Page 2 - SUPPORT MAINTENANCE MANUAL (INCLUDING REPAIR PARTS AND; Para; SECTION
TM 11-6625-2779-14&P This manual contains copyrighted material reproduced by permission of Hewlett-Packard Company. All rights arereserved. TECHNICAL MANUAL HEADQUARTERS DEPARTMENT OF THE ARMY. No. 11-6625-2779-14&P WASHINGTON, DC, 11 March 1980 OPERATOR'S, ORGANIZATIONAL, DIRECT SUPPORT AND...
Page 3 - ii
SECTION III. OPERATING INSTRUCTIONS (Cont.). Para Page Crosstalk measurements ................................................................................................... 3-53 3-10 Identifying noise characteristics .................................................................................
Page 5 - pertaining to this equipment.
SECTION 0 INTRODUCTION 0-1. Scope This manual contains instructions for the operation, organizational maintenance and general support maintenance of Audio Level Meter TA-885/U. Throughout this manual, the equipment is referred to by its commercial designation of Hewlett-Packard Model 3555B Transmiss...
Page 7 - Items Comprising an Operable Equipment; the cover of the set.
0-7. Items Comprising an Operable Equipment Audio Level Meter TA-885/U includes the meter, with cover and a power cord. The power cord is stored inside the cover of the set. 0-3
Page 8 - Section I
Section I Model 3555B Table 1-1. Specifications VOICE FREQUENCY LEVEL MEASUREMENTS (20Hz balanced and 75 ohms unbalanced. to 20kHz) Return loss: TERM ONLY 600 ohms: 26dB min 3kHz to 150kHz Range: -91dBm to +31dBm 135 ohms: 26dB min to 600kHz75 ohms: 30dB min to 3MHz Level accuracy: 20Hz to 20kHz: +0...
Page 9 - The Hewlett-Packard Model 3555 B
Model 3555B Section I SECTION I GENERAL INFORMATION 1-1. INTRODUCTION. 1-2. The Hewlett-Packard Model 3555 B Transmission and Noise Measuring Set is a versatile setdesigned for uses in testing telecommunicationsequipment. The extreme sensitivity of this set, linkedwith its wide and flat frequency re...
Page 11 - NEDA 202 Specifications
Model 3555B Section II SECTION II INSTALLATION 2-1. INSPECTION. 2-2. The set was carefully inspected both mechanically and electrically before shipment. It shouldbe physically free of mars or scratches and in perfectelectrical condition on receipt. To confirm this, the setshould be inspected for phy...
Page 12 - Section II; INSTALLATION AND REMOVAL OF; To install or replace a battery, turn the four 1/4; CAUTION; The following is a general guide for repackaging
Section II Model 355B 2-12. INSTALLATION AND REMOVAL OF BATTERY. 2-13. To install or replace a battery, turn the four 1/4 turn fasteners on the battery cover on the rear of thecase counterclockwise to remove the cover. Lift off thecover, lift the battery out of its recess and unplug thethree-prong c...
Page 14 - Section III
Section III Model 3555B Figure 3-1. Front Panel Controls, Indicators, and Connectors 3-2
Page 20 - RECORDER COMPATIBILITY.; Figure 3-3. Impedance Matching 3555B to Recorder
Section III Model 3555B 3-35. As an aid in identifying the source of noise, the DIAL/AC MON jacks can be used with a monitoringreceiver to listen to the noise which will haveapproximately the same quality as that heard by asubscriber. Particular types of noise like power lineinduction, switching noi...
Page 22 - Figure 3-6. Typical Test Setup for Measuring Insertion Loss
Section III Model 3555B 236A FUNCTION switch to 600 HOLD or 900 HOLD,depending on the impedance required. To receive atone, set the 3555B FUNCTION switch to either 600HOLD or 900 HOLD (whichever is appropriate) andchange the 236A FUNCTION switch to DIAL. To sendagain, simply change the 236A to 600 H...
Page 23 - Figure 3-7. Test Setup for Measuring Crosstalk Coupling Loss
Model 3555B Section III Figure 3-7. Test Setup for Measuring Crosstalk Coupling Loss 3-58. Normally, a frequency selective voltmeter is used to identify the characteristics of transmission lineinterference in order to trace it down to its origin andapply the appropriate corrective action. As an expe...
Page 24 - Figure 3-8. Simple Test for Inductive and Capacitive Coupling; MEASUREMENT PROCEDURES.
