TM 11-6625-2779-14&P TECHNICAL MANUAL OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL (INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS) FOR METER, AUDIO LEVEL TA-885/U (HEWLETT-PACKARD MODEL 3555B) (NSN 6625-00-255-1083) HEADQUARTERS, DEPARTMENT OF THE ARMY 11 MARCH 1980
TM 11-6625-2779-14&P This manual contains copyrighted material reproduced by permission of Hewlett-Packard Company. reserved. TECHNICAL MANUAL All rights are HEADQUARTERS DEPARTMENT OF THE ARMY. WASHINGTON, DC, 11 March 1980 No.
SECTION III. IV. V. VI. VII. APPENDIX APPENDIX SECTION APPENDIX A. B. I. Il. III. IV. C. OPERATING INSTRUCTIONS (Cont.). Para Crosstalk measurements................................................................................................... 3-53 Identifying noise characteristics......................................................................................... 3-57 Measurements in DBC ......................................................................................................
Model 3555B Table of Contents LIST OF ILLUSTRATIONS Number Page Number Page 1-1. Model 3555B Transmission and Noise Measuring Set.................................. 1-1 4-7. Simplified Peak Detection................................ 4-7 2-1. Power Plugs ................................................. 2-1 5-1. Balanced BNC to 310 Plug .............................. 5-2 3-1. Front Panel Controls, Indicators, 5-2. Level Accuracy Check ..................................... 5-2 and Connectors .................
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 Transmission and Noise Measuring Set or simply as the 3555B. Appendix A of the manual contains a list of references and appendix B contains the maintenance allocation chart (MAC).
b. Report of Packaging and Handling Deficiencies. Fill out and forward DD Form 6 (Packaging Improvement Report) as prescribed in AR 700-58/NAVSUPINST 4030.29/AFR 71-13/MCO P4030.29A, and DLAR 4145.8. c. Discrepancy in Shipment Report (DISREP) (SF 361). Fill out and forward Discrepancy in Shipment Report (DISREP) (SF 361) as prescribed in AR 55-38/NAVSUPINST 4610.33B/AFR 75-18 MCO P4610.19C and DLAR 4500.15. 0-4.
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.
Section I Model 3555B Table 1-1. Specifications VOICE FREQUENCY LEVEL MEASUREMENTS (20Hz to 20kHz) balanced and 75 ohms unbalanced. Return loss: TERM ONLY 600 ohms: 26dB min 3kHz to 150kHz 135 ohms: 26dB min to 600kHz 75 ohms: 30dB min to 3MHz Bridging loss: less than 0.05dB at 10kHz Balance: greater than 70dB to 10kHz greater than 60dB to 100kHz greater than 40dB to 600kHz Range: -91dBm to +31dBm Level accuracy: 20Hz to 20kHz: +0.5dB 40Hz to 15kHz: +-0.
Model 3555B Section I SECTION I GENERAL INFORMATION 1-1. provided, balanced or unbalanced, bridged or terminated. For noise measurements a noise-to-ground (Ng) function is provided which provides 40dB of attenuation for longitudinal noise. For carrier frequencies 600 ohm, 135 ohm and 75 ohm impedances are provided. The 600 and 135 function can be either balanced or unbalanced, bridged or terminated; The 75 function is unbalanced only.
Section I Model 3555B Table 1-2. Accessory Equipment Supplied 1-5. A noise-to-ground (Ng) function is included which permits the measurement of longitudinal noise. When making noise-to ground measurements the impedance between INPUT terminals is greater than 80 kilohms and is 100 kilohms between each terminal and ground. A HOLD function permits holding the line while noise measurements are being made.
