OPTIMOD-FM TROUBLESHOOTING
5-7
System Receiving 8400’s Digital Output Will Not Lock
Be sure that the 8400’s output sample rate is set match the sample rate that the driven
system expects. Be sure that the 8400’s output mode (AES/EBU or SPDIF) is set to
match the standard expected by the driven system.
19 kHz Frequency Out-of-Tolerance
First, verify that a problem really exists by using a second frequency measuring device
and/or verifying the problem with your monitoring service. If the problem is real, contact
Orban Customer Service for a crystal replacement; there is no frequency trim available.
L–R (Stereo Difference Channel) Will Not Null With Monophonic Input
This problem is often caused by relative phase shifts between the left and right channels
prior to the 8400’s input. This will cause innocuous linear crosstalk between the stereo
main and subchannels. Such crosstalk does not cause subjective quality problems unless
it is very severe.
General Dissatisfaction with Subjective Sound Quality
The 8400 is a complex processor that can be adjusted for many different tastes. For most
users, the factory presets, as augmented by the gamut offered by the
Less-More control
for each preset, are sufficient to find a satisfactory “sound.” However, some users will
not be satisfied until they have accessed other Modify Processing controls and have ad-
justed the subjective setup controls in detail to their satisfaction. Such users must fully
understand the material in Section 3 of this manual to achieve the best results from this
exercise.
By comparison to competitive processors, the 8400 offers a uniquely favorable set of
trade-offs between loudness, brightness, distortion, and build-up of program density. If
your radio station does not seem to be competitive with others in your market, the cause
is usually source material (including excess use of lossy digital compression), overshoot
in the transmission link (including the FM exciter) following the 8400, or an inaccurate
modulation monitor that is causing you to under-modulate the carrier. A station may suf-
fer from any combination of these problems, and they can have a remarkable effect on the
overall competitiveness of a station’s sound.
Section 1 of this manual provides a thorough discussion of system engineering considera-
tions, particularly with regard to minimizing overshoot and noise.
Security Passcode Lost (When Unit is Locked Out)
Please see If you have forgotten your “All Screens” passcode… on page 2-45.
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