KRAMER ELECTRONICS LTD.
12
Noise bars are "rolling" up or
down in the output image
or:
Low Frequency Hum in the
output signal
Hum bars (ground loop) are caused by a difference in the ground potential
of any two or more devices connected to your signal path.
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
ground loop reappears. Disconnect the affected cable and replace, or
insert an isolation transformer in the signal path.
11.3
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.
