The wiring, as Donald wrote, has been "floating around our department since any of us got here". If you're an amateur, feel free to do what Mark suggests above. If you're a professional, do as I suggested: chuck it and replace it with wiring properly spec'd by someone like Fred or Ted Savage, who know the proper impedance and performance parameters for wiring used in this context.
The whole point of the FIS timing equipment specs is understanding that a timing system is only as good as its weakest link.