Model 3555B Section II SECTION II INSTALLATION 2-1. Table 2-1. Suitable Batteries Meeting NEDA 202 Specifications Manufacturer Mfr. Part No. Hewlett-Packard 1420-0026 Western Electric KS-14370 Military BA-59 Eveready 482 Burgess M-30 RCA VS013 Bright Star 3033-158, 30-33 Mallory M-202 Ray-O-Vac 202, P7830 Sears 6461 Wards 42 Wizard 3B6241 Zenith 2783 General W30B Marathon 4202 National Carbon 482 INSPECTION. 2-2. The set was carefully inspected both mechanically and electrically before shipment.
Section II 2-12. INSTALLATION BATTERY. Model 355B AND REMOVAL 2-13. To install or replace a battery, turn the four turn fasteners on the battery cover on the rear of case counterclockwise to remove the cover. Lift off cover, lift the battery out of its recess and unplug three-prong connector. POSITION TO PRESERVE BATTERY LIFE. IF THIS IS NOT BINDING, THE COVER FITS EASILY INTO PLACE. OF 1/4 the the the 2-17. REPACKAGING FOR SHIPMENT. 2-18.
Section III Model 3555B SECTION III OPERATING INSTRUCTIONS 3-1. arranged for -48V or -24V ±2V with the negative terminal of the battery connected to the tip and the ground terminal connected to the sleeve. Current consumption by the 3555B is approximately 15mA. INTRODUCTION. 3-2. The Model 3555B Transmission and Noise Measuring Set is an extremely versatile transmission and noise measuring set which satisfies many of the requirements in testing telecommunications equipment.
Section III Model 3555B Figure 3-1.
Model 3555B (1) (2) (3) (4) (5) (6) (7) (8) Section III Table 3-1. Front, Side and Rear Pane Controls, Indicators and Connectors either the S and G Jacks: Binding posts accepting banana NOISE BRDG or the NOISE TERM before the plugs, spade lugs, phone tips or bare wires for NOISE WTG filters can be selected.
Section III Model 3555B Figure 3-2.
Model 3555B Section III Table 3-1. Front, Side and Rear Panel Controls, Indicators and Connectors (Cont’d) providing connection to the input circuitry of the measuring set. When the DIAL BAT pushbutton is depressed, the INPUT jacks are connected in parallel with the DIAL/AC MON jacks. (13) Battery Cover: Removeable by four 1/4 turn screw fasteners to expose the internal battery for replacement.
Section III frequency Transmission Measuring Set (TMS) for voice, program and carrier multiplex measurements. The set will operate over a wide range of environmental conditions and maintain a high degree of accuracy. 3-16. In general, transmission level measurements are made by connecting the circuit under test to the INPUT jacks with a suitable patch cord, selecting the proper bridging or terminate condition and impedance, and then operating the RANGE switch to provide an on-scale meter indication.
Model 3555B when no input signal is present and a mechanical zero adjust is not required. The actual input level to the set is the algebraic sum of the black dBm meter scale and black RANGE setting. For example, RANGE is set to 40dBm and the meter indicates -6.3dBm. The input level is then (40) + (-6.3) = -46.3dBm. If the RANGE switch is at +20dBm and the meter indication is 4.7dBm, the level is (+20) + (4.7) = +15.3dBm. 3-24.
Section III 3-35. As an aid in identifying the source of noise, the DIAL/AC MON jacks can be used with a monitoring receiver to listen to the noise which will have approximately the same quality as that heard by a subscriber. Particular types of noise like power line induction, switching noise, atmospheric static, crosstalk or random noise may be identified by this listening test. To aid in bringing up the level of the lower frequency power line noise, the 3kHz flat weighting is used.
Model 3555B Section III Figure 3-4. Recorder Compatibility Chart Figure 3-5.
Section III Model 3555B 236A FUNCTION switch to 600 HOLD or 900 HOLD, depending on the impedance required. To receive a tone, set the 3555B FUNCTION switch to either 600 HOLD or 900 HOLD (whichever is appropriate) and change the 236A FUNCTION switch to DIAL. To send again, simply change the 236A to 600 HOLD or 900 HOLD. If holding is not required or dialing is not required, simply select the impedance and switch back and forth on the 236A FUNCTION switch. 3-48. TRANSMISSION LOSS MEASUREMENTS. 3-49.
