Seems that the 3.3V bidirectional drivers connected to the SMA connectors of one TimeCard in output mode can not be connected to another TimeCard input with 50 Ohm termination since 0.53.3V is lower then Input HIGH (0.653.3V) level specified for nc7wv125-d.
I may oversee something but a signal generator with a configuration of 3.3V square wave signal will generate 3.3V pulses with the termination resistor connected while the TimeCard output will be only half of that.
Is this intended?
[1] https://github.com/opencomputeproject/Time-Appliance-Project/blob/master/Time-Card/HW/ECAD/Latest/TimeCardV9_Schematic_8-28-2023.pdf
[2] https://www.onsemi.com/download/data-sheet/pdf/nc7wv125-d.pdf