DIGITAL VOLTMETER AN/GSM-64A
TM 11-6625-2616-14TECHNICAL MANUALOPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT, ANDGENERAL SUPPORT MAINTENANCE TMENTOFTHEARMYMAY 1973
W A R N I N GBe careful when working on the 115/230-volt ac line connections, 250volt internal circuitry and high voltage input to the instrument. Seriousinjury or death may result from contact with these terminals.DO NOT TAKE CHANCES!
TM 11-6625-2616-14T ECHNICAL M ANUALNO. 11-6625-2616-14HEADQUARTERSDEPARTMENT OF THE ARMYWASHINGTON , D.C., 18 May 1973Operator’s, Organizational, Direct Support, andGeneral Support Maintenance ManualDIGITAL VOLTMETER AN/GSM-64AParagraphPageCHAPTER 1. INTRODUCTIONSection I. -----------------------------1-1-1-31-1II. Description and -71-1CHAPTER 2. INSTALLATIONSection I. Service upon receipt of equipment ---------------------------------------------- 2-1-2-32-1II. Initial adjustment of equipment --------------------------------------------- 2-4, 2-52-3CHAPTER 3. OPERATIONSection I. Operator’s controls, indicators, and input jacks ---------------------------------- 3-1-3-33-1II. Operation under usual conditions ------------------------------------------------ 3-4-3-73-3CHAPTER 4. OPERATOR AND ORGANIZATIONAL MAINTENANCE ----------------------- 4-1-4-124-15-15. FUNCTIONING ------------- 5-1-5-186. GENERAL SUPPORT TROUBLESHOOTINGSection I. General troubleshooting --- 6-1-6-36-1II. Troubleshooting Digital Voltmeter AN/GSM-64A -------------------------------- 6-4-6-156-3REPAIRSANDADJUSTMENTSCHAPTER 7.7-1Section I. Repairs --------------------------- 7-1, 7-27-6II. Adjustment ----------------- 7-3-7-58-1CHAPTER 8. GENERAL SUPPORT TESTING PROCEDURES ------------------------------- 8-1-8-79. SHIPMENT AND LIMITED STORAGE, AND DEMOLITION TO PREVENTENEMY USESection I. Shipment and limited storage ------------------------------------------------- 9-1, 9-29-1II. Demolition of materiel to prevent enemy use -------------------------------------- 9-3, 9-49-1APPENDIX A. REFERENCESA-1B. MAINTENANCE ALLOCATION ----------- B-1Index 1INDEXi
TM 11-6625-2616-14LIST OF ILLUSTRATIONSFig. -39-4iiTitlePageDigital Voltmeter AN/GSM-64A . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-0Packaging of Digital Voltmeter AN/GSM-64A. . . . . . . . . . . . . . . . . . . . .2-2Front and rear views of AN/GSM-64A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Maximum voltages which may be applied to inputs of AN/GSM-64A without causingdamage . . . . . . . . . . . . . . . . . . . . . . . . . . .- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3Connections for typical ratio applications . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4Signal conditioning assembly mounting . . . . . . . . . . . . . . . . .4-4Bezel removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5Signal conditioning circuits, simplified schematic diagram. . . . . . . . . . . . . . . 5-2Digitizing circuits, simplified schematic diagram . . . . . . . . . . . 5-3Digitizing waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4Timing circuits, simplified schematic diagram . . . . . . . . . . . . . . . . . . . . . . . . . .5-5Integrator amplifier, simplified schematic diagram . . . . . . . . . . . . . . .5-7Null amplifier, simplified schematic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-8Reference supply, simplified schematic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-9Polarity circuits, simplified schematic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-10Auto/manual range circuitry, simplified schematic diagram . . . . . . . . . . . . . . . . . . . .5-11Types N74000A and MC846P quadruple 2-input positive nand gate logic diagram . . . . . . . . . . . . . . . . . . . . 5–12Type N7410A triple 3-input positive nand gate logic diagram . . . . . . . . . . . . . . . . . . . .5-12Type N7420A dual 4-input positive nand gate logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13Type MC830P expandable dual 4-input nand gate logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13Type N7441B bed-to-decimal decoder/driver logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14Type N7473A dual j-k masterslave flip-flop logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-5-14Type N7375B quadruple bistable latch logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15Type N7490A decade counter logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15Type 74192B synchronous 4-bit up/down counters logic diagram (part 1 of 2) . . . . . . . . . . 