Model 3555B Section III Figure 3-7. Test Setup for Measuring Crosstalk Coupling Loss oscillator frequency dial to an accuracy of approximately 3-58. Normally, a frequency selective voltmeter is used to identify the characteristics of transmission line ±3%. In practice, this measurement would probably be interference in order to trace it down to its origin and made using a "loop around" technique. The oscillator apply the appropriate corrective action.
Section III Model 3555B Figure 3-8. Simple Test for Inductive and Capacitive Coupling 3-70. The 3555B comes equipped with all the 0dBC = 0.775V across any impedance as read on an necessary parts for converting the 135 BAL function to a -hp- Model 400D AC Vacuum Tube Voltmeter. Thus, 150 BAL function. The following is a simplified the dBC is strictly a relative term. procedure for making the modification. 3-66. Measurements can easily be made in dBC. by a.
Model 3555B Section III Table 3-3. Level Measurement STEP 1. 2. 3. 4. 5. Table 3-4. Noise Metallic Measurements PROCEDURE STEP Turn the 3555B/ON and depress the DIAL/BAT pushbutton. The meter should indicate in the green BAT GOOD area. If it does not, replace the battery or check the power source before attempting to make any measurements. The battery test operates for internal battery, office battery or ac power source. Select either TMS BRDG or TMS TERM, depending on the measurement being made.
Section III Model 3555B Table 3-6. Balance Measurement Table 3-5. Noise-to-Ground Measurements STEP 1. 2. 3. 4. 5. STEP PROCEDURE 1. Turn the 3555B POWER switch to ON and depress the DIAL/BAT pushbutton. The meter should indicate in the green BAT GOOD area. If it does not replace the battery or check the power source. The battery test operates for internal battery, office battery or ac power source. Set the INPUT switch to NOISE BRDG.
Model 3555B Section IV SECTION IV THEORY OF OPERATION Set. Refer to this figure for the following block diagram 4-1. INTRODUCTION. description. 4-2. The Model 3555B Transmission and Noise 4-9. The input signal is first applied to the Measuring Set is a special measuring set designed for FUNCTION switch where the input circuitry is set up to uses in testing telecommunications equipment. Inputs accommodate the type of measurement being made.
Section IV Model 3555B 4-13. The output of the Input Amplifier goes to the INPUT switch where noise filters are set up for selection by the NOISE WTG switch. In the NOISE position, either 3kHz FLAT weighting, C Message weighting, 15kHz FLAT weighting or PROGRAM weighting can be selected by the NOISE WTG switch. In the TMS position of the INPUT switch the filters are bypassed for transmission level measurements. 4-14. The output from the INPUT switch goes to the meter amplifier.
Model 3555B Section IV Figure 4-3. Simplified NG Function attenuator is composed of four L pads, selectable in combinations to provide from 0dB to 80dB of attenuation. Two 30dB pads are selected by A2S1A and A2S1B, a 20dB pad is selected by A2S1C and a 10dB pad is selected by A2S1D. Another section of the RANGE attenuator switch provides gain switching for the Input Amplifier in the -80dBm, -70dBm and -60dBm positions.
Section IV RANGE Setting +30dBm +20dBm +10dBm 0dBm -10dBm -20dBm -30dBm -40dBm -50dBm -60dBm -70dBm -80dBm Model 3555B Table 4-1. Range Attenuation and Amplifier Gain RANGE ATTENUATOR Attenuation PADS USED 80dB 1,2,3 70dB 1,2,4 60dB 1,2 50dB 2,3 40dB 2,4 30dB 2 20dB 3 10dB 4 0dB 0 0dB 0 0dB 0 0dB 0 Input Amplifier Gain 3.6dB 3.6dB 3.6dB 3.6dB 3.6dB 3.6dB 3.6dB 3.6dB 3.6dB 13.6dB 23.6dB 33.6dB reducing the amplifier gain by 1.7dB.
