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model 427a voltmeter - Artisan Technology Group

1. Figure 1 2 01791 2 INFORMATION tween your instrument and the Model 427A described in this manual Some serial numbers may have a let ter separating the two sections of the number This letter indicates the country in which the instrument was manufactured 1 9 If a letter prefixes the serial number the instrument was manufactured outside the United States 1 10 AVAILABLE ACCESSORIES 1 11 The following accessories are available to in crease the test capabilities of the Model 427A 1 12 CABLES AND ADAPTERS hp 11001A 45 test lead dual banana to BNC male hp 11002A 5 test lead dual banana to alligator clips hp 11003A 5 test lead dual banana to pencil probe and alligator clip hp 10111A shielded BNC female to banana plug adapter 1 13 PROBES hp Model 11074A 10 1 Voltage Divider Probe extends the voltage range of Model 427A by a factor of 10 hp Model 11039A 1000 1 Capacitive Voltage Divider for measuring voltages up to 24 KV hp Model 11096A High Frequency Probe ex tends the frequency range ofthe 427A to 500 MHz The voltage range is 0 25 to 30V 11096A High Frequency Probe 1 1 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A Section II SECTION INSTALLATION 2 1 INTRODUCTION 2 2 This section contains information and instruc tions necessary for installation and shipping of Mo
2. L ee LIES 22010 Lc 2 m EE E HELM E 20 K IOOK STO B O47T Figure 3 2 Impedance Correction Graph 01791 1 3 3 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com 0 T T6LTO DC RANGE DC OFFSET ATTENUATOR ir ADJUST A2 METER AL 2 OHMS INPUT DC OHMS RANGE AMBEIETER wre AT TENUATOR mm nu OHMS CAL OPTION OI POWER AC RANGE SUPPLY AC METERING ATTENUATOR AC POST ATTENUATOR CIRCUIT A2 6 7 VOLTS BATTERY SUPPLY BATTERY COMMON VOLTAGES 6 7 VOLTS 427A ROA Figure 4 1 Simplified Block Diagram Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com AI Model 427A Section IV SECTION IV THEORY OF 4 1 GENERAL 4 2 The Model 427A measures ac voltage dc voltage and resistance It is battery operated but with Op tion 01 can be powered by line voltage Figure 4 1 shows a simplified block diagram of the 427A 4 3 The Battery Regulator Al regulates the bat tery output and provides 6 7 and 6 7 volt bias sup ply to the amplifiers The 427A uses two amplifiers the DC Amplifier A1 and the A
3. TSTR transistor DPST double pole single mA milliampere s 10 piv peak inverse voltage volt s throw amperes 6 part of vacw alternating current MHz megahertz 10 hertz pos position s working voltage elect electrolytic megohm s 10 6 ohms poly polystyrene var variable encap encapsulated met flm metal film pot potentiometer vdew direct current working mfr manufacturer peak to peak voltage F farad mtg mounting 3 ppm parts per million FET field effect transistor mV millivolt s 10 volts prec precision temperature Ww watt s xd fixed micro 107 6 coefficient long term w with Gala gallium arsenide uv microvolt s 10 volts stability and or tol Mi inverse voltage GHz gigahertz 1079 hertz my Mylar 29 9 ww wirewound gd guard ed nA nanoampere 5 10 R resistor ao Ge germanium amperes Rh rhodium i ege grd ground ed NC normally closed rms root mean square ry average z 7 value shown may Ne neon rot rotary be omitted H henry ies NO normally open mercury NPO negative positive zero Se selenium no standard type num Hz z hertz cycle s per zero temperature co sect section s ber assigned selected second efficient Si silicon or special type REY 6 R Dupont de Nemours 01791 2 Artisan Technology Group Quality Instrumenta
4. 3941 Kennett Pike Wilmington 19807 Tel 302 655 6161 510 666 2214 FLORIDA Box 545 