5-16Type 74192B synchronous 4-bit up/down counters logic diagram (part 2 of 2) . . . . . . . . . . . . . . . . . . .5-17Main board assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-3Signal conditioning assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4Lamp bulb bracket and front plate removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-2Lamp bulb bracket removal and lamp bulb leads . . . . . . . . . . . . . . . . . . . . . . . . . .7-2Integrated circuit package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-3Signal conditioning board removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4Function switch assembly replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-5Power and range switch assembly replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5Rear power switch replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-6Calibration adjustment points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-7Connections for reference adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 7Connections for vdc adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-8Signal conditioning assembly mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2Connections for DC volts test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-4Connections for DC volts ratio test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-6Connections for isolation test No. 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-8Connections for isolation test No. 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10Color code marking for MIL-STD resistors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-3Color code marking for MIL-STD capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fold-inSignal conditioning assembly, schematic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fold-inMain board assembly, schematic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fold-in
TM 11-6625-2616-14Figure 1-1. Digital Voltmeteter AN/GSM-64A.1-0
TM 11-6625-2616-14CHAPTER 1INTRODUCTIONSection I.1-1. ScopeThis manual describes Digital Voltmeter AN/GSM–64A and covers its installation and operation, operator, organizational, and general support maintenance. It includes operation underusual conditions, cleaning, and inspection of theequipment, replacement of parts available to theoperator and organizational repairman, and instructions appropriate to general support fortroubleshooting, testing, calibration, and repairing the equipment.1-2. Indexes of Publicationsa. DA Pam 310–4. Refer to the latest issueof DA Pam 310-4 to determine whether thereare new editions, changes, or additional publications pertaining to the equipment.b. DA Pam 310–7. Refer to DA Pam 310–7 todetermine whether there are modification workorders (MWO’S ) pertaining to the equipment.1-3. Forms and Recordsa. Reports of Maintenance and UnsatisfactoryEquipment. Use equipment forms and recordsGENERALin accordance with instructions given in TM38-750.b. Report of Packaging and Handling Deficiencies. Fill out and forward DD Form 6 (Report of Packaging and Handling Deficiencies) asprescribed in AR 700–58 (Army) /NAVSUP PUB378 (Navy) /AFR 71-4 (Air Force)/ and MCOP4030.29 (Marine Corps).c. Discrepancy in Shipment Report (DISREP)(SF 361). Fill out and forward Discrepancy inShipment Report (DISREP) (SF 361) as prescribed in AR 55–38 (Army) /NAVSUP PUB 459(Navy)/AFM 75-34 (Air Force)/ and MCOP4610.19 (Marine Corps).d. Reporting of Equipment Publication Improvements. The reporting of errors, omissions,and recommendations for improving this publication by the individual user is encouraged. Reports should be submitted on DA Form 2028(Recommended Changes to Publications) and forwarded direct to Commander US