Model 3555B Section IV Figure 4-5.
Section IV Model 3555B Figure 4-6.
Model 3555B Section IV identical in operation, only the first will be discussed in detail. 4-27. Referring to Figure 7-4, the signal is applied to the assembly through pin 22. If C MSG is selected the signal is first attenuated by A4R1, A4R2 and A4R3A. Potentiometer A4R3A is for C MSG level adjustment for 0dB at 1kHz. The signal is then applied to the first in a series of amplifiers. The first amplifier consists of A4Q1 through A4Q4.
Section IV Model 3555B voltage is filtered by C2 before being applied to the series regulator through J2, S3, CR1 and cable W1. 4-39. The regulator is of the conventional series type with A3Q19 acting as the sensing element and A3CR20 as the reference. Changes in the output level are amplified by differential amplifier A3Q18 and A3Q19. The output of the differential amplifier is amplified by A3Q20 and applied to A3Q21 which controls the conduction of the series transistor A3Q22.
Model 3555B Section V SECTION V MAINTENANCE can be substituted provided they meet the required specifications. 5-4. FACTORY SELECTED VALUES. 5-5. Factory selected values are denoted on the schematic diagrams by an asterisk. The nominal value is shown. The value in your instrument may be different or the part may be omitted. 5-6. 150 BAL CONVERSION. a. To convert the 135 BAL function to a 150 BAL 5-1. INTROOUCTION. 5-2.
Section V Model 3555B Figure 5-1. Balanced BNC to 310 Plug b. c. function, remove or clip the shorting bar from across A1 R17 (see Figure 7-2). Remove the 150 BAL decal from the small envelope supplied with the set and stick it over the existing 135 BAL decal. Adjust the 150 function as described in Paragraph 5-20 in this manual. FUNCTION........... CARRIER, 75 UNBAL INPUT .................................TMS, TERM RANGE...................................... +10dBm b. 5-7. PERFORMANCE CHECKS. 5-8.
Model 3555B Section V Table 5-2. 75 UNBAL Carrier Accuracy Check 3555B INDICATION (dBm) RANGE 30Hz to 1MHz +10dBm 0dBm -10dBm -20dBm -30dBm -40dBm -50dBm c. d. e. f. g. h. i. j. k. +10 ±0.5 0 ±0.5 -10 ±0.5 -20 ±0.5 -30 ±0.5 -40 ±0.5 -50 ±0.5 FREQUENCY 100Hz to 600kHz 1MHz to 3MHz +10 ±0.2 0 ±0.2 -10 ±0.2 -20 ±0.2 -30 ±0.2 -40 ±0.2 -50 ±0.2 +10 ±0.5 ±10% of meter indication in dBm 0 ±0.5 ±10% of meter indication in dBm -10 +0.5 ± 0% of meter indication in dBm -20 ±0.
Section V Model 3555B Figure 5-3. +20dBm and +30dBm Level Accuracy Check 5-10. FUNCTION..................VF/Nm, 600 BAL INPUT ................................TMS, TERM RANGE ........................................0dBm RETURN LOSS CHECK. a. To make a return loss check it will first be necessary to construct a balanced bridge utilizing 0.1% resistors for each of the four 3555B impedances. Figure 5-4 shows the equipment test set-up to be used.
Model 3555B Section IV Figure 5-4. Return Loss Test Set-Up d. e. f. g. Open S1 and down range the 400FL for an on-scale indication. This indication subtracted from the reference established in step c, is the bridge balance and should be greater than the return loss specification. Unplug or disconnect R4 in Figure 5-4 and connect the 3555B tip and ring in its place. Be sure to use short clip leads. Momentarily close S1 and recheck the reference on the 400FL. .
