025-9368H 203VI REPAIRWARNINGRepair and/or servicing of this equipment may only be performed by qualified personnelexperienced in telephone, radio communications systems or by qualified personnel at an approvedrepair facility.In case of installation difficulty, call Zetron for a Model 748 Applications Support Engineer. Pleasehave the serial number of the unit and/or the Zetron order number when you call.If a unit develops a fault in service and the unit needs to be returned, after consultation with a Zetronengineer, you must obtain an Authorzed Returns Number (ARN) before returning the unit. Pleasequote the ARN in any further correspondence.Zetron, Inc.28 Campbell Court, Campbell Road,Bramley, TADLEY, Basingstoke,Hants, U.K.RG26-5EGTel No: +44 (0) 1256 880663FAX No: +44 (0) 1256 880491MISCELLANEOUS SERVICE NOTES1. When the unit is reset or powered on, an automatic memory test will be executed. If greater than20 memory errors are detected in the user programming, the unit will reset all of the userdatabase to the default settings. Any user with bad checksum will be marked as such and can bedisplayed under System Statistics in the Diagnostic menu.2. If the audio does not sound correct, perform an audio sweep test by generating an audio signal onthe RF input of the repeater (of known deviation), and monitor the repeater output deviation. Theoutput deviation should be fairly flat from 300 to 2500 Hz.3. When using the internal noise detector for COR, if the COR polarity switch seems backward, theaudio input from the receiver may not have enough high frequency content (greater than 6 kHz)for the noise detector to operate. It is usually caused by low pass filtering of the discriminatoraudio signal. An alternate connection point must be found in the receiver which providesunfiltered audio, or a receiver generated COR signal must be connected.
