BNC connector

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Male 50 ohm BNC connector

Cables with BNC connectors

Adapter between a female BNC connector and banana
plugs

Pulse generators with BNC connectors and
cables.

The BNC (Bayonet Neill Concelman) connector is a very
common type of RF connector used for
terminating coaxial cable.

Contents

1 Use

2 Specifications

3 History

4 Similar
connectors

5 See also

6 References

[edit]
Use

The BNC connector is used for RF signal connections, for analog
and Serial Digital
Interface video signals, amateur radio antenna
connections, aviation electronics (avionics) and many other types
of electronic test
equipment. It is an alternative to the RCA connector when used
for composite video on commercial video devices, although many consumer
electronics devices with RCA jacks can be used with BNC-only commercial
video equipment via a simple adapter. BNC connectors were commonly used on 10base2 thin Ethernet networks, both on
cable interconnections and network cards, though these
have largely been replaced by newer Ethernet devices whose wiring does not use
coaxial cable. Some ARCNET networks use
BNC-terminated coax.

[edit]
Specifications

BNC connectors exist in 50 and 75 ohm versions. Originally all were 50
ohm and were used with cables of other impedances, the small mismatch being
negligible at lower frequencies. The 75 ohm types can be recognized by the
reduced or absent dielectric in the mating
ends. The different versions are designed to mate with each other,[1]
although the impedance mismatch will lead to signal reflections. Typically, they
are specified for use at frequencies up to 4 and 2 GHz, respectively.

NOTE. The physical sizes of the 50 and 75 ohm sockets are slightly different
and can damage the "wrong" plugs.

[edit]
History

The connector was named after its bayonet mount locking
mechanism and its two inventors, Paul Neill of Bell Labs
(inventor of the N connector) and Amphenol
engineer Carl Concelman (inventor
of the C
connector), and is much smaller than both the N and the C connectors. Other
backronyms
the BNC has picked up over the years include: "Baby Neill-Concelman", "Baby N
connector", "British Naval Connector", "Bayonet Nut Connector". The basis
for the development of the BNC connector was largely the work of Octavio M.
Salati, a graduate of the Moore School of Electrical Engineering of the
University of Pennsylvania (BSEE '36, PhD '63). He filed a patent in 1945
(granted 1951) while working at Hazeltine Electronics Corporation for a
connector placed on coaxial cables that would minimize wave reflection/loss.[2]

[edit]
Similar connectors

A threaded version of the BNC connector, known as the TNC
connector (for Threaded Neill-Concelman) is also available. It has
superior performance to the BNC connector at microwave frequencies.

Triaxial BNC connector

BNC connectors are commonly used in NIM electronics, but they are now
often replaced by LEMO 00 miniature connectors which
allow for higher densities. For higher voltages, MHV and SHV
connectors are typically used. MHV connectors are easily mistaken for BNC
connectors and can be made to mate with them by brute force. The SHV connector
was developed as a safer alternative to MHV connectors and will not intermate
with ordinary BNC connectors.

In USSR, BNC connectors were copied as SR-50 (Russian: СР-50) and SR-75
(Russian: СР-75) connectors. These connectors have slightly different dimensions
(as a result of recalculating from Imperial to Metric system), but are generally
interchangeable with BNC, sometimes with force applied.

Twin BNC connectors use the same bayonet latching shell as an ordinary
BNC connector but contain two independent contact points (one male and one
female), allowing the connection of a 78 ohm or 95 ohm shielded differential pair such
as RG-108A.[3]
They are capable of operation at 100 MHz and 100 volts. Twin BNC connectors will
not intermate with ordinary BNC connectors.

Triaxial connectors are a
variant on BNC which carry both a signal and guard as well as ground conductor.
These are used in sensitive electronic measurement systems, particularly of Keithley
manufacture. Early ones were designed with just an extra inner conductor, but
later tri-axial connectors also include a three-lug arrangement to rule out an
accidental forced mating with a BNC connector. Adaptors exist to allow some
interconnection possibilities between tri-ax and BNC connectors.

[edit]
See also

BNC
inserter/remover tool

[edit]
References

Wikimedia
Commons has media related to: BNC

This article needs additional citations
for verification.
Please help improve this article by adding reliable
references. Unsourced material may be challenged and
removed. (May 2008)

^
Amphenol
Connex - BNC Connector specifications

^ Electrical connector. US Patent 2,540,012 by Octavio M.
Salati

^ Amphenol RF
- Twin BNC connector series

v • d • e

RF
connectors

N · BNC · TNC · F · SMA · SMB · SMC · TV Aerial
Plug · MMCX · MCX · FME · C · UHF · GR · Motorola · Musa · Mini-UHF · QMA/QN · APC-7 · EIA · Hirose
U.FL

v • d • e

Audio
and video connectors

Single conductor audio

Binding
post · Banana
plug · Fahnestock
clip

Analog audio

TRS ·
XLR ·
DIN /
Mini-DIN ·
D-sub ·
Speakon

Digital audio

BNC · S/PDIF ·
TosLink ·
XLR ·
D-sub

Video

DVI /
Mini-DVI /
Micro-DVI ·
DMS-59 ·
VGA /
Mini-VGA ·
DFP ·
BNC · DIN /
Mini-DIN ·
DB13W3 ·
D-Terminal

Audio and Video

RCA ·
ADC ·
Belling-Lee ·
DisplayPort /
Mini
DisplayPort · EVC ·
F ·
HDMI ·
P&D ·
AV
Multi · MultiAV ·
SCART ·
TRS

Visual charts

List of
video connectors

Retrieved from "http://en.wikipedia.org/wiki/BNC_connector"

Category: Coaxial
connectors

Hidden category: Articles
needing additional references from May 2008

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This page was last modified on 6 January 2009, at 21:19.

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