Army Electronics Command, ATTN: AMSEL-MA-C, FortMonmouth, N.J. 07703.Section Il. DESCRIPTION AND DATA1-4. Purpose and Usea. Digital Voltmeter AN/GSM-64A (fig. 1-1)is a five-digit digital voltmeter used to measuredc voltages in three ranges from 0.0001 voltto 1000.0 volts, and dc voltage ratio (with 1 volt to 10 volts reference input) in threeranges from 000,000 to 11999.9 percent or(with 10 volts to 100 volts reference input)in three ranges from 00.0000 to 1199.99 percent.b. Although not part of the basic equipment,AN/GSM-64A will internally accept AC/DCconversion, data output, and remote control ac-cessories. The instrument will also accept rackmounting adapters for mounting in a standard19-inch mounting rack.1-5. Technical CharacteristicsDc voltage measurements:00.0000 to 11.9999 voltsRanges ------------------000.000 to 119.999 volts---------0000.00 to 1000.0 voltsAutomatic or manualRanging -------Polarity -------- AutomaticAccuracy ------- 0.01% of reading or 1 digitResolution ---- 1 digitInput impedance Greater than 10 megohms1-1
TM jectionCommon-moderejection 0.0007% of reading per degree C.Greater than 60 db at 60 HzGreater than 120 db at 60 Hz,and greater than 140 db at dcwith 1,000 ohms unbalance ineither leadDc voltage ratio measurements:Ranges:. 1 volt to 10 volts referenceinput000.000 to 119.999%0000.00 to 119.999%.00000.0 to 11999.9% 10 volts to 100 volts reference input00.0000 to 11.9999%000.000 to 119.000%0000.00 to *1199.99%Ranging . . . . . . .Polarity . . . . . . . . .Accuracy . . . . . . . .Reference inputimpedance. . . . . .Signal inputimpedance. . . . . .Temperaturecoefficient . . . . .Balancing time . . . . . .Isolation - chassisground to signallow . . . . . . . . . . . . . . .Input power . . . . . . . . .Power consumption . .Dimensions . . . . . . . . . .Weight . . . . . . . . . . .Automatic or manualAutomatic 0.005% of reading or 1digitGreater than 50K ohmsGreater than 10 megohms 0.0007% of reading per degree C.Less than 2 secondsGreater than 200 volts deSelectable - 115/230 vac ( 10),50-60 Hz, single phaseLess than 20 watts8½ in. wide 3½ in. high 15 in. deepLess than 15 lbs1-6. Items Comprising an Operable EquipmentFederalstock r, Digital AN/GSM-64A . . . . .Technical Manual TM 11-6625-1626-14Lead, test: 34–65; 03626 . . . . . . . . . . . . . .Lead test: 34-66; 03626 . . . . . . . . . . . . . .Voltmeter, Digital ME-218A/GSM-64A1-7. Description of Equipmenta. The AN/GSM-64A Digital Voltmeter is asolid-state digital measuring instrument with 5full digits and a sixth digit which provides a 20percent over-range capability, except in the1, 000-volt range. Polarity of signal input is displayed automatically and range changing maybe either automatic, or manually controlled asselected by front-panel switches.b. In operation, the unknown input voltageapplied to the instrument is buffered and usedto charge a capacitor during a specific time interval. An internal reference is then applied todischarge the capacitor. Measuring the time interval required to discharge the capacitor indicates the unknown input which is visually displayed in neon glow tubes at the front of theinstrument.1-2Unit ofmeasurementQty ineach uniteacheacheacheacheach11111Qty furneqpmtFig. No.111111-11-11-11-11-1c. The voltmeter is portable, weighing lessthan 15 pounds. A carrying handle is providedwhich also serves as a tilt-stand for the unit.By removal of the top and bottom covers of theinstrument, internal calibration and adjustmentcontrols are easily reached and clearly labeled.Power application and function and range selection are accomplished by activation of pushbutton switches on the front panel. Signal inputbinding posts, located on the front and rear ofthe instrument, will accept standard test leadsor leads equipped with banana plugs. A powerselection switch is located on the rear of theinstrument for rapid conversion to either 115volt or 230-volt power sources. The powerlinecord is permanently attached to the rear ofthe unit and terminates in a three-pin polarizedplug. The powerline fuse is externally locatedin an extractor post on the rear of the instrument.
