Dictionary of Radar Terms
"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",
"N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"

The graphic shows all the common styles of BNC connectors: including; a 50 ohm Terminating BNC, Ground Terminating BNC, Twist-on BNC, BNC-Tee, Female-to-Female BNC, and Bulk-Head BNC.

Graphic of different styles of BNC Connectors
Styles of BNC Connectors

BNC: The Bayonet Navy Connector operates best at frequencies up to about 4 GHz; beyond that it tends to radiate electromagnetic energy. The BNC can accept flexible cables with diameters of up to 6.35 mm (0.25 in.) and characteristic impedance of 50 to 75 ohms. BNC connectors are the most commonly used connector for frequencies under 1 GHz. Many other similar connectors are available, a few of them are compared to the BNC styles as; Frequency Range vs Connector Type.

BNC Connector attached on a Coax Cable
BNC Coaxial Cable

The BNC connector has an outer conductor [normally ground] and an inner conductor which normally carries the signal. However there is no guarantee that the outer conductor, or shield will be grounded or even connected. Some applications may connect the shields to the metal equipment cases, which them selves may not be grounded. A BNC connector is used with a Coax Cable. There are two methods of attaching the Coax Cable to the BNC connector, either crimping or soldering. If the connector has a solder cup [solder pocket] than the wire is soldered, but the wire is crimped if the connector has a crimp attachment.

The TNC Connector or SMA Connector are a similar style connector, but smaller. Refer here for Coax Connector Manufacturers.

BNC Adapter: A connector with a BNC fitting on one end and another style connector on the other end. As in the SMA to BNC adapter shown to the right. An connector would also be considered an adapter if it had the same type connector on both ends, as in male-to-male adapter. Read more on BNC Adapters.

SSMA Jack to BNC Jack Adapter

BNC Attenuator: A BNC adapter that that offers some amount of impedance to the signal passing between the two ends of the connector. The example below has a male connector on one end and a female connector on the reverse end.

Jack-to-Plug BNC Adapter

BNC to Banana Jack: A connector that adapts a Banana Jack or Plug to a BNC connector. The BNC end could also be either a plug or a jack. A BNC to twin binding post is shown below right, which is designed to translate discrete wires into a BNC interface. Although a Banana jack also has wire binding posts, the difference is in the intended function. Read more on Banana Jack Adapters.

BNC Barrel. [BNCFF] Normally refers to a female-to-female connector, which is also called an adapter. A BNC barrel is shown in the graphic at the top of the page. The graphic to the right is a coaxial barrel which might be found on a TV connection.

Female-to-female Coaxial Barrel Adapter

Of course a male-to-male connector is also available [BNCMM], but is always called an adapter and not a barrel [shown below].

BNC Board Mount. Same as a PCB mount, and is either a female receptacle or male connector.

BNC Bulkhead Mount. The same as a panel mount connector. A BNC bulkhead connector may be either front mount or rear mount and refers to which side of the panel receives the jam nut to secure the connector to the panel. A front mount connector is inserted into the front of the panel, the jam nut is secured to the connector to the rear of the panel. In a rear mount, the connector is inserted from the rear of the panel and the jam nut attached to the front side of the panel.
Note that the mounting hole cut-out is larger for a rear mount connector, than for a front mount connector. The front mount connector only needs to accept the threaded portion of the connector, while the rear mount type needs to have a hole to accept the barrel of the BNC connector, and the locking pins of the bayonet portion.

BNC Insulated Bulkhead Mount. A BNC connector which has both sides of the connector shell insulated from the bulkhead. The connector shell is insulated from the panel the connector is attached to.

BNC Cap. The term used in MIL-PRF-39012 slash sheet 25 to refer to a BNC cover as part number M39012/25-X015 [for female BNC connectors]. This part makes no connection between the shell or the signal pin so is not a termination, but a protective cover or cap for another BNC connector. The Caps are used to maintain the connector interface free from dust and moisture.

BNC Cover. A protective connection attached to a BNC connector to either protect the signal pins from the environment or from spurious noise. Read more on BNC Connector Dust Covers. A BNC cover is a connector with a connection only on one end, the other side is just a flat plate used as a shield. The mating-end of a BNC cover may contain either a female or male connection.

BNC Cross Adapter. A connector with four ports in the shape of a cross, for example a Male/female-female-female cross. Or in this case a FFFF coax adapter, or 4-port female adapter.

4-Port Coaxial Female Cross Adapter

BNC 'F' Adapter. BNC Male to Double BNC Female [in the shape of the letter 'F'].

BNC Flange Mount. A style of BNC that contains a flange for bulk-head or panel mounting. A flange could have any type of termination on either end. For example a flange mount connector could have either a male or female connector on one end, and a solder cup or crimp lead on the other end [cabled end]. Refer to the graphic for a Flange mount BNC plug using a solder cup for wire lead attachment.

