HP TM 11-6625-2779-14&P manual Delete CR6 across M1, Government Printing Office 1980-603-128/66

Page 80

Appendix C

Model 3555B

Change part no. of the case assembly to 03555-04505.

Change cover part no. to 03555-04504.

Table 6-1.

Change the part no. of the power cord to 81 20-0249.

Change the part no. of the power connector J1 to 1251-0148.

Change No. 5

Table 6-1.Change to the following gray parts:

Cover, battery	00236-04104
Bracket, meter	00741-0 1209
Panel, front	03555-00203
Assy. cover	03555-64504
Assy. case	03555-64506
Knob, pushbutton	0370-0440

Change No. 6

Page 6-7.Change C2 to 0180-0110, 8 μF

Delete CR2 -4 1901-0025.

Page 6-8.Change T1 part no. to 9100-1457.

Figure 7-5.Delete CR2 -4 from the Power Supply Rectifier.

Change No. 7

Page 6-7.Delete CR6, 1901-0040.

Figure 7-5.Delete CR6 across M1.

*U.S. GOVERNMENT PRINTING OFFICE: 1980-603-128/66

C-2

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Contents HEADQUARTERS, Department of the Army Reporting Errors and Recommending Improvements TM 11-6625-2779-14&PTechnical Manual Headquarters Department of the Army NSNReplaceable Parts Iii List of IllustrationsList of Tables Scope Maintenance Forms, Records, and ReportsSection Introduction Reporting Equipment Improvement Recommendations EIR Administrative StorageDestruction of Army Electronics Materiel Items Comprising an Operable Equipment Specifications Voice Frequency Level Measurements 20Hz to 20kHzSection Section General Information IntroductionAccessory Equipment Supplied Accessory Equipment SuppliedInstrument Identification BAL ModificationSection Installation Inspection Warranty ExceptionPower Requirements BatteryInstallation and Removal of Battery Cover RemovalControls Connectors Indicators BatterySection Operating InstructionsFront Panel Controls, Indicators, and Connectors Front, Side and Rear Pane Side Panel Controls and Connectors Level and Noise Measurements Level MeasurementsPage Noise Measurement Recorder Compatibility ApplicationsRecorder Compatibility Chart Identifying Noise Characteristics Transmission Loss MeasurementsCrosstalk Measurements Crosstalk Correction FactorMeasurements in DBC Reinstall the set in its case 0dBmInput jacks are connected in parallel. If a 600 ohm 135 BALStep Procedure Level Measurement Noise Metallic MeasurementsNoise-to-Ground Measurements Balance Measurement Recorder CalibrationExample Transmission Loss MeasurementBlock Diagram Description Section Theory of Operation IntroductionDetailed Circuit Description Simplified Dial BAT FunctionInput Amplifier A3. Schematic No Range Attenuator A2Setting Attenuation FILTERS. Schematic NoRange Attenuator Pads UsedKHz Flat and Program Weighting Curves C-MSG and 1SkHz Flat Weighting Curves Meter AMPLIFIER. Schematic No DETECTOR. Schematic NoPower Supply and Series Regulator Schematic No Section Maintenance Introouction Instrument Recommended Type Required Characteristics ModelFactory Selected Values BAL ConversionPerformance Checks Level Accuracy ChecksFunction CARRIER, 75 Unbal TMS, TermUnbal Carrier Accuracy Check RangeFrequency 30Hz to 1MHz 100Hz to 600kHz 1MHz to 3MHzReturn Loss Check 20Hz to 20kHz 40Hz to 15kHz 100Hz to 20kHz 100Hz to 15kHzReturn Loss Test Set-Up MSG dBm 3kHz Flat dBm 15kHz Flat dBm Program dBm Filter Response ChecksFilter Response Checks Input Balance Bridging LossTMS Brdg Input TMS BrdgAdjustment and Calibration Procedure Power Supply CheckUnbal Calibration Attenuator CalibrationBalance Check Frequency Response AdjustmentCommon Mode Adjustment Filter Calibration Assembly RemovalTroubleshooting Procedures Troubleshooting Tree Front Panel Trouble Analysis Dial BATFront Panel Troubleshooting Function TroubleshootingRange Troubleshooting Front Panel Trouble Analysis ContdTroubleshooting Input Amplifier Filter TroubleshootingTroubleshooting the Meter Amplifier and Detector Defective FunctionFunction Switch Resistance Values Function Input Jacks DIAL/AC MON JacksTip to Ring Tip to Ground Ring to Ground Brdg TermRange dBm Pin 1 to Pin 2 to 11. Factory Selected Values10. Resistance Checks Performance Check Test Card Description CheckCarrier 75 Unbal Level Accuracy Check Carrier 135 BAL Level Accuracy CheckPerformance Check Test Card Contd Carrier 600 BAL Level Accuracy CheckReturn Loss Check Filter Response Checks MSGProgram Bridging Loss CheckSection Replaceable Parts Introduction Ordering InformationReplaceable Parts 03555-66507 PC Board Assy functionReplaceable Parts Contd 03555-66508 Board Assy amplifierA3 Contd 03555-66506 PC Board Assy filter A4 Contd Chassis Mounted Components Chassis Mounted Components Contd MiscellaneousMiscellaneous Contd Replacement National Part Stock Number Fscm Part Number National Stock Number Cross Reference IndexFscm National Stock NumberPage Model 3555B Appendix a Code List of Manufacturers Circuit Diagrams Functional Block DiagramSchematic Diagrams Reference DesignationsSection Model 3555B Functional Block Diagram 7-4A1 Function Assembly Schematic and Component Location 7-67-8 A4 Filter Schematic and Component Location 7-1011/7-12 Appendix a ReferencesMaintenance Allocation Section I. Introduction General Maintenance FunctionAppendix B Column EntriesTool and Test Equipment Requiremen ts Sec Remarks SecAudio Level Meter TA-885/U TM 11-7725-2779-14&P REF Code NumberTransmission and Noise Measuring SET Appendix CManual Backdating Changes Delete CR6 across M1 Government Printing Office 1980-603-128/66General, United States Army Chief of StaffMajor General, United States Army Adjutant General Active ArmyPage PIN