Nautel V10 User's Installation And Operation Manual

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Nautel V10 User's Installation And Operation Manual Manual pdf 113 page image

V10/V7.5/V5/V3.5 Installation and Operation Manual Page 5-9Section 5 System Level Troubleshooting Issue 3.5• reaching an acceptable level, butcontinually dropping to 0 W, seeparagraph 5.5.1.1.2 'Exciter OutputLoad Fluctuation'.• stable and within acceptable limits[above 12 W (6 W) for analogconfigured V10/V7.5 (V5/V3.5) or 6 W(3 W) for digitally configured V10/V7.5(V5/V3.5) and below 38 W forV10/V7.5 or 19 W for V5/V3.5 in FMmode], the problem may be the RFdrive monitor protection circuitry on thecontrol/display PWB (A43) or adefective component on the RF drivesplitter/changeover PWB (A16A1). Indual exciter transmitters, if achangeover occurred and the reserveexciter is operating without alarm, thenthe problem must be exciter related.Refer to the associated exciter’smanual.NOTEIf it is necessary to check the control/display PWB's (A43) RF drive monitorcircuitry, refer to the Repair manual toisolate circuit defects.5.5.1.1.1 Low RF DriveThe exciter power has fallen below the lowRF drive threshold. Increase the exciteroutput power until it reaches 20 W (10 W)for analog configured V10/V7.5 (V5/V3.5)transmitters or 10 W (5 W) for digitallyconfigured V10/V7.5 (V5/V3.5) transmittersoperating in FM mode.5.5.1.1.2 Exciter Output LoadFluctuationA problem may exist with the RF drivesplitter/changeover PWB (A16A1). If noproblem is found with the RF drive splitter/changeover PWB, the problem is likelyexciter related. Refer to the exciter’smanual for further troubleshootinginformation.Possible Associated Faults:- IPA Input Pwr Low5.5.1.2 IPA Input HighAn IPA Input Pwr High alarm, althoughunlikely, occurs if the input RF drive(exciter power) to the active IPA moduleexceeds the high RF drive threshold [IPAInput High threshold is user definable, butis defaulted to 38 W for V10/V7.5 or 19 Wfor V5/V3.5 in FM mode; the threshold is25 W for V10/V7.5 and 13 W for V5/V3.5in FM+HD or HD mode]. This alarmoccurs if ALC cannot respond fast enoughto varying exciter load changes, or if ALCis disabled, or if the exciter’s output hasincreased to a very high level.• Verify ALC is enabled on the exciter.• Compare the exciter’s programmedlevel to its actual output. If there is asignificant difference, an exciterregulation problem may exist. Refer tothe exciter’s manual.NOTEThe control/display PWB's (A43) RF drivemonitor circuitry generates an exciterinterlock control signal to mute the exciter'sRF output for a predetermined delay. Thissignal is generated each time the exciter'soutput exceeds its high power threshold.Possible Associated Faults:- IPA Input Pwr High5.5.1.3 Exciter Communication FailureAn Exciter Comm Fail alarm occurswhen communication between thetransmitter and exciter has failed (M50exciter only). Troubleshoot an ExciterComm Fail alarm as follows:NOTEDuring an Exciter Comm Fail faultcondition, the Check Exciter and ExciterFault alarms (see paragraphs 5.5.1.4 and5.5.1.5) are disabled and will never bedisplayed by the transmitter, as thesealarms depend upon communication withthe M50 exciter.