SparkGap,E2 ................................. 4-8
Digital Modulation Principles ....................... 4-8
DigitalTermsandConcepts ...................... 4-8
Analog to Digital Conversion ..................... 4-9
RFAmplifierControl............................ 4-9
Amplitude Modulation in the DX-25U ............. 4-10
PowerAmplifierStage.......................... 4-10
Summary:DigitalModulator..................... 4-10
Section V
Maintenance/Alignments
Introduction ..................................... 5-1
Maintenance..................................... 5-1
Maintenance Logbook ........................... 5-1
PreventiveMaintenance.......................... 5-1
MaintenanceOfComponents ..................... 5-1
ModuleReplacement/Alignment..................... 5-3
Modules Which Can Be Replaced With No Adjust-
ments.......................................... 5-3
BufferAmplifier(A16).......................... 5-3
Predriver...................................... 5-3
PAModules................................... 5-3
RF Drive Splitter Removal ....................... 5-4
RF Drive Splitter Replacement .................... 5-4
Boards Which Require Preset Switch Settings or
JumperPlugPositions............................. 5-4
Modulation Encoder (A37) ....................... 5-4
ControllerA38................................. 5-5
Binary Combiner/Motherboard, Main Com-
biner/Motherboards(A5-A8)...................... 5-5
DriverCombiner/MotherboardA14 ................ 5-5
PrintedCircuitBoardsWhichRequireAdjustments ..... 5-5
Analog to Digital Converter (A34) ................. 5-6
AnalogInputBoard(A35)........................ 5-6
Oscillator(A17)................................ 5-7
DriverSupplyRegulator(A22).................... 5-8
DCRegulator(A30)............................. 5-8
OutputMonitor(A27)........................... 5-9
LEDBoard(A32).............................. 5-11
DriverEncoder/TempSenseBoard(A19) .......... 5-13
SwitchBoard/MeterPanel(A31) ................. 5-14
FrequencyChangeProcedure...................... 5-15
TestEquipmentRequiredforFrequencyChange..... 5-15
Frequency Determined Components ............... 5-15
FrequencyDeterminedJumpersandSwitches....... 5-15
OutputNetworkDryTune....................... 5-15
RFCircuitsCheckout........................... 5-16
InitialDriverTuningandSetup................... 5-17
InitialTuningAtLowPower..................... 5-18
TuningAtHighPower.......................... 5-19
Completion of Basic Frequency Change of Transmit-
ter.......................................... 5-19
OtherAdjustments............................. 5-20
Section VI
Troubleshooting
Introduction ..................................... 6-1
Symptom: Transmitter will not turn ON - No Color-
Stat™panelindicatorsareilluminated................ 6-6
PossibleCauses ................................ 6-6
Symptom: Transmitter will not turn on - all Color-
Stat™panelindicatorsareilluminatedGreen........... 6-6
PossibleCauses................................. 6-6
Symptom: Transmitter will not turn on - one or more
ColorStat™ panel indicators are illuminated RED. ...... 6-7
PossibleCauses................................. 6-7
Symptom: Transmitter will turn ON but immediately
turns OFF - one or more ColorStat™ panel indica-
tors illuminate RED. The transmitter may try to turn
on twice and a fault indicator illuminates AMBER
thenRED. ...................................... 6-7
PossibleCauses................................. 6-7
Symptom: Transmitter turns On (LOW, MEDIUM or
HIGH buttons illuminate) but there is no power out-
put and no PA current is indicated. Supply voltage is
indicated on the multimeter. ........................ 6-7
PossibleCauses................................. 6-7
Symptom: Transmitter is running, but power is lower
thannormal...................................... 6-7
PossibleCauses................................. 6-7
Symptom: Unable to raise power past a certain point.
ColorStat™ panel ANT and/or FILTER LED indi-
cateRED........................................ 6-8
Possiblecause.................................. 6-8
Symptom: Unable to raise power past a certain point.
NoColorStat™panelindicatorsIlluminatedRED....... 6-8
Possiblecause.................................. 6-8
Symptom: Transmitter turns ON (Low, Medium, or
HighIndicatorsIlluminate)butwillnotmodulate....... 6-8
PossibleCauses................................. 6-8
ColorStat™panelOvercurrentFaultIndication......... 6-8
Random Faults With Program Audio. Possible
Causes:....................................... 6-8
Faults With Tone Modulation. Possible Causes:....... 6-9
OverloadsonTurnOn.PossibleCauses:............. 6-9
ColorStat™panelOvervoltageFault.................. 6-9
PossibleCauses................................. 6-9
ColorStat™panelSupplyFault.....................6-10
PossibleCauses................................ 6-10
ColorStat™panelUnderdriveFault ................. 6-10
PossibleCauses................................ 6-10
ColorStat™panelOverdriveFault................... 6-11
PossibleCauses................................ 6-11
ColorStat™panelDoorInterlock ................... 6-12
PossibleCauses................................ 6-12
ColorStat™panelExternalInterlock................. 6-12
PossibleCauses................................ 6-12
ColorStat™panelAirInterlock..................... 6-12
Possiblecauses................................ 6-12
ColorStat™panelOscillatorFault................... 6-12
ColorStat™panelBufferFault ..................... 6-13
ColorStat™panelPredriverFault................... 6-13
ColorStat™panelRFAmpFault.................... 6-13
ColorStat™ panel Analog Input Board: +15V and -
15VSupplyFaults............................... 6-13
ColorStat™ panel Analog to Digital Converter ........ 6-13
+15V, -15V, and +5V Supply Faults...............6-13
ConversionErrorFault.......................... 6-13
ColorStat™ panel Modulation Encoder: Cable Inter-
lockFault...................................... 6-13
8/9/2000 888-2297-002 v
WARNING: Disconnect primary power prior to servicing.
To Next Page
Loading...
