> 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. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> _______________________________________________ >>>>>> 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. >>>>> >>>>> >>>>> >>>>> >>>> >>>> _______________________________________________ >>>> 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. >>> >>> >>> >> >> >> _______________________________________________ >> 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. > >

Hi MIght have to move a few things in the shed to fin in an F16. If they were used in quantity there aught to be cable and connectors out there. The only reason I have the stuff I do is good old IBM and their approach to networking back in the old days. It would be tough to properly drive an R-390 otherwise. Bob On Feb 27, 2010, at 10:10 PM, Bruce Griffiths wrote: > You could look at a surplus F16 (probably wont fit in your garage though) or similar STP was heavily used in MIL STD 1553 avionics buses. > > Bruce > > Bob Camp wrote: >> 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 -- 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. >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>> _______________________________________________ >>>>>>>>>>> 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. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>> _______________________________________________ >>>>>>>>> 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. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> _______________________________________________ >>>>>>> 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. >>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >>>> >>>> >>>> >>> >>> >>> _______________________________________________ >>> 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. >> >> > > > > _______________________________________________ > 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. >

Bob Camp <lists@rtty.us> wrote: > Hi > > MIght have to move a few things in the shed to fin in an F16. > > If they were used in quantity there aught to be cable and connectors > out there. The only reason I have the stuff I do is good old IBM and > their approach to networking back in the old days. It would be tough > to properly drive an R-390 otherwise. R-390 or S/390? :-) -ls-

Hi R-390 and / or R-390A Not a lot of IBM stuff here. I can fit in a F-16 only because I've avoided the IBM stuff.... Bob On Feb 27, 2010, at 10:18 PM, Larry Snyder wrote: > Bob Camp <lists@rtty.us> wrote: >> Hi >> >> MIght have to move a few things in the shed to fin in an F16. >> >> If they were used in quantity there aught to be cable and connectors >> out there. The only reason I have the stuff I do is good old IBM and >> their approach to networking back in the old days. It would be tough >> to properly drive an R-390 otherwise. > > R-390 or S/390? > :-) > -ls- > > > _______________________________________________ > 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. >

here is a two center pin type of BNC, presumably for a balanced twisted pair or twin ax type cable. The shape of the dielectric allows proper mechanical mating. Stan, W1LE Cape Cod 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. >

I need the red plastic digit cover/window [approximately 1 3/4" x 14 3/4"] to complete the repair of a HP 5370 counter/timer. I don't care if it says 5370A or B. I assume that no major change occurred other than the unit identifier changing. Perhaps someone can correct me if I am wrong in making this assumption. It would be nice to get the bezel clip/strip too, however I suspect that they tend to disintegrate during removal of the red display cover. Does anyone have this available from a parts chassis in their lab? I would be happy to pay a reasonable price plus postage. I am located in Kalamazoo, Michigan, USA. Jim Cotton n8qoh

I have a bnc type connector with two pins inside the shield on a FTS cesium standard labeled DS1 must be a phone industry jack. Stanley ----- Original Message ---- From: Bob Camp <lists@rtty.us> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Sat, February 27, 2010 8:53:16 PM Subject: Re: [time-nuts] Achieving maximum performance when driving 5370A/B inputs 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 -- 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. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>              >>>>>>> _______________________________________________ >>>>>>> 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. >>>>>> >>>>>> >>>>>> >>>>>>          >>>>> >>>>> _______________________________________________ >>>>> 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. >>>> >>>> >>>>      >>> >>> >>> _______________________________________________ >>> 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. >> >>  > > > > _______________________________________________ > 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.

Mike Feher wrote: > In general, what about the old National "damn fast" and super damn fast" > LH0032 & LH0033? I used to use a lot of those in my designs many years ago. > - Mike > > Gotta really decouple the power supplies on those puppies...

Bob Camp wrote: > 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: >>> There's a variety of these kind of things. You see them in MIL-STD-1553B systems, among others. Triax is also fairly common as a connector for "shielded twisted pair". There are also twisted pair inserts for the DB-25 sized shell (actually a quad pair with 4 inserts). The one that has one pin and one socket on each side is a much better strategy than the one that has 2 pins on one connector and 2 sockets on the other.

These were used on some measuring instruments to provide a balance 'guarded' input. The shield around the balanced conductors provided a ground between the DUT and the measuring equipment that was not connected to the input. IIRC this was for very low level signals. 73 Glenn WB4UIV At 10:06 PM 2/27/2010, you wrote: >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 -- 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. > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>> _______________________________________________ > >>>>>>>>> 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. > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>> _______________________________________________ > >>>>>>> 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. > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>> > >>>>> _______________________________________________ > >>>>> 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. > >>>> > >>>> > >>>> > >>> > >>> > >>> _______________________________________________ > >>> 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. > >> > >> > > > > > > > > _______________________________________________ > > 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.

found a picture of the Twin BNC here: http://drawings.amphenolrf.com/pdf/172.pdf

Is that buttermilk or blueberry batter? :-) Don ----- Original Message ----- From: "Bruce Griffiths" <bruce.griffiths@xtra.co.nz> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Saturday, February 27, 2010 7:32 PM Subject: Re: [time-nuts] Achieving maximum performance when driving 5370A/B inputs > 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 -- 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. >>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >>>> >>>> >>>> >>> >>> >>> _______________________________________________ >>> 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. >> >> > > > > _______________________________________________ > 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.

The 0032 was an op-amp and the 0033 and 0063 a buffer. The 0063 was a high power/higher slew-rate version. They were, and still are, great to use. I do have some 0032s and 0033s. Never played with the 0063. 73 - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bruce Griffiths Sent: Saturday, February 27, 2010 9:56 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Achieving maximum performance when driving 5370A/B inputs Mike Feher wrote: > In general, what about the old National "damn fast" and super damn fast" > LH0032& LH0033? I used to use a lot of those in my designs many years ago. > - Mike > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 > The LH0032 was a fast FET input opamp. I presume you meant the LH0033 and LH0063? Their slew rate is adequate to ensure that the 5370A/B trigger jitter is insignificant. However they need a negative supply as well as the positive supply when being driven by a 3.3V or 5V CMOS output. Bruce _______________________________________________ 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.

Hi The D series shell with multiple "normal" inserts is the solution I've seen a lot of. Bob On Feb 27, 2010, at 10:54 PM, jimlux wrote: > Bob Camp wrote: >> 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: > > > There's a variety of these kind of things. You see them in MIL-STD-1553B systems, among others. Triax is also fairly common as a connector for "shielded twisted pair". There are also twisted pair inserts for the DB-25 sized shell (actually a quad pair with 4 inserts). > > The one that has one pin and one socket on each side is a much better strategy than the one that has 2 pins on one connector and 2 sockets on the other. > > _______________________________________________ > 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. >