Hi Chris: If the source of a pulse is 50 Ohms and it's TTL level at open circuit ( 0 to 5 volts) and the load is 50 Ohms, then when you connect a 50 Ohm load the pulse is 0 to 2.5 volts and so setting the trigger to 2.5 volts is just on the edge of not working. It's best to put a "T" connector and have a look with a scope. If the above is the case then a trigger level of 1.25 might work better.
Have Fun, Brooke Clarke -- w/Java http://www.PRC68.com w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml http://www.precisionclock.com Christopher Hoover wrote: >Attached is what I'm seeing in terms of adev and mdev on my "new" FTS >4050. > >The performance is worse than I had expected, as compared to the >datasheet. > >I'm not 100% confident in my test setup, but I'm not seeing any obvious >outliers in the data. > >Test setup is as follows: > >Counter: HP 53132A >Timebase: external, 10MHz from Z3801A >Start: 1 PPS from Z3801A, DC, 50Z, 2v5 trigger level >Stop: 1 MHz from FTS 4050, AC, 50Z, auto trigger > >-ch > > > > ------------------------------------------------------------------------ > > >------------------------------------------------------------------------ > >_______________________________________________ >time-nuts mailing list >[email protected] >https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