Section III Model 3555B Figure 3-8. Simple Test for Inductive and Capacitive Coupling 0dBC = 0.775V across any impedance as read on an-hp- Model 400D AC Vacuum Tube Voltmeter. Thus,the dBC is strictly a relative term.3-66. Measurements can easily be made in dBC. by utilizing the Model 3555B Telephon...
Page 26 - Table 3-8. Transmission Loss Measurement
Section III Model 3555B Table 3-5. Noise-to-Ground Measurements STEP PROCEDURE 1. Turn the 3555B POWER switch to ON anddepress the DIAL/BAT pushbutton. The metershould indicate in the green BAT GOOD area.If it does not replace the battery or check thepower source. The battery test operates forintern...
Page 28 - DETAILED CIRCUIT DESCRIPTION.; The purpose of the function switch is to set up
Section IV Model 3555B 4-13. The output of the Input Amplifier goes to the INPUT switch where noise filters are set up for selectionby the NOISE WTG switch. In the NOISE position,either 3kHz FLAT weighting, C Message weighting,15kHz FLAT weighting or PROGRAM weighting can beselected by the NOISE WTG...
Page 32 - Section IV
Section IV Model 3555B Figure 4-6. C-MSG and 1SkHz FLAT Weighting Curves 4-6
Page 34 - POWER SUPPLY AND SERIES REGULATOR; The regulator is of the conventional series type
Section IV Model 3555B 4-35. Now consider the peak detection. (See Figure 7-5) When A3Q14 is turned on and A3Q17 is turned off,no current flows through the meter from the peakdetector When A3Q14 is turned off and A3Q17 is turnedon, the current path is as shown by the heavy lines inFigure 4-7 Diodes ...
Page 36 - LEVEL ACCURACY CHECKS.
Section V Model 3555B Figure 5-1. Balanced BNC to 310 Plug function, remove or clip the shorting barfrom across A1 R17 (see Figure 7-2). b. Remove the 150 BAL decal from the smallenvelope supplied with the set and stick itover the existing 135 BAL decal. c. Adjust the 150 function as described inPar...
Page 37 - Table 5-2. 75 UNBAL Carrier Accuracy Check; RANGE
Model 3555B Section V Table 5-2. 75 UNBAL Carrier Accuracy Check 3555B INDICATION (dBm) RANGE FREQUENCY 30Hz to 1MHz 100Hz to 600kHz 1MHz to 3MHz +10dBm +10 ± 0.5 +10 ± 0.2 +10 ±0.5 ±10% of meter indication in dBm 0dBm 0 ±0.5 0 ± 0.2 0 ±0.5 ±10% of meter indication in dBm -10dBm -10 ± 0.5 -10 ±0.2 -...
Page 38 - Section V; NOTE
Section V Model 3555B Figure 5-3. +20dBm and +30dBm Level Accuracy Check 5-10. RETURN LOSS CHECK. a. To make a return loss check it will first benecessary to construct a balanced bridgeutilizing 0.1% resistors for each of the four3555B impedances. Figure 5-4 shows theequipment test set-up to be used...
Page 40 - FILTER RESPONSE CHECKS.; C MSG FILTER RESPONSE; FREQUENCY
Section V Model 3555B Figure 5-6. Bridging Loss Test Set-Up j. Change the bridge resistors in Figure 5-4 to135 ohms +0.1% and change the 3555BFUNCTION to 135 BAL. Check the returnloss between 1kHz and 600kHz. Thereturn loss must be better than 26dB downfrom the reference. k. Change the 3555B input c...
Page 42 - ADJUSTMENT AND CALIBRATION; The following is a complete adjustment and
Section V Model 3555B CARRIER 600 and repeat the aboveprocedure. Between 1kHz and 10kHz, thebalance must be greater than 70dB.Between 10kHz and 100kHz, the balancemust be better than 60dB. Between 100kHzand 600kHz, balance must be better than40dB. 5-14. ADJUSTMENT AND CALIBRATION PROCEDURE. 5-15. Th...
Page 44 - TROUBLESHOOTING PROCEDURES.
Section V Model 3555B CARRIER function, change C4. To changethe balance on VF/Nm, change the value ofA1C9. c. To determine whether the value of thesecapacitors should be increased ordecreased, lightly touch the tip and ringbanana jack insulators and watch thedirection in which the meter indicationgo...
Page 47 - FRONT PANEL TROUBLESHOOTING.; Before attempting to troubleshoot the set, first
Model 3555B Section V Table 5-6. Front Panel Trouble Analysis (Cont'd) 3555B SHOULD INDICATE SET ACTUALLY CORRECTIVE INPUT CONDITIONS FUNCTION (RANGE + METER)* INDICATES ACTION LEVEL -30dBm Change RANGE to -30dBm -30dBm ± 0.2dBm See Paragraph 5-35 LEVEL 40dBm Change RANGE to 400dBm -40dBm ± 0.2dBm S...
Page 49 - Table 5-8. FUNCTION Switch Resistance Values
Model 3555B Section V Table 5-8. FUNCTION Switch Resistance Values NOTE The following resistance measurements were made with C1 shorted. Be sure toremove the short after completion of your measurements. INPUT JACKS DIAL/AC MON JACKS FUNCTION Tip to Ring Tip to Ground Ring to Ground BRDG TERM BRDG TE...
Page 54 - This section contains information for ordering; ORDERING INFORMATION.; To order a part, note the manufacturer's part
Model 3555B Section VI SECTION VI REPLACEABLE PARTS 6-1. INTRODUCTION. 6-2. This section contains information for ordering replacement parts. Table 6-1 lists parts in alphamericorder of their reference designators and indicates thedescription, -hp- part number of each part, together withany applicab...
Page 55 - Section VI
Section VI Model 3555B Table 6-1. Replaceable Parts REFERENCE -hp- TQ DESCRIPTION MFR. MFR. PART NO. DESIGNATOR PART NO. A1 03555-66507 1 PC Board Ass'y: function -hp- C1 0170-0055 1 C: fxd mylar 0.1uF +/-20% 200 vdcw 56289 192P10402-PTS C2.C3 0180-0089 2 C: fxd Al elect 10uF +50% -10% 150 vdcw 5628...
Page 61 - MISCELLANEOUS
Section VI Model 3555B Table 6-1. Replaceable Parts (Cont'd) REFERENCE -hp- TQ DESCRIPTION MFR. MFR. PART NO. DESIGNATOR PART NO. CHASSIS MOUNTED COMPONENTS (Cont'd) 03555-67902 1 Power Supply Ass'y -hp- R1 0757-0795 1 R: fxd met flm 75 ohms +/-1% 1/2W 91637 MFF-1/2-T-1 obd R2 0698-4205 1 R: fxd met...
Page 65 - Appendix A
Page 67 - This section of the Manual contains circuit; FUNCTIONAL BLOCK DIAGRAM.; Voltage levels have been included on the; REFERENCE DESIGNATIONS
Model 3555B Section VII SECTION VII CIRCUIT DIAGRAMS 7-1. INTRODUCTION. 7-2. This section of the Manual contains circuit diagrams for the Model 3555B Transmission and NoiseMeasuring Set. The functional block diagram (Figure 7-1) contains signal levels to assist in troubleshooting.The schematic diagr...
Page 68 - Section VII
Page 70 - Figure 7-2. A1 Function Assembly Schematic and Component Location
Figure 7-2. A1 Function Assembly Schematic and Component Location 7-5/7-6
Page 72 - Figure 7-4. A4 Filter Schematic and Component Location
Figure 7-4. A4 Filter Schematic and Component Location 7-9/7-10
Page 74 - Bulletins and Lubrication Orders.
APPENDIX A REFERENCES DA Pam 310-4 Index of Technical Manuals, Technical Bulletins, Supply Manuals (Types 7, 8, and 9), Supply Bulletins and Lubrication Orders. DA Pam 310-7 US Army Equipment Index of Modification Work Orders. TM 11-6625-320-12 Operator’s and Organizational Maintenance Manual: Voltm...
Page 77 - Inspect
TM 11-6625-2779-14&P SECTION II. MAINTENANCE ALLOCATION CHART FOR AUDIO LEVEL METER TA-885/U (1) (2) (3) (4) (5) (6) MAINTENANCE CATEGORY GROUP MAINTENANCE TOOLS AND NUMBER COMPONENT ASSEMBLY FUNCTION C O F H D EQUIPMENT REMARKS 00 AUDIO LEVEL METER TA-885/U Inspect 0.5 7 (HP 3555B) Test 0.5 1 t...
