I like Bob's suggestion about using an L-pad. Even if the line driver *is* happy driving 50 ohm line (which I was admittedly assuming), the L-pad approach will keep the driver cooler which will likely reduce warmup drift of its propagation delay as well as extend its lifetime.
Dana On Thu, Jul 2, 2020 at 9:20 AM Bob kb8tq <[email protected]> wrote: > Hi > > Probably the easiest approach is an L pad at the input to the measurement > device. > Something like a 470 ohm in series and a 120 ohm to ground. A 50 ohm pad > may not make the line driver in the source device very happy …. > > Something more exotic would be to do a distribution amp. Use a NC7SZ125 at > the > input so it’s 5V tolerant. Run however many of them you need to drive the > desired > number of outputs. Power it all off of 2V and you have 2V p-p output(s). > > Keep in mind that 2V p-p “logic” signals may or may not trigger CMOS level > stuff > powered off of 3.3V. CMOS running on 5V gets into the “not going to > happen” > area. > > Bob > > > > > On Jul 1, 2020, at 9:37 PM, VE7HR <[email protected]> wrote: > > > > Are there any suggested method to reduce your 1 PPS signal to a safe > level for your test equipment? > > It seems like my HP Z8316A is outputting slightly more than 5V into 50 > Ohms. > > > > Up till now I have been using a 10 MHz output from the Z3816A. But I > understand 1PPS is a better signal to put to Channel A. > > > > My HP 5372A seems to default to 2V Max level if you hit instrument > default. I am starting to like it so I don’t want to trash an input > module. > > > > I think I might try a TICC in the near future but for now I will have to > slum with the vintage HP iron. > > > > Thanks > > Dave > > VE7HR > > > > Sent from my iPhone > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
