. Various 8200 Section 5 free download

File name 8200_Section_5.pdf

OPTIMOD-FM 8200 TROUBLESHOOTING 5-1 Section 5 Troubleshooting page contents 5-2 Problems and Possible Causes 5-2 RFI, Hum, Clicks, Or Buzzes 5-2 Poor Peak Modulation Control 5-2 Audible Distortion On-Air 5-3 Audible Noise on Air 5-4 Whistle on Air, Perhaps Only in Stereo Reception 5-4 Shrill, Harsh Sound 5-4 Dull Sound 5-5 System Will Not Pass Line-Up Tones at 100% Modulation 5-5 System Will Not Pass Emergency Broadcast System ("EBS" USA Standard) Tones at the Legally-Required Modulation Level 5-5 Interference from Stereo Into Subcarriers 5-6 19kHz Frequency Out-of-Tolerance 5-6 L-R (Stereo Difference Channel) Will Not Null With Monophonic Input 5-6 General Dissatisfaction With Subjective Sound Quality 5-7 Security Pascode Lost (When Unit is Locked Out) 5-8 Troubleshooting IC Opamps 5-8 Technical Support 5-9 Factory Service 5-9 Shipping Instructions CAUTION The installation and servicing instructions in this manual are for use by qualified personnel only. To avoid electric shock do not perform any servicing other than that contained in the Operating Instructions unless you are qualified to do so. Refer all servicing to qualified service personnel. 5-2 TROUBLESHOOTING OPTIMOD-FM 8200 page Problems and Possible Causes Always verify that the problem is not the source material being fed to the 8200, or in other parts of the system. RFI, Hum, Clicks, Or Buzzes A grounding problem is likely. Review the information on grounding on page 2-19. The 8200 has been designed with very substantial RFI suppression on its analog and digital input and output ports, and on the AC line input. It will almost always operate adjacent to high-powered transmitters without difficulty. In the most unusual circumstances, it may be necessary to reposition the unit to reduce RF interference, and/or to reposition its input and output cables to reduce RF pickup on their shields. Particularly if you are using a long run of coaxial cable between the 8200 and the exciter, a ground loop or other problem may inject noise into the exciter's composite input -- particularly if the exciter's input is u