KRAMER ELECTRONICS, LTD.
13
Problem
Remedy
Noise bars "roll" up or
down in the output image
or:
Low Frequency Hum in the
audio output
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.
Audio Signal
Problem
Remedy
No audio at the output
device, regardless of input
selected
1.
Confirm that your sources and output device are turned on and connected
properly. Audio signals connected to the input of your machine should be
properly wired to the output of your source. Audio signals connected to the
output of your machine should be properly wired to the input of your machine
or recorder.
2.
Confirm that any other amplifiers in the signal path have the proper input
and/or output selected. Pay special attention to input amplifiers that may be
built into your acceptor.
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.
