About the word clock output of DCS NB

I am going to equip the DCS NB with a word clock BNC cable, but I don’t know whether to choose a 75 ohm cable or a 50 ohm cable, and the manual does not clearly state it, please tell me if you know it, thank you

75 Ohms.

Read the FAQ on the SDIF-2 interface, including the Word-clock out;