Kramer Electronics FC-10 - Manual (Page 24)

Kramer Electronics Ltd.
21
Video Signal (continued)
Problem Remedy
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. 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 ground loop reappears. Disconnect the affected cable and
replace, or insert an isolation transformer in the signal path.
12.3 Audio Signal (FC-4208 only)
Problem Remedy
No audio at the output
device, regardless of
input selected 1. Confirm that your source and output devices are powered and
properly connected. 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 devices in the signal path has 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.