Fiber Optic Patch cord
A patch cable or patch cord or patch lead is an electrical
or optical cable used to connect ("patch-in") one electronic or
optical device to another for signal routing. Devices of different types (e.g.,
a switch connected to a computer, or a switch to a router) are connected with
patch cords. Patch cords are usually produced in many different colors so as to
be easily distinguishable, and are relatively short, perhaps no longer than two
metres. Types of patch cords include microphone cables, headphone extension
cables, XLR connector, Tiny Telephone (TT) connector, RCA connector and ¼"
TRS phone connector cables (as well as modular Ethernet cables), and thicker,
hose-like cords (snake cable) used to carry video or amplified signals.
However, patch cords typically refer only to short cords used with patch
panels.
Patch cords can be as short as 3 inches (ca. 8 cm), to
connect stacked components or route signals through a patch bay, or as long as
twenty feet (ca. 6 m) or more in length for snake cables. As length increases,
the cables are usually thicker and/or made with more shielding, to prevent
signal loss (attenuation) and the introduction of unwanted radio frequencies
and hum (electromagnetic interference).