A four-wire terminating set (4WTS) is a balanced transformer used to perform a conversion between four-wire and two-wire operation in telecommunication systems.
For example, a 4-wire circuit may, by means of a 4-wire terminating set, be connected to a 2-wire telephone set. Also, a pair of 4-wire terminating sets may be used to introduce an intermediate 4-wire circuit into a 2-wire circuit, in which loop repeaters may be situated to amplify signals in each direction without positive feedback and oscillation.
The 4WTS differs from a simple hybrid coil in being equipped to adjust its impedance to maximize return loss.
Four-wire terminating sets were largely supplanted by resistance hybrids in the late 20th century.
Famous quotes containing the words terminating and/or set:
“For, rightly, every man is a channel through which heaven floweth, and, whilst I fancied I was criticising him, I was censuring or rather terminating my own soul.”
—Ralph Waldo Emerson (1803–1882)
“Please do not take counsel of women who are so prejudiced that, as I once heard said, they would not allow a male grasshopper to chirp on their lawn; but out of your own great heart, refuse to set an example to such folly.”
—Frances E. Willard (1839–1898)