BNC Goalpost Adapter. BNC Male to Double BNC Female [in the shape of a 'Y']

BNC Jack. Is the female socket of a BNC pair. A female connector.

BNC Panel Mount. Uses a flat surface on the body of the BNC connector which is used as a stop, so the connector does not pass all the way through the panel. The other side of the connector than uses a jam nut to secure the connector to the panel.

BNC PCB Mount. A connector used to attach to a printed circuit board. Normally a through-hole connector with a center conductor or pin, that carriers the signal, and two to four additional pins that carrier the out conductor or shield. The connectors may be straight or right angle and in some cases uses a plastic body. In some cases a right angle connector could be called a angle jack and may also include a bulkhead attachment.

BNC Plug. Is the male plug of a BNC pair.

BNC L Connector. A right-angle BNC connector. A male to female L connector is shown on the BNC T Connector Variations page, while a solder-cup to female connector is shown to the right. In some cases the 'L' shape, is still called a 'T' connector.

BNC Off-set T Connector. An alternate name for a BNC T connector which has one of the terminals off-set from the other. Also known as an off-set T. [BNC T Connector Variations]. An off-set 'T' connector is a slight variation to the normal T and used to address space requirements.

BNC Right Angle. A BNC connector or adapter that makes a right angle bend, as shown by the Male-to-Female connector. A bulk-head or panel mount version is shown in the right side-bar.

SSMA Jack to BNC Y Adapter, Female-Male-Male style

BNC Shorting Plug. A BNC terminator that connects or shorts the outer line [shell] with the inner line [signal pin]. Assuming the cable shield is grounded, than this may also be referred to as a zero ohm termination, or grounded termination. There are three parts used with MIL-PRF-39012 slash sheet [SS] 25 to refer to a BNC shorting plug [for female BNC connectors] as part number M39012/25 -X016 [Bead chain], -X017 [Safety chain], and -X018 [Wire rope].

BNC Socket. A female connector. A BNC Jack.

BNC T Connector. Is a connector with three ports, normally a male connector [as the base] and two female connectors [which form the tee]. However, although less common, a T connector could have a single female port and two male ports. Read more on BNC T Connectors. Additional graphics are available, showing different BNC T Connector Variations, including a Tee with all female-ports. Common styles include: jack-jack-plug, jack-jack-jack, and jack-plug-jack. The male connector is also called pin side, and the female a socket end. Remember a 'T' connector will split or attenuate the signal, so only use them when required. The Male [Plug] to Female-Female [Jack] 'T' above is used to split a signal from a component to two different lines. This style Tee connector is used with 10Base2 and 10Base5 Ethernet between a NIC card, a 50 ohm terminator and the Ethernet signal. In some cases a T connector is used to add line termination; Male to device, 1 Female has the line coming in the other receives a Dummy load.

BNC Termination. A connector with a single mating section that is used to terminate a BNC cable run. A BNC Termination holds either a 50 or 75 ohm resistor to terminate the line. The resistor is connected between the center pin contact [signal] and the outer shell [ground]. Read more on BNC Terminators. As shown above a 50 ohm BNC termination is abbreviated as BNC-Term-50. A grounded termination is also shown as a BNC-Term-GND part. There is a thru-port 50 or 75 ohm termination, with connectors on both ends, however its not very common and could be considered an attenuation rather than a termination.

BNC Y Adapter. A 3-terminal BNC connector in the basic shape of the letter Y. The common connections are a single male end and two female ends. Also known as a Goalpost Adapter, in the shape of a 'Y'.

SSMA Jack to BNC Y Adapter, Female-Male-Male style

In-Series Adapter. An adapter with a BNC connector on both ends. A male-to-male adapter is shown, although a female-to-female is available and called a barrel. Also refer to BNC Adapters for a larger graphic of both types.

BNC In-Series Adapter, Male-to-Male Style Adapter
Male-to-Male Straight Plug

Additional notes; As already indicated wire attachment may be made either by a crimp or solder method. Using the crimp lead as an example; the attachments may be made to a free BNC connector [BNC Crimp], used at the end of a cable, or a panel mountable BNC connector [Bulkhead Crimp].

Construction notes; Connectors may be classified as hermetic or non-hermetic, and used depending on the application and cost. A gas-sealed Hermetic connector will also be water-tight. The more common non-hermetic style connector would be found indoors shielded from the environment. However there are connectors that combine both types, as in some bulkhead connectors. The exterior side of a bulkhead connector could be hermetically sealed while the portion of the connector that resides within the equipment chassis [on the other side of the bulkhead] is not hermetically sealed.

A number of military specifications call out BNC connectors, usually in reference to a coaxial RF connector.

PC motherboard

Distributor rolodex Electronic Components Electronic Equipment EDA CDROM Software Engineering Standards, BOB card Cabled Computer Bus Electronic Engineering Design Table Conversion DB9-to-DB25.
DistributorsComponents Equipment Software Standards Buses Design Reference