Section V Model 3555B Figure 5-6. Bridging Loss Test Set-Up j. k. l. 5-11. 1. Change the bridge resistors in Figure 5-4 to 135 ohms +0.1% and change the 3555B FUNCTION to 135 BAL. Check the return loss between 1kHz and 600kHz. The return loss must be better than 26dB down from the reference. Change the 3555B input connection to the 75 UNBAL jack. Change the resistors in Figure 5-4 to 75 ohms +0.1% and change the 3555B FUNCTION to CARRIER 75 UNBAL. Check the return loss between 1kHz and 3MHz.
Model 3555B Section V f. 1. 5-12. Reset the 654A output level for 0dBm indication on the 3555B meter at a frequency of 1kHz. 2. Check the frequencies listed in Table 5-5 for the tolerances indicated. d. PROG FILTER RESPONSE 1. Reset the 654A frequency to 1kHz and adjust the output level for 0dBm indication on the 3555B meter. 2. Check the frequencies listed in Table 5-5 for the tolerances indicated. BRIDGING LOSS. a.
Section V Model 3555B c. CARRIER 600 and repeat the above procedure. Between 1kHz and 10kHz, the balance must be greater than 70dB. Between 10kHz and 100kHz, the balance must be better than 60dB. Between 100kHz and 600kHz, balance must be better than 40dB. 5-14. ADJUSTMENT AND CALIBRATION PROCEDURE. 5-15. The following is a complete adjustment and calibration procedure for the Model 3555B.
Model 3555B Section V RESPONSE............................. DAMP c. 5-21. Adjust A3R15 for 0dBm indication on the 3555B meter. d. Change the 654A frequency to 1kHz. Change the 3555B FUNCTION switch to VF/Nm, 600 BAL. Compare the 3555B meter indication with the indication in step c. If any difference exists, adjust A3R15 to split the difference between these two indications.
Section V 5-24. Model 3555B c. Remove the two screws that secure the A3 board. d. Gently lift up the bottom of the A3 board to unplug it from the A1 FUNCTION assembly. e. Hold the bottom of the A3 board high enough to clear the FUNCTION board and pull the A3 assembly out. This is easily accomplished by gently rocking the board back and forth while pulling it down (toward the FUNCTION board). f. Once the A3 assembly has been removed, the AI FUNCTION board can be removed by pulling it out. g.
Model 3555B Section V Paragraph 5-38 Paragraph 5-37 Paragraph 5-36 Paragraph 5-35 Figure 5-8.
Section V Model 3555B Table 5-6. Front Panel Trouble Analysis INPUT CONDITIONS FUNCTION: VF/Nm 1kHz, 0dBm, 600 BAL FUNCTION DIAL BAT Input: TMS, TERM VF/Nm: 600 BAL 3555B SHOULD INDICATE (RANGE + METER)* In green area, BAT GOOD SET ACTUALLY INDICATES CORRECTIVE ACTION Replace battery 0dBm ±0.2dBm Refer to Paragraph 5-34 Change INPUT to BRDG RANGE to +10dBm +6dBm ±0.2dBm Refer to Paragraph 5-34 Depress 900 BAL +4.2dBm ±0.2dBm Refer to Paragraph 5-34 INPUT to TERM RANGE to 0dBm -0.1 5dBm ±0.
Model 3555B Section V Table 5-6. Front Panel Trouble Analysis (Cont'd) INPUT CONDITIONS FUNCTION 3555B SHOULD INDICATE (RANGE + METER)* SET ACTUALLY INDICATES CORRECTIVE ACTION LEVEL -30dBm Change RANGE to -30dBm -30dBm ±0.2dBm See Paragraph 5-35 LEVEL 40dBm Change RANGE to 400dBm -40dBm ±0.2dBm LEVEL -500dBm Change RANGE to -50dBm -50dBm ±0.2dBm LEVEL -60dBm Change RANGE to -60dBm -60dBm ±0.2dBm LEVEL -70dBm Change RANGE to -70dBm -70dBm ±0.
