Bayonet Neill-Concelman Connector

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What Does Bayonet Neill-Concelman Connector Mean?

The Bayonet Neill-Concelman Connector (BNC connector) is a type of coaxial RF (Radio frequency) electrical connector that is used in place of coaxial connectors.


A BNC connector connects various radio frequencies up to 3GHz and voltages under 500V DC and are used in electronic architectures such as audio, video and networking. BNC is also used in avionics and high grade analog communications test equipment due to its low-signal-loss architecture. Co-axial ethernet cabling is nearly always terminated with BNC connectors.

Techopedia Explains Bayonet Neill-Concelman Connector

The BNC connector got its name from its bayonet mount locking device and its inventors, Paul Neill of Bell Labs and Carl Concelman of Amphenol Corporation. Its close-fitting connection uses a mount comparable to a knife (bayonet) that is attached onto the end of a rifle.

The basis for the BNC connector occurred as a result of the work done by Octavio M. Salati of Hazeltine Electronics Corporation, who invented a connector for coaxial cables that reduced wave reflection/loss by connecting across the radial surface of the cable and not a terminated cross-section which suffers signal degradation through reflection at a flat cable end.

One of the benefits of the BNC connector is its close-fitting connection. The connection is locked by the BNC male connector that has a pin that fits into the main conducting wire. It is then secured in place with an external ring that turns to a locked position.

A BNC connector can be connected to various types of coaxial cables and typically uses voltages below 500 volts and frequencies below 3 GigaHertz.

The BNC connector is often used with thin Ethernet networks on network cards and cable interconnections that have a 10BASE-2 coaxial cable. It is also used for many types of signal connections like:

  • Serial digital interface and analog signals
  • High-tech video networks
  • Amateur radio antenna connections
  • Electronic test equipment
  • Aviation electronics or avionics

The BNC connector is widely used in electronics although it is being superseded by the LEMO 00 mini-connector that handles higher densities. The HD-BNC connector and the DIN 1.0/2.3 also allow higher density in video broadcasting.

There is also a threaded version of the BNC connector called the threaded Neill-Concelman (TNC) connector. This connector allows higher frequencies than the BNC connector into the microwave bands.


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Margaret Rouse
Senior Editor
Margaret Rouse
Senior Editor

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.