Nautel V10 User's Installation And Operation Manual

Contents

Nautel V10 User's Installation And Operation Manual Manual pdf 132 page image

Page 5-28 V10/V7.5/V5/V3.5 Installation and Operation ManualIssue 3.5 Section 5 System Level Troubleshooting5.8 RF POWER MODULE FAULTISOLATIONTo determine if an RF power module isdefective and then which RF powermodule(s) caused the alarm condition to begenerated, perform the following:NOTEA defective RF power module can beremoved while the transmitter is on-air (see5.9). The transmitter will resume operationat a reduced output power level with theRF power module removed, provided therequirements of paragraph 5.7 are met.(a) Verify the IPA/PA lamp on the frontpanel’s system diagram is turned on(red). A reduction in forward powershould also be detected.(b) Using the GUI’s Status screen,determine which RF power module hasfailed by noting the indicated RF powermodule(s) (A-H for V10, A-C, E-G forV7.5, A-D for V5 or A-C for V3.5).Note the red PA FAIL lamp(s) on theaffected RF power module should alsobe on. If the associated power supplyis inhibited, the power supply’s red DCFAIL lamps will be on and the RFpower module’s PA FAIL and PA VDC(amber) lamps will be off.(c) As a troubleshooting aid, monitor thesuspect module’s parameters [DCCurrent (Q1-Q4), Bias, PA Voltage,Temperature, Int. RF Drive Level, FanSpeed] from the Module Statusscreen to see which is out-of-toleranceor indicating a failure.NOTEThe left-hand column of the transmittercontains - from top to bottom - RF powermodules A-D (V10/V5) or A-C (V7.5/V3.5)and the IPA module (IPA module A forV10/V7.5). In V10/V7.5 transmitters, theright-hand column contains - from top tobottom - RF power modules E-H (V10) orE-G (V7.5) and IPA module B, ifapplicable.5.9 REPLACING AN RF POWERMODULEReplace an RF power module as follows:WARNINGTo prevent burns, use extreme care whenhandling RF power modules. The RFpower module exterior can reachtemperatures as high as 100°C before athermal trip occurs.CAUTIONRF power modules contain solid statedevices that may be damaged if subjectedto excessive heat or high voltagetransients. Ensure circuits are notoverdriven or disconnected from their loadswhile turned on.5.9.1 RF Power Module RemovalRemove a defective RF power modulefrom the transmitter as follows:(a) Verify the requirements of paragraph5.8 have been completed.(b) Set the switching power supply modulethat applies PA voltage to the RFpower module being removed toSTANDBY (toggle down). Theswitching power supply module’s redDC FAIL lamp should be on and theRF power module’s amber PA VDClamp should be off.(c) If necessary, remove the appropriatemodule packing bracket (see Figure2-6) to gain access to the defective RFpower module. Carefully withdraw theRF power module from its support trayat the front of the transmitter cabinet.NOTEIf an operational RF power module isavailable, it may be installed in thetransmitter while the defective powermodule is being serviced. Refer toparagraph 5.9.2 to install an RF powermodule. Refer to the Repair manual totroubleshoot and/or repair a defective RFpower module.