Section V Model 3555B properly, check the relay and the energizing ground supplied through either pins 1, 2 or 3 on XA1. 5-37. FILTER TROUBLESHOOTING. a. First determine that the set is operating in the TMS input mode. This bypasses the filters. If the set functions properly in the TMS mode, check each of the filters by applying a 1kHz signal at a 0dBm level to the set. All filters are calibrated for 0dBm indication on the 3555B meter at a frequency of 1kHz. b.
Model 3555B Section V Table 5-8. FUNCTION Switch Resistance Values NOTE The following resistance measurements were made with C1 shorted. Be sure to remove the short after completion of your measurements. FUNCTION INPUT JACKS Tip to Ring Tip to Ground BRDG TERM BRDG TERM DIAL/AC MON JACKS Ring to Ground BRDG TERM DIAL BAT NG 80.4 kilohms 80.4 kilohms NG HOLD 80.
Section V Model 3555B Table 5-9. Range Attenuation and Amplifier Gain RANGES +30 +20 +10 0 -10 -20 -30 -40 -50 -60 -70 -80 Attenuator Pads Used (See Figure 7-3) 1 2 3 4 X X X X X X X X X Ranges Affected +30 -20 If Defective +20 thru +10 +30 Table 5-11.
PERFORMANCE CHECK TEST CARD Hewlett-Packard Model 3555B Transmission and Noise Measuring Set Serial No. Tests Performed By Date DESCRIPTION CHECK CARRIER 75 UNBAL LEVEL ACCURACY CHECK 30Hz to 1MHz +10dBm Range 0dBm Range -10dBm Range -20dBm Range -30dBm Range -40dBm Range -50dBm Range +10dBm ±0.5dBm 0dBm ±0.5dBm -10dBm ±0.5dBm -20dBm ±0.5dBm -30dBm ±0.5dBm -40dBm ±0.5dBm -50dBm ±0.5dBm 100Hz to 600kHz +10dBm Range 0dBm Range -10dBm Range -20dBm Range -30dBm Range -40dBm Range -50dBm Range +10dBm ±0.
PERFORMANCE CHECK TEST CARD (Cont'd) CARRIER 600 BAL LEVEL ACCURACY CHECK 1kHz to 150kHz +10dBm Range 0dBm Range -10dBm Range -20dBm Range -30dBm Range -40dBm Range -50dBm Range +10dBm ±0.5dBm 0dBm ±0.5dBm -10dBm ±0.5dBm -20dBm ±0.5dBm -30dBm ±0.5dBm -40dBm ±0.5dBm -50dBm ±0.5dBm 10kHz to 100kHz +10dBm Range 0dBm Range -10dBm Range -20dBm Range -30dBm Range -40dBm Range -50dBm Range +10dBm ±0.2dBm 0dBm ±0.2dBm -10dBm ±0.2dBm -20dBm ±0.2dBm -30dBm ±0.2dBm -40dBm ±0.2dBm -50dBm ±0.
PERFORMANCE CHECK TEST CARD (Cont'd) RETURN LOSS CHECK 600 ohms 900 ohms VF/Nm 30Hz to 20kHz CARRIER 600 ohms, 1kHz to 150kHz 135 ohms, 1kHz to 600kHz 75 ohms, 1kHz to 3MHz FILTER RESPONSE CHECKS C-MSG 60Hz 200Hz 500Hz 1kHz 2kHz 2.5kHz 4kHz 5kHz 3kHz FLAT 60Hz 250Hz 1kHz 2kHz 2.5kHz 3kHz 15kHz FLAT 60Hz 250Hz 1kHz 5kHz 10kHz 12.