TM 11-6625-2616-14CHAPTER 2INSTALLATIONSection I. SERVICE UPON RECEIPT OF EQUIPMENT2-1. Unpackinga. Packaging Data. When packed for shipment, the AN/GSM-64A is placed in a carton,wrapped and sealed in scrim foil, and packedin a shipping box. A typical shipping containerand its contents are shown in figure 2-1. Thetest lead and test lead set are each packed in acardboard box and placed on top of the cartoncontaining the instrument. The technical manualis placed in a waterproof wrapper and is alsopacked on top of the carton containing the instrument. The outside dimensions of the shipping box are 20 3/8 by 11 3/4 by 9 3/4 inches.The volume of the box is 1.35 cubic feet, andthe shipping weight is 18 pounds.b. Removing Contents.(1) Cut tape on top of outer carton andfold back flaps.(2) Remove technical manual and boxescontaining test lead and test lead set.(3) Remove inner carton and remove scrimfoil from around carton.(4) Cut tape on top of carton and fold backflaps.(5) Remove cushioned top and instrumentfrom carton.(6) Remove desiccant bag from carton.NOTEDo not dispose of original packing materials. Retain for use in repackingequipment for storage or shipment.2-2. Checking Unpacked Equipmenta. Inspect the equipment for damage incurred during shipment. If the equipment has beendamaged, report the damage on DD Form 6(para 1-3).b. See that the equipment is complete as listedon the packing slip. If a packing slip is not available, check the equipment against the maintenance allocation chart (app B). Report all discrepancies in accordance with TM 38-750.Shortage of a minor assembly or part that doesnot affect proper functioning of the equipmentshould not prevent use of the equipment.c. If the equipment has been used or reconditioned, see whether it has been changed by amodification work order (MWO). If the equipment has been modified, the MWO number willappear on the rear panel near the nomenclatureplate. If modified, see that any operational instruction changes resulting from the modification have been entered in the equipment manual.NOTECurrent MWO’s applicable to the equipment are listed in DA Pam 310-7.2-3. Installation of EquipmentThe digital voltmeter is portable and self-contained, and requires no installation other thantilt-stand adjustment, power connection to asuitable ac power source, and assurance that thereadout will properly “zero” ( para 2-5).a. Tilt-Stand. The carrying-handle of the instrument also serves as a tilt-stand for the unit.(1) Slightly loosen (turn counterclockwise)the two knobs attaching the handle to the frameof the instrument.(2) Raise the front of the instrument andpull the front of the handle forward and thenpress downward and underneath the unit untilthe front of the handle (now the base of thestand) is in such a position to provide the desired angle to the instrument for easy observationof the digital readout.(3) Tighten the two knobs attaching thestand to the frame.2-1
TM 11-6625-2616-14Figure 2-1.NOTEAlways loosen the knobs before repositioning the handle. Never force thehandle to a new position while theknobs are tight.b. Fuse. The instrument is shipped with a0.25 ampere slow-blow fuse inserted in the fuse2-2holder on the rear of the unit. The fuse is suitable for either 115-volt or 230-volt operation.c. Power-Selection Switch. Be surepower-selection switch on the rear ofstrument is in the proper position: 115for 115-volt operation, or 230 showing foroperation.that thethe inshowing230-volt
TM 11-6625-2616-14Section II. INITIAL ADJUSTMENT OF EQUIPMENT2-4. Extent of Initial AdjustmentsBefore using Digital Voltmeter AN/GSM-64Afor routine operation, perfom the procedureoutlined in paragaph 2-5. These proceduresshould always be performed prior to equipmentuse after extensive shipment, a long period ofstorage, or a drastic change in temperature environment.2-5. Zeroing the ReadoutCAUTIONBe sure to follow instruction set forthin paragaph 2-3c before connectingpower cord to ac outlet. Failure to do somay cause the fuse to blow and damage to the transformer.a. Plug the power cord connector into theselected ac outlet.b. Depress PWR ON pushbutton switch. Allow 30 minutes for instrument warmup.c. Plug connector of test lead set (P/N 3465) into SIG H and SIG L input jacks.NOTEA small polarity tab sticks out fromthe connector nearest the SIG L plug;i.e., the tab sticks out to the left of theoperator when the connector is properlyinstalled.d. Insert blue plug adjacent to connector intoGUARD input jack.e. Connect the three clips of the test lead