4.TWISTED PAIR INTERFACES AND KRAMER TOOLS
This manual includes information about configuration, operation, maintenance and optional accessories for the following Twisted Pair Interfaces and Kramer Tools (please note that machines from the same family have several features in common):
TP-1xl- Video Line Transmitter | TP-12xl - Video/Audio Line Receiver |
TP-2xl - Video Line Receiver | 704, 705 | - Video Line Transmitter/Receiver |
TP-6 - Twisted Pair Line Amplifier | 707, 708 | - Video/Audio Line Transmitter/Receiver |
TP-11N - Video/Audio Line Transmitter 709, 710 - Y/C Line Transmitter/Receiver
TP-12N - Video/Audio Line Receiver | 711(xl), 712(xl) - AV Line Transmitter/Receiver |
TP-11xl - Video/Audio Line Transmitter
5.A WORD ON BALANCED LINE TECHNOLOGY AND TWISTED PAIR INTERFACES
Video/Audio Balanced Line systems allow transmission of high quality (high signal/noise ratio) video and audio signals on low quality twisted-pair cables thanks to a procedure of noise reduction. The process principally consists of two main manipulative phases; in the first, the signal is electrically inverted in the transmitter. The inverted and non-inverted signals are then transmitted together on a twisted-pair line, accumulating noise along the way. At the receiver, the inverted signal is subtracted from the non-inverted one, resulting in a signal of twice the amplitude (A – (-A) = 2A). Since the two inverted signals pick up the same noise (with equal polarity) the subtraction eliminates the noise.
By using twisted-pair technology, simplification of studio and industrial wiring is easily achieved. The price of Twisted Pair wires is far lower than that of coaxial cables, so it is an attractive alternative for an extensive array of applications. Some of the twisted pair machines are fed by a 12VDC source, and are therefor suitable for fieldwork. The DC fed machines can power one another using a 4-wire setup.
The Twisted Pair interfaces are divided into three families as follows:
Twisted Pair Transmitters - Used to convert video and audio signals to a twisted-pair signal format (balanced line). Some of the machines convert only video, while some convert video and also two channels of audio to a single twisted-pair compatible signal, thus sparing the use of three coaxial cables. User- accessible trimmers are sometimes used for signal level and cable compensation.
Twisted Pair Receivers - Used to convert a twisted-pair format signal back to video and audio signals. Receivers having a looping capability allow receivers to be chained together. Some have a polarity switch, allowing the user to connect the wire using any polarity.
Twisted Pair Amplifiers - used to extend the operating distance of the twisted-pair system by adding amplification and cable compensation along the twisted-pair wire. Machines which feed the power via a 4- wire system eliminate the need to forward a power source to a remote location where the line amplifier is installed.
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