System Will Not Pass Line-Up Tones At 100% Modulation; System Will Not Pass Emergency Alert System ("Eas" Usa Standard) Tones At The Legally Required Modulation Level; System Receiving 5500'S Digital Output Will Not Lock; 19 Khz Frequency Out-Of-Tolerance - Orban OPTIMOD-FM 5500 Operation Manual

5-6
TROUBLESHOOTING

System Will Not Pass Line-Up Tones at 100% Modulation

System Will Not Pass Emergency Alert System ("EAS" USA Standard) Tones at the
Legally Required Modulation Level

System Receiving 5500's Digital Output Will Not Lock

19 kHz Frequency Out-of-Tolerance

L–R (Stereo Difference Channel) Will Not Null With Monophonic Input

General Dissatisfaction with Subjective Sound Quality

This is normal. Sine waves have a very low peak-to-average ratio by comparison to
program material. The processing thus automatically reduces their peak level to
bring their average level closer to program material, promoting a more consistent
and well-balanced sound quality.
The 5500 can generate test tones itself. The 5500 can also be put into Bypass mode
(locally or by remote control) to enable it to pass externally generated tones at any
desired level. (See Test Modes on page 3-53.)
See System Will Not Pass Line-Up Tones at 100% Modulation (directly above) for an
explanation. These tones should be injected into the transmitter after the 5500, or
the 5500 should be temporarily switched to
Be sure that the 5500's output sample rate is set match the sample rate that the
driven system expects. Be sure that the 5500's output FORMAT (AES3 or SPDIF) is set
to match the standard expected by the driven system.
First, verify that a problem really exists by using a second frequency-measuring de-
vice and/or verifying the problem with a monitoring service. If the problem is real,
contact Orban Customer Service for a crystal replacement; there is no frequency trim
available.
This problem is often caused by relative phase shifts between the left and right
channels prior to the 5500'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.
The 5500 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 L
M control for each preset, are sufficient to find a satisfactory "sound." However,
ORE
some users will not be satisfied until they have accessed other Modify Processing
controls and have adjusted the subjective setup controls in detail to their satisfac-
tion. 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 5500 offers a uniquely favorable set of
trade-offs between loudness, brightness, distortion, and build-up of program den-
sity. If your radio station does not seem to be competitive with others in your mar-
ket, the cause is usually source material (including excess use of lossy digital com-
pression), overshoot in the transmission link (including the FM exciter) following the
5500, or an inaccurate modulation monitor that is causing you to under-modulate
the carrier. A station may suffer from any combination of these problems, and they
can have a remarkable effect on the overall competitiveness of a station's sound.
to pass the tones.
BYPASS
ORBAN MODEL 5500
-
ESS