J2 - Wide-area
digital transmission scheme used predominantly in Japan that carries data at a
rate of 6.312 Mbps.
Jitter - Analog
communication line distortion caused by variations of a signal from its
reference timing position.
JPEG (Joint Photographic
Experts Group) - An ISO Standards group that defines how to compress
Juice - Slang for
electric current or power.
Jumper - A patch
cable or wire used to establish a circuit, often temporarily, for testing or
diagnostics; also, the devices, shorting blocks, used to connect adjacent
exposed pins on a printed circuit board that control the functionality of the
Junction Box - Box
inside which low-voltage power cable joints are made.