J

Asphalted jute, nonmetallic armor.

Jack

A receptacle or socket that accepts the plug on telephone instruments and associated equipment in the telecommunications industry.

Jack Retainer

A device that acts as a jack to terminate cable and mates with a plug within a telecom's receptacle housing.

Jack-and-Plug

A small pin-count input/output electronic interconnect device.

Jacket

Outermost layer of insulating material of a cable or wire.

Jackscrew

A screw attached to one-half of a two-piece, multiple-contact connector and used to draw both halves together and to separate them.

JAN

Joint Army-Navy

JEDEC

Joint Electronic Device Engineering Council. An international organization that sets standards for integrated circuits.

JEIDA

Japan Electronic Industry Development Association. A standards organization in Japan. Prominent members include Hitachi, Maxell, Matsushita, Seiko-Epson, Toshiba, and Fujitsu.

JFET

Junction Field Effort Transistor

JIS

Japan Institute of Standards. The national standards body in Japan. Similar to ANSI in the U.S. and DIN and ISO in Europe.

Joint

The connecting point of two conductors.

Jump

See Jumper.

Jumper

An interconnect device used to turn circuits on and off. Jumpers have no moving parts and cannot be accidentally reprogrammed. Also called a shunt.

Jumper Cable

1. A short piece of wire (or wire with pre-terminated connectors) used to cross-connect elements of a wiring system.
2. A short, flat cable that interconnects two printed wiring boards or devices.

Also called a patch cable.

Junction

1. Optical interface.
2. A joining of two different semi-conductors or semi-conductor and metal.

Junction Temperature

Temperature at a terminal and stud post.