settogether. They are covered with red, black, andblue protective boots.f. Be sure that the VDC and AUTO RNGpushbutton switches are in the “in” position.g. The instrument readout should display00.0000. If it does not, adjust the ZA potentiometer by inserting a small screwdriver in theopening directly underneath the VDC pushbuttonswitch and turning the adjustment screw untilthe readout transfers from 00.0000 to 00.0001;observe the angle of the screwdriver blade. Backoff the adjustment until the readout transfersfrom 00.0000 to -00.0001; observe the angleof the screwdriver blade. Now place the adjustment halfway between these two settings. TheAN/GSM-64A is now ready to make measurements accurately, conveniently, and quickly.2-3
TM 11-6625-2616-14CHAPTER 3OPERATIONSection I. OPERATOR’S CONTROLS, INDICATORS, AND INPUT JACKS3-1. GeneralThis section lists, illustrates and describes thevarious controls, indicators, and input jacks provialed for the operation of the digital voltmeter.These items are listed, with their functions inparagaph 3-3. Operating instructions are described in section II of this chapter.3-2. Damage from Improper SettingsIf a 230-volt power source is to be used, be surethat the power-selection switch on the rear of theinstrument is in the 230 position. If this precaution is not observed, the fuse will blow andthe power transformer may be damaged.3-3. Operating Controlsr Indicators, andInput Jacks(fig. 3-1)FunctionReadout tubes -----------------VAC pushbutton switch .VDC pushbutton switch . . . . . . . . .R(%) pushbutton switch . . . . . . . .ZA potentiometers . . . . . . . . . . . . . .EXT REF VDC toggle switch . . .PWR ON pushbutton switch ---AUTO RNG pushbutton switch .RNG CHNG Pushbutton switch .SIG H input jack . . . . . . . . . . . . . .SIG L input jack . . . . . . . . . . . .GUARD input jack ------------EXT REF input jack . . . . . . . . . . .Overload indicator -------------Power-selection slide-switch .Incandescent bulbs behind mask indicate polarity of dc voltage applied to SIG Hterminal with respect to SIG L terminal in vdc and ratio modes.Gas discharge display tubes which provide the readout in decimal form, There aresix plug-in tubes, each containing the numerals 0 through 9 and a decimal point.Places the instrument in the ac voltage measurement mode if an AC/DC Converteraccessory is installed (para 1-4b).Places the instrument in the dc voltage measurement mode.Places the instrument in the ratio measurement mode. The reading displayed isthe ratio of the input voltage to the reference voltage in percent.Permits adjusting the readout to 00.0000 when input leads are shorted together.Selects external reference range of instrument.Applies vac line power to the instrument.Selects automatic ranging mode of operation.Changes range of instrument if AUTO RNG switch is in the “out” position.Front and rear jacks connect to instrument signal input.Front and rear jacks connect to instrument signal common.Front and rear jacks connect to inner guard shield,Connection for external reference voltage input.Incandescent bulb behind mask flashes Q symbol when input voltage exceeds fullscale capability of range selected if in manual range, or overall instrumentcapability if in AUTO RNG mode.Permits operation from either 115 vac or 230 vac input power source.3-1
TM 11-6625-2616-143-2
TM 11-6625-2616-14Section Il.3-4.OPERATION UNDER USUAL CONDITIONSStarting ProcedureMake sure that the instructions contained inparagraphs 2-4 and 2-5 have been followed before this procedure is started.a. Preliminary. Set the front panel controlsas follows:ControlPositionPWR ON pushbutton switch . . . . . . . . . . . . . .VAC pushbutton switch . . . . . . . . . . . . . . . . . . .VDC pushbutton switch . . . . . . . . . . . . .AUTO RNG pushbutton switch . . . . . . . . . . . .RNG CHNG pushbutton switch . . . . . . . . . . . .R(%) Pushbutton switch . . . . . . . . . . . . . . . . .EXT REF VDC toggle switch . . . . . . . . .OutOutInOutOutOutAnyb. Starting.(1) Plug power cord connector into selectedac outlet.