The BNC connector uses a bayonet-style locking mechanism requiring only a quarter-turn to secure. It is the standard interface for composite video, oscilloscope probes, and older Ethernet networks. The design maintains the characteristic impedance of the cable, typically 50 or 75 ohms, preventing signal reflection at the junction.
Grab a 50-ohm BNC connector for that oscilloscope lead, the 75-ohm ones will cause reflection issues here.
Never force a 75-ohm BNC plug into a 50-ohm jack, as the center pin diameter differs and will permanently stretch the female contacts.
Related terms
Coaxial cable
A copper transmission line built with a central conductor surrounded by an insulating layer and a braided metallic shield.
Composite video, blanking, and sync
An analog television signal format that combines picture data and synchronization pulses on a single wire.
RJ
A standardized physical network interface for connecting telecommunications equipment.