BNC (Bayonet Neill-Concelman) connectors are a type of coaxial RF connector used for terminating coaxial cable in a variety of applications. They were originally developed by Paul Neill of Bell Labs and Carl Concelman of Amphenol in the 1950s.
BNC connectors feature a bayonet-style locking mechanism that allows for quick and secure connections. They are available in 50 ohm and 75 ohm versions, with the 50 ohm version being the most common for use in high-frequency applications such as telecommunications, broadcasting, and instrumentation.
The connectors consist of a cylindrical metal body with a center pin that is surrounded by a concentric metal ring. The outer ring is threaded and can be screwed onto a mating connector, while the inner pin is inserted into the center conductor of the coaxial cable. The outer conductor of the cable is then connected to the outer ring of the connector, providing a complete circuit.
BNC connectors are easy to install and remove, making them a popular choice for test and measurement equipment, as well as for use in CCTV security systems and audio equipment. They are capable of operating at frequencies up to 4 GHz, although higher frequency versions are available for specialized applications.
One disadvantage of BNC connectors is that they are relatively large and may not be suitable for use in applications where space is limited. Additionally, the bayonet locking mechanism can become worn over time, which may cause the connection to become loose or intermittent.