Kramer Electronics VS-5x4 user manual Audio Signal, Control, Problem

Problem

Noise bars “roll” up or down in the output image

or:

Low frequency hum in the output signal

Remedy

Hum bars (ground loop) are caused by a difference in the ground potential of any two or more devices connected to your signal path. This difference is compensated by passing that voltage difference through any available interconnection, including your video cables.

WARNING!

Do not disconnect the ground from any piece of video equipment in your signal path!

Check the following to remove hum bars:

1.Confirm that all interconnected equipment is connected to the same phase of power, if possible.

2.Remove equipment connected to that phase that may introduce noise, such as motors, generators, etc.

3.Disconnect all interconnect cables and reconnect them one at a time until the ground loop reappears. Disconnect the affected cable and replace, or insert an isolation transformer in the signal path.

16.3 Audio Signal
Problem	Remedy
No audio at the output	1.	Confirm that your sources and output device are turned on and
device, regardless of input		connected properly. Audio signals connected to the input of your
selected		switcher should be properly wired to the output of your source. Audio
		signals connected to output of your switcher should be properly wired
		to the input of your switcher or recorder.
	2.	Confirm that any other switchers in the signal path have the proper
		input and/or output selected.
Audio level is too low	1.	Confirm that the connecting cables are of high quality and properly
		built. Take special care in noting the wiring configuration of balanced
		to unbalanced cables.
	2.	Check level controls located on your source input device or output
		display or recorder.

16.4 Control

Problem	Remedy
No control of switcher	1.	Confirm the wiring of the connecting cable. Cable length should not
from PC software		exceed 25 feet.
	2.	Confirm that all DIP switches on the switcher have been set properly.
		Keep in mind that if you are only controlling one switcher on a
		specific port, that switcher must be assigned as unit “1”.
	3.	Confirm that the baud rate of your computer COM port is set to the
		same as that of your switcher (9600-Baud). Confirm that the proper
		COM port is selected in the control software.
	4.	Confirm that bi-directional communication is enabled on all
		switchers. With custom software, do not send multiple commands at
		the same time. The switcher must complete one command and send a
		reply before receiving another.
	5.	Make sure that all switchers are powered up. Communication between
		the machines can only be done when all machine are turned on.
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KRAMER Electronics, Ltd.