Comtech EF Data CRS-300 - Manual (Page 265)

CRS-300 1:10 Redundancy Switch MN/CRS300.IOM
Appendix B Revision 19
B-19
B.4.2 Switch-to-Modem / Modem-to-User, IF Cable (BNC 50Ω Male)
You may use this 50Ω BNC cable used to connect the CRS-280 (70/140 MHz) IF Switch to the Modem.
Figure B-14. IF Cable, BNC 50Ω for CRS-280 (70/140 MHz) IF Switch (PL/0946-2)