TM 11-7725-2779-14&P, REF Code Number | HP TM 11-6625-2779-14&P

TM 11-7725-2779-14&P

SECTION III. TOOL AND TEST EQUIPMENT REQUIREMENTS

FOR

AUDIO LEVEL METER TA-885/U

TOOL OR
TEST	MAINTENANCE		NATIONAL/	TOOL
EQUIPMENT	CATEGORY	NOMENCLATURE	NATO STOCK	NUMBER
REF CODE			NUMBER
1	H,D	OSCILLATOR SG-1128/U, HP #654A	6625-00-450-7590
2	H,D	OSCILLATOR AN/URM-127	6625-00-783-5965
3	H,D	TRANSFORMER (LINE MATCHING) MX-8385/U	6625-00-567-5837
4	H,D	MULTIMETER AN/USM-451	6625-01-060-6804
5	H,D	AMPLIFIER HP-467A	6625-00-458-2480
6	H,D	VOLTMETER, ELECTRONIC ME-30 E/U	6625-00-643-1670
7	O	COMMON TOOLS NECESSARY TO THE PERFORMANCE OF
		THIS MAINTENANCE FUNCTION ARE AVAILABLE TO
		MAINTENANCE PERSONNEL FOR THE MAINTENANCE
		CATEGORY LISTED.

B-4

Image 78

HP TM 11-6625-2779-14&P manual TM 11-7725-2779-14&P, REF Code Number

Contents

HEADQUARTERS, Department of the Army Technical Manual Headquarters Department of the Army Reporting Errors and Recommending ImprovementsTM 11-6625-2779-14&P NSN Replaceable Parts List of Illustrations List of TablesIii Maintenance Forms, Records, and Reports Section IntroductionScope Administrative Storage Destruction of Army Electronics MaterielReporting Equipment Improvement Recommendations EIR Items Comprising an Operable Equipment Specifications Voice Frequency Level Measurements 20Hz to 20kHz Section Section General Information Introduction Instrument Identification Accessory Equipment SuppliedAccessory Equipment Supplied BAL Modification Power Requirements Section Installation InspectionWarranty Exception Battery Installation and Removal of Battery Cover Removal Section Controls Connectors IndicatorsBattery Operating Instructions Front 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 Applications Recorder Compatibility Chart Crosstalk Measurements Identifying Noise CharacteristicsTransmission Loss Measurements Crosstalk Correction Factor Measurements in DBC Input jacks are connected in parallel. If a 600 ohm Reinstall the set in its case0dBm 135 BAL Step Procedure Level Measurement Noise Metallic Measurements Example Noise-to-Ground Measurements Balance MeasurementRecorder Calibration Transmission Loss Measurement Block Diagram Description Section Theory of Operation Introduction Detailed Circuit Description Simplified Dial BAT Function Input Amplifier A3. Schematic No Range Attenuator A2 Range Attenuator Setting AttenuationFILTERS. Schematic No Pads Used KHz Flat and Program Weighting Curves C-MSG and 1SkHz Flat Weighting Curves Meter AMPLIFIER. Schematic No DETECTOR. Schematic No Power Supply and Series Regulator Schematic No Factory Selected Values Section Maintenance IntroouctionInstrument Recommended Type Required Characteristics Model BAL Conversion Function CARRIER, 75 Unbal Performance ChecksLevel Accuracy Checks TMS, Term Frequency Unbal Carrier Accuracy CheckRange 30Hz to 1MHz 100Hz to 600kHz 1MHz to 3MHz Return Loss Check 20Hz to 20kHz 40Hz to 15kHz 100Hz to 20kHz 100Hz to 15kHz Return Loss Test Set-Up Filter Response Checks Filter Response ChecksMSG dBm 3kHz Flat dBm 15kHz Flat dBm Program dBm TMS Brdg Input BalanceBridging Loss Input TMS Brdg Unbal Calibration Adjustment and Calibration ProcedurePower Supply Check Attenuator Calibration Frequency Response Adjustment Common Mode AdjustmentBalance Check Assembly Removal Troubleshooting ProceduresFilter Calibration Troubleshooting Tree Front Panel Trouble Analysis Dial BAT Range Troubleshooting Front Panel TroubleshootingFunction Troubleshooting Front Panel Trouble Analysis Contd Troubleshooting the Meter Amplifier and Detector Troubleshooting Input AmplifierFilter Troubleshooting Defective Function Tip to Ring Tip to Ground Ring to Ground Function Switch Resistance ValuesFunction Input Jacks DIAL/AC MON Jacks Brdg Term 11. Factory Selected Values 10. Resistance ChecksRange dBm Pin 1 to Pin 2 to Carrier 75 Unbal Level Accuracy Check Performance Check Test CardDescription Check Carrier 135 BAL Level Accuracy Check Performance Check Test Card Contd Carrier 600 BAL Level Accuracy Check Program Return Loss CheckFilter Response Checks MSG Bridging Loss Check Section Replaceable Parts Introduction Ordering Information Replaceable Parts 03555-66507 PC Board Assy function Replaceable Parts Contd 03555-66508 Board Assy amplifier A3 Contd 03555-66506 PC Board Assy filter A4 Contd Chassis Mounted Components Chassis Mounted Components Contd Miscellaneous Miscellaneous Contd Fscm Replacement National Part Stock Number FscmPart Number National Stock Number Cross Reference Index National Stock NumberPage Model 3555B Appendix a Code List of Manufacturers Schematic Diagrams Circuit DiagramsFunctional Block Diagram Reference Designations Section Model 3555B Functional Block Diagram 7-4 A1 Function Assembly Schematic and Component Location 7-6 7-8 A4 Filter Schematic and Component Location 7-10 11/7-12 Appendix a References Appendix B Maintenance Allocation Section I. Introduction GeneralMaintenance Function Column Entries Tool and Test Equipment Requiremen ts Sec Remarks Sec Audio Level Meter TA-885/U TM 11-7725-2779-14&P REF Code Number Appendix C Manual Backdating ChangesTransmission and Noise Measuring SET Delete CR6 across M1 Government Printing Office 1980-603-128/66 Major General, United States Army Adjutant General General, United States ArmyChief of Staff Active ArmyPage PIN