What Is a Coaxial Bulkhead Fitting?
A bulkhead fitting is an evolution of the ubiquitous coaxial connectors perhaps most familiar as the connectors used to attach antennas, or more recently cable services, to the rear of television sets. Said connectors are typically of the SubMiniature version A type, universally referred to by the acronym SMA. Bulkhead fittings are SMA fittings adapted for attachment to bulkheads. Does this Spark an idea?
-
SubMiniature Version A Connectors
-
SMAs are coaxial cable connectors. In use since the 1960s, SMA connectors give such excellent conductive performance that they have remained in favor with designers and users as technology has progressed into vehicle tracking systems, wireless local area network computer systems and numerous other applications. SMA connectors use a 1/4-inch, 36-thread-rated coupling and an 8 millimeter hex nut. Among numerous configurations, SMA connectors are manufactured as bulkhead fittings.
Distinguishing Features
-
What distinguishes a bulkhead fitting from a regular SMA connector is thread length and the inclusion of a washer nut in its design. Any SMA connector fitted with a washer nut and having a thread-length greater than approximately 4.5 millimeters is a bulkhead fitting. The extended thread length allows the fitting to be passed through a barrier -- the eponymous “bulkhead” -- such as the housing of a television set or a multi-connector panel. The nut then allows it to be secured in place without the need for any additional hardware.
-
Configurations
-
Bulkhead fittings are available in two configurations: rear-mount and front-mount. Rear-mount bulkhead fittings are designed so that the thread passes through the bulkhead from inside -- the component side -- to outside the bulkhead, and the washer nut is secured in place on the outside. Front-mount bulkhead fittings are designed so that the thread passes through the bulkhead from outside to inside the bulkhead, and the washer nut is secured in place on the inside.
Series Configurations
-
A “within series” coaxial adapter is a connector used to join interfaces of the same series, typically joining an SMA connector to another SMA connector. A “between series” adapter is a connector used to join interfaces of different series, for instance joining an SMA connector to the less common Bayonet Neill-Concelman format. Both within series and between series connectors are available in male-to-female, male-to-male and female-to-female configurations. Bulkhead fittings are available in both within and between series configurations.
-
References
- Photo Credit Hemera Technologies/PhotoObjects.net/Getty Images