Model 3555B Section VI SECTION VI REPLACEABLE PARTS c. Typical manufacturer of the part in a five6-1. INTRODUCTION. digit code. (See Appendix A for list of 6-2. This section contains information for ordering manufacturers.) replacement parts. Table 6-1 lists parts in alphameric d. Manufacturer's part number. order of their reference designators and indicates the 6-3. Miscellaneous parts are listed at the end of description, -hp- part number of each part, together with Table 6-1.
Section VI Model 3555B Table 6-1. Replaceable Parts REFERENCE DESIGNATOR -hpPART NO. TQ DESCRIPTION MFR. MFR. PART NO. A1 03555-66507 1 PC Board Ass'y: function -hp- C1 C2.C3 C4 C5* C6 0170-0055 0180-0089 0121-4105 0160-0205 0160-2206 1 2 3 2 1 C: fxd mylar 0.
Model 3555B Section VI Table 6-1. Replaceable Parts (Cont'd) REFERENCE DESIGNATOR -hpPART NO. TQ DESCRIPTION MFR. MFR. PART NO. R6 R7 R8 R9 R10 0683-1805 0698-4342 0698-4339 0698-5095 0698-7328 1 1 1 1 1 R: fxd comp 18 ohms +/-5% 1/4W R: fxd met flm 90 kilohms +/-0.1% 1/8W R: fxd met flm 11.11 kilohms +/-0.1% 1/8W' R: fxd carbon comp 12 ohms +/-10% 1/2W R: fxd met flm 68.38 kilohms +/-0.
Section VI Model 3555B Table 6-1. Replaceable Parts (Cont'd) REFERENCE DESIGNATOR -hpPART NO. TQ DESCRIPTION MFR. MFR. PART NO. A3 (Cont'd) CR20 CR21 1902-1275 1901 0040 Diode: zener 6.2V +/-5% 400mW 7.
Model 3555B Section VI Table 6-1. Replaceable Parts (Cont'd) REFERENCE DESIGNATOR -hpPART NO. TQ DESCRIPTION MFR. MFR. PART NO. R: fxd comp 4700 ohms +/-10% 1/4W R: fxd met flm 5.49 kilohms +/-1% 1/8W R: var ww 00 ohm +/-10O% 1/2W trimmer R: fxd met flm 1.
Section VI Model 3555B Table 6-1. Replaceable Parts (Cont'd) REFERENCE DESIGNATOR -hpPART NO. TQ DESCRIPTION MFR. MFR. PART NO.
Model 3555B Section VI Table 6-1. Replaceable Parts (Cont'd) REFERENCE DESIGNATOR -hpPART NO. TQ DESCRIPTION MFR. 0698-7370 0684-1051 0684-1021 1 R: fxd met flm 17.579 kilohms +/-0.1% 1/8W R: fxd comp 1 megohm +/-10% 1/4W R: fxd comp 1000 ohms +/-10% 1/4W 91637 01121 01121 03565-60104 1 Chassis Ass’y: power supply -hp- MFR. PART NO. A4 (Cont'd) R47 R48 R49 CMF-1/10-32 CB1051 CB1021 obd CHASSIS MOUNTED COMPONENTS BT1 1420-0026 1 Battery: 45V 83740 No.
Section VI Model 3555B Table 6-1. Replaceable Parts (Cont'd) REFERENCE DESIGNATOR -hpPART NO. TQ DESCRIPTION MFR. MFR. PART NO. CHASSIS MOUNTED COMPONENTS (Cont'd) 03555-67902 1 Power Supply Ass'y -hp- R1 R2 R3 R4 R5 0757-0795 0698-4205 0698-7371 0698-3158 0698-4488 1 1 2 2 1 R: fxd met flm 75 ohms +/-1% 1/2W R: fxd met flm 21 kilohms +/-1% 1/8W R: fxd met flm 20.605 kilohms +/-0.1% 1/8W R: fxd met flm 23.7 kilohms +/-1% 1/8W R: fxd met flm 26.
