3Com CP-1 Two-Way Radio User Manual

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Problem Possible Cause and Solution
Muffled sound in L&R channels When no center channel is used, the rear-panel phantom button
must be pushed IN.
Center channel sound muffled The center channel amp may be connected to the subwoofer jack
on the CP-1 rear panel. Reconnect to Center Output jack.
Hum Finding and eliminating audio hum in a complex installation can
be a very frustrating task. Often, the easiest way to identify the
culprit is to systematically eliminate devices from the audio chain.
If Cable TV is connected to any equipment in the system, start by
unplugging the Cable completely, preferably right at the wall
jack. If this eliminates, or greatly reduces the hum, it's worth a call
to your Cable company. A quick fix, assuming your cable is round
75 wire, is to attach a 75-300 transformer to the end, then attach
a 300-75 transformer to that, so that the end is back to a round
75 wire. There are commercially-available antenna lead isola-
tors which may provide additional insulation from electrical
Balance control doesn't work
in Pro Logic or Stereo Logic If there is no center channel in the system, the center channel
output is routed to both the left and right main outputs. This
means the left speaker reproduces not only the left channel
information, but also the center channel information. If you set the
balance all the way over to the right, the left channel information
will be attenuated, but the center channel wll still be present at the
left speaker. In other words, it's supposed to work that way.
Panorama Calibrate isn't working Panorama is an interaural crosstalk cancellation program that
produces an anti-phase cancellation signal to the opposite
speaker. When the calibration mode is in LEFT ONLY, there is still
cancellation signal coming out of the right speaker. This is a
psychoacoustic phenomenon and LEFT ONLY means the calibra-
tion signal should appear to come only from the left (usually to the
left of the speaker.)
Interference with AM, FM,
TV or Cable TV The CP-1 does generate minimal amounts of RF energy and is in
compliance with FCC rules. If some interfering noise is noted,
move AM loop and FM "T" type antennas away from the CP-1 and
reorient them as necessary. Use shielded cable for FM and antenna
Erratic recall of programs Severe power surges or sags can confuse the CP-1 memory. To
correct, or if you simply want to start over, restore the factory
defaults with the procedure described at the end of this section.