What Is a BNC Connector?
A BNC Connector (Bayonet Neill-Concelman connector) is is used to connect coaxial cables.
The bayonet mount, a locking mechanism, allows quick and easy connection, disconnection, and fastening by rotating the ring on the end of the connector.
Uses of BNC Connectors
Among various types of coaxial cable connectors, BNC Connectors are widely used as signal cables for video, communication, and measurement equipment because of their excellent frequency characteristics and compact size.
In many research facilities, BNC connectors are routinely used to connect cables required for sending and receiving trigger signals between scientific instruments, transmitting data from detectors, and remotely operating experimental equipment.
Principle of BNC Connectors
1. Connection of BNC Connectors
The structural feature of the BNC Connector is a bayonet mechanism that does not use screws. The adapter is pushed in, aligned with the receptacle’s guide, and locked by rotating the ring at the end. This mechanism not only maintains a stable connection between connectors, but also allows for quick and easy connection and disconnection.
Typically, the male connector is attached to the cable and the female connector is attached to the panel of the equipment.
2. Role of BNC Connectors in Communications
Coaxial cables to which BNC Connectors are attached are used to transmit and receive high-frequency multi-megahertz signals.
The inner conductor wire is protected by a double insulation layer, and a plastic sheath is wrapped around the outer conductor wire. It is capable of high-speed and stable signal transmission at 10 MHz/s while minimizing electromagnetic interference and signal loss.
BNC Connectors are structurally designed to transmit and receive signals stably between connected devices while preventing noise from entering through the connection.
Types of BNC Connectors
There are two types of BNC connectors in terms of impedance. Those used for measurement and communication have a characteristic impedance of 50Ω, while those used for video signals have a characteristic impedance of 75Ω. These connectors use contact pins that are thinner in diameter than the 50Ω contact pins.
Since 50Ω BNC connectors and 75Ω BNC connectors are different, they cannot be mechanically interconnected, or if they can be, they are often unreliable.
Other Information on BNC connectors
1. Crimp Style BNC connectors
Crimp style BNC connectors are commonly used. Special crimping tools are required for installation. Since crimping tools differ among manufacturers, it is recommended to use the tools indicated by each manufacturer.
The general flow of the installation procedure is as follows:
- Prepare the crimping tool.
- Pass the crimp sleeve through the cable and cut off the outer sheath, outer conductor, and insulation in the dimensions specified by the manufacturer.
- Attach the center rontact to the center conductor and crimp the crimp part specified by the manufacturer.
- Insert the shell between the insulation and outer conductor of the BNC connector.
- Move the crimp sleeve to the position specified by the manufacturer and crimp.
2. Solder-Mounted BNC Connector
Solder-mount BNC connectors are a commonly used mounting method similar to crimp-style BNC connectors.
The general flow of installation is as follows:
- Remove the tightening nut from the shell and take out the cackle parts.
- Thread the cable through the clamping nut, washer, and gasket in this order, and cut off the outer sheath to the dimensions specified by the manufacturer.
- Attach the clamp, fold and trim the outer conductor, and trim the insulation to the dimensions specified by the manufacturer.
- Attach the center contact to the center conductor and solder the manufacturer’s specified part.
- Insert the cable formed by attaching the center contact to the center conductor into the shell and secure it with the tightening nut.