(2) Depress PWR ON pushbutton switch.Allow 30 minutes for instrument warmup.3-5. Measurement of DC Voltagea. Be sure that the VDC pushbutton switchis in the “in” position.b. Depress AUTO RNG pushbutton switch.c. Plug connector of test lead set (P/N 3465) into SIG H and SIG L input jacks.NOTEA small polarity tab sticks out fromthe connector nearest the SIG L plug;i.e., the tab sticks out to the left ofthe operator when the connector isproperly installed.d. Insert blue plug adjacent to connector intoGUARD input jack.e. Connect blue-covered andclips of test lead set together.black-coveredWARNINGIf high voltages are to be measured,use extreme caution. Serious injury ordeath may result from contact withterminals connected to high voltagesources.CAUTIONSee figure 3-2 for maximum voltageswhich may be applied to the input jacksof the instrument without causing damage.EL6625-2616-14-TM-4Figure 3-2. Maximum voltage which may be applied toinputs of AN/GSM-64A without causing damage.f. Connect black-covered clip of test lead setto dc common of voltage source and red-coveredclip to voltage source.g. The voltmeter will select the proper rangeautomatically, displaying the voltage, decimalpoint and polarity of the input to the SIG Hjack with respect to the input of the SIG L jack.h. To select a voltage range manually, depress AUTO RNG pushbutton switch, bringingit to the “out” position. Note position of decimalpoint. Depress RNG CHNG pushbutton switchas required to reach desired range.3-6. Measuring DC Voltage Ratioa. Depress the R(%) pushbutton switch.b. Insert yellow plug of test lead (P/N 3466) into EXT REF input jack of instrument.c. Place EXT REF VDC toggle switch in proper position as determined by external referencevoltage to be applied; the switch must be in the10-1 position for an input of from 1 volt to 10 volts and must be in the 100-10 positionfor an input of from 10 volts to 100 volts.d. Connect test lead set to voltmeter and toinput voltage source as described in paragraph3-5c through f.CAUTIONDo not apply more than 100 voltsbetween the EXT REF input jack andSIG L input jack (fig. 3-2).NOTEThe AN/GSM-64A makes a three-terminal measurement in the ratio mode.Therefore, a common connection between the input source and the reference source is required. See figure 3-33-3
TM 11-6625-2616-14for typical ratio application connections. The common connection must beidentified and connected to signal lowof the AN/GSM–64A.e. Connect yellow-covered clip of test lead toexternal reference voltage source.f. The readout of the instrument will displaythe ratio of the input voltage to the externalreference voltage in percent. The polarity displayed will be the polarity of the input voltage.3-7. Stopping ProcedureTo stop the digital voltmeter, depress PWR ONpushbutton switch, bringing it to the “out” position. Disconnect test leads and remove powercord from ac power source.Figure 3-3.3-4
TM 11-6625-2616-14CHAPTER 4OPERATOR AND ORGANIZATIONAL MAINTENANCE4-1. Scope of Operator and OrganizationalMaintenanceThe maintenance duties assigned to the opeatorand organizational repairman of Digital Voltmeter AN/GSM-64A are listed below with areference to the paragraphs covering the specificmaintenance functions. These procedures do notrequire special tools or test equipment.a. Operator’s daily preventive maintenancechecks and services (para 4-4).b. Operator’s weekly preventive maintenancechecks and services (para 4-5).c. Operator’s monthly preventive maintenancechecks and services (para 4-6).d. Operator’s quarterly preventive maintenance checks and services (para 4-7).e. Cleaning (para 4-8).f. Touchup painting (para 4-9).b. Preventive Maintenance Checks and Services. The preventive maintenance checks andservices charts (para 4-4 through 4-7) outlinefunctions to be performed at specific intervals.These checks and services are to maintain Armyelectronic equipment in a combat-serviceablecondition; that is, in good general (physical)condition and in good operating condition. Toassist operators in maintaining combat serviceability, the charts indicate what to check, how tocheck, and what the normal conditions are. If adefect cannot be remedied by the operator, higher category of maintenance or repair is required.Records and reports of these checks and servicesmust be made in accordance with the requirements set forth in TM 38-750.4-3. Preventive Maintenance Checks andService PeriodsPreventive maintenance checks and services arerequired daily, weekly, and quarterly.Preventive maintenance is the systematic care,servicing, and inspection of equipment to prevent the occurrence of trouble, to reduce downtime, and to assure that the equipment is serviceable.a. Paragraph 4-4 specifies checks and servicesthat must be accomplished daily and under thespecial conditions listed below.(1) When the equipment is initially installed.(2) When the equipment is reinstalled afterremoval for any reason.