Model 3555B Section VI Table 6-1. Replaceable Parts (Cont'd) REFERENCE DESIGNATOR -hpPART NO. TQ DESCRIPTION MFR. MFR. PART NO.
TM 11-6625-2779-14&P TABLE 6-2.
6-11
Model 3555B Appendix A 6-12
CODE LIST OF MANUFACTURERS (Continued) 6-13
Model 3555B Section VII SECTION VII CIRCUIT DIAGRAMS should be used in conjunction with the troubleshooting 7-1. INTRODUCTION. procedure described in Section V. 7-2. This section of the Manual contains circuit 7-5. SCHEMATIC DIAGRAMS. diagrams for the Model 3555B Transmission and Noise Measuring Set. The functional block diagram (Figure 77-6. The schematic diagrams (Figures 7-2 through 71) contains signal levels to assist in troubleshooting.
Section VII Model 3555B 7-2
Figure 7-1.
Figure 7-2.
2 Figure 7-3.
Figure 7-4.
Figure 7-5.
APPENDIX A REFERENCES DA Pam 310-4 DA Pam 310-7 TM 11-6625-320-12 TM 11-6625-683-15 TM 11-6625-2953-14 TM 38-750 TM 740-90-1 TM 750-244-2 Index of Technical Manuals, Technical Bulletins, Supply Manuals (Types 7, 8, and 9), Supply Bulletins and Lubrication Orders. US Army Equipment Index of Modification Work Orders. Operator’s and Organizational Maintenance Manual: Voltmeters ME-30A/U, and voltmeters, Electronic, ME-30B/U, ME-30C/U and ME30E/U.
APPENDIX B MAINTENANCE ALLOCATION Section I. INTRODUCTION j. Overhaul. That maintenance effort (service/action) necessary to restore an item to a completely serviceable/operational condition as prescribed by maintenance standards (i.e., DMWR) in appropriate technical publications. Overhaul is normally the highest degree of maintenance performed by the Army. Overhaul does not normally return an item to like new condition. k. Rebuild.
b. Maintenance Category. The codes in this column indicate the maintenance category allocated the tool or test equipment c. Nomenclature. This column lists the noun name and nomenclature of the tools and test equipment required to perform the maintenance functions. d. National/NATO Stock Number. This column lists the National/NATO stock number of the specific tool or test equipment. e. Tool Number.
TM 11-6625-2779-14&P SECTION II. MAINTENANCE ALLOCATION CHART FOR AUDIO LEVEL METER TA-885/U (1) (2) (3) GROUP NUMBER COMPONENT ASSEMBLY MAINTENANCE FUNCTION 00 AUDIO LEVEL METER TA-885/U (HP 3555B) Inspect Test Service Repair Overhaul B-3 (4) MAINTENANCE CATEGORY C O F H D 0.5 0.5 0.8 1.2 2.
TM 11-7725-2779-14&P SECTION III.
Model 3555B APPENDIX C MANUAL BACKDATING CHANGES Appendix C Model 3555B TRANSMISSION AND NOISE MEASURING SET This manual backdating sheet makes this manual applicable to earlier instruments. Instrument-component values that differ from those in the manual, yet are not listed in the backdating sheet, should be replaced using the part number given in the manual.
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. Page 6-8. Figure 7-5. Change No.
By Order of the Secretary of the Army: Official: E. C. MEYER General, United States Army Chief of Staff J. C. PENNINGTON Major General, United States Army The Adjutant General DISTRIBUTION: Active Army: HISA (Ft Monmouth) (21) USAINSCOM (2) COE (1) TSG (1) USAARENBD (1) DARCOM (1) TRADOC (2) OS Maj Comd (4) TECOM (2) USACC (4) MDW (1) Armies (2) Corps (2) Svc Colleges (1) USASIGS (5) USAADS (2) USAFAS (2) USAIS (2) USAFS (2) ARNG: None USAR: None For explanation of abbreviations used, see AR 310-50.
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