KRAMER ELECTRONICS, LTD.
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INTRODUCTION
Congratulations on your purchase of a Kramer Electronics RGBHV/ Balanced Stereo Audio Matrix Switcher.
Since 1981 Kramer has been dedicated to the development and manufacture of high quality video/audio
equipment. The Kramer line has become an integral part of many of the best production and presentation
facilities around the world. In recent years, Kramer has redesigned and upgraded most of its line, making the
best even better. Kramer’s line of professional video/audio electronics is one of the most versatile and complete
available, and is a true leader in terms of quality, workmanship, price/performance ratio and innovation. In
addition to the Kramer line of high quality matrix switchers, such as the one you have just purchased, Kramer
also offers a full line of high quality distribution amplifiers, processors, interfaces, controllers and computer-
related products. This manual includes configuration, operation and option information of the following
RGBHV/ Balanced Stereo Audio Matrix Switchers. These VP series matrix switchers are similar in operation
and features:
VP-88
: 8x8 RGBHV/ Balanced Stereo Audio Matrix
VP-84
: 8x4 RGBHV/ Balanced Stereo Audio Matrix
VP-82
: 8x2 RGBHV/ Balanced Stereo Audio Matrix
VP-66
: 6x6 RGBHV/ Balanced Stereo Audio Matrix
VP-64
: 6x4 RGBHV/ Balanced Stereo Audio Matrix
1.1
A Word on Video/Audio Switchers
A video/audio switcher switches between several sources (inputs) and one or more acceptors (outputs). A
switcher that allows several inputs to be connected to several outputs simultaneously is called a matrix switcher.
Switchers may be of the electronic or mechanical type. Most matrices are of the active electronic type, with
many crosspoints. Vertical Interval Switching, frequently used in video, ensures that the transition from one
video source to another (such as switching between two genlocked cameras) is smooth and without interference.
The switching and changeover is done during the blanked vertical interval period, when the transition is hidden
from the eyes. Vertical Interval Switching is needed when recording or transmitting a video program involving
several video sources, as in live broadcast, to ensure clean, undisturbed picture transitions. The switched sources
should be genlocked. Matrices and switchers are sometimes RS-232 or RS-485/422 controlled. Each of these
options is a way of remotely controlling a video/audio device (switcher, etc.) using a PC with a serial port, or
another device that uses a similar communication protocol. The simplest connection between the RS-232
controller and the controlled device uses two wires (TRANSMIT, RECEIVE) and a common ground wire.
Finally, the wide video bandwidth permits the matrix switchers to be used in the most demanding applications.
1.2
Factors Affecting Quality of Results
There are many factors affecting the quality of results when signals are transmitted from a source to an acceptor:
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Connection cables
- Low quality cables are susceptible to interference, they degrade signal quality due
to poor matching and cause elevated noise levels. They should therefore be of the best quality.
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Sockets and connectors of the sources and acceptors
- So often ignored, they should be of highest
quality, since "Zero Ohm" connection resistance is the target. Sockets and connectors also must match
the required impedance (75ohm in video). Cheap, low quality connectors tend to rust, thus causing
breaks in the signal path.
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Amplifying circuitry
- Must have quality performance when the desired end result is high linearity, low
distortion and low noise operation.
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Distance between sources and acceptors
- Plays a major role in the final result. For long distances
(over 15 meters) between sources and acceptors, special measures should be taken in order to avoid cable
losses. These include using higher quality cables or adding line amplifiers.
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Interference from neighboring electrical appliances
- These can have an adverse effect on signal
quality. Balanced audio lines are less prone to interference, but unbalanced audio should be installed far
from any mains power cables, electric motors, transmitters, etc. even when the cables are shielded.