(3) At least once each week. if the equipment is maintained in a standby condition.a. Systemtic Care. The procedures given inparagraphs 4-3 through 4-7 cover routine systematic care and cleaning essential to properupkeep and operation of the equipment.b. Paragraphs 4-5 through 4-7 specify additional checks and services that must be performedon a weekly, monthly, and quarterly basis, respectively.g. Troubleshooting (para 4-10).h. Organizational repairs (para 4-12).4-2. Preventive Maintenance4-4. Operator’s Daily Preventive Maintenance Checks and Services ChartSequenceNo.123ItemProcedureCompleteness . . . . . . . . . . . Check to see that the equipment is complete . . . . . . . . . . . . . .Controls . . . . . . . . . . . . . Check the mechanical action of each switch for smooth nonbinding operation. Also check for proper operation of thepushbutton switch detents and interlocks.Preliminary . . . . . . . . . . Check front panel switch for preliminary setup . . . . . . . . . .ReferencesPara 1-6, fig 1-1.Para 3-4a.4-1
TM eliminary. . . . . . . . . . .Preliminary . . . . . . . . . . .Para 2-3c.Para 2–5c, d, and e.G7Preliminary . . . . . .PWR ON switch. . . . . .8AUTO RNG switch9RNG CHNG switchCheck power-selection switch position -------------------Plug test lead set into front panel input jacks and shortleads together.Plug power cord into selected ac outlet.Depress the PWR ON pushbutton switch. Observe the readout illuminate (six digits, a decimal point, and a polaritysign).Depress the AUTO RNG pushbutton switch. Observe thatthe decimal is located in the readout as follows: XX. XXXX.The digits displayed should be all zeros; however, if theinstrument has not been completely warmed up (approximately 30 minutes), or if it has not been adjusted for zero(para 2-5), the last digit may display a 1 or a 2.Depress the AUTO RNG switch to bring it to the “out”position. Depress the
a. Digital Voltmeter AN/GSM-64A (fig. 1-1) is a five-digit digital voltmeter used to measure dc voltages in three ranges from 0.0001 volt to 1000.0 volts, and dc voltage ratio (with 1 volt to 10 volts reference input) in three ranges from 000,000 to 11999.9
A Professional GSM Alarm System designer and manufacturer! GSM Transformer Alarm System &GSM House Alarm System& GSM Telemetry Units & GSM GPRS Logging System Http://www.GSMalarmsystem.com Sales@KingPigeon.com.cn 1. Brief introduction The GSM Gate Opener RTU5015 is a very simple device which can be used for authorized door access,
2.2 The Global System for Mobile Communications (GSM) 56 2.3 The GSM Network Architecture 57 2.4 The GSM Radio Interface 58 2.5 Logical Channels in GSM 58 2.5. 1 Burst Structure for GSM 61 2.5.2 Mapping of Logical Channels in GSM 62 2.5.3 Mapping of Traffic Channels and Associaled Control Channels 65 2.5.4 Mapping of the BCCl-VCCCH 65
pembacaan baru, dan menghilangkan setiap kedip ( blinking) atau pencaca-han selama perhitungan. Voltmeter Digital Tipe Penggabungan Voltmeter jenis ini mengukur tegangan masukan rata-rata sebenarnya melalui suatu periode pengukuran yang telah tertentu, berbeda dengan Voltmeter tipe tanjak yang mencupli
would usually be the source for mains failure back up). 5. The Auto dialer will automatically start to search for the SIM card GSM network. The words "GSM Start" will appear in the display and a counting sequence from 1 to 5. If the GSM network is found, the display will change to "On GSM Ready".
A novel mechanism for anonymizing GSM calls 5 GSM Carrier: This role ff the GSM mobile phone service. We assume the entities GSM carrier A, C and B, for Alice, Carol and Bob respectively. GSM Carrier A is assumed to be malicious and all other entities are assumed to be honest but curious. De nition 1.
EO 1.2 STATE the electrical parameters measured by each of the following in-place measuring devices: a. Voltmeter EO 1.3 EXPLAIN how the following electrical test equipment and measuring devices are connected to a circuit: a. Voltmeter Voltmeter A simple DC voltmeter can be constructed by placing a resistor (R s), called a multiplier,
GSM/GPRS/GNSS HAT User Manual 1 / 32 GSM/GPRS/GNSS HAT User Manual OVERVIEW This is a handy, low power Raspberry Pi HAT which features multi communication functionalities: GSM, GPRS, GNSS and Blueto
The series--now titled ASM Handbook--continues to evolve and expand to serve the changing needs of metallurgy professionals throughout the world. One example of this evolution is the release this year of the ASM Handbook on CD-ROM. This year also marks the 50th anniversary of the classic 1948 edition of Metals Handbook--the last "regular" edition to be contained in one volume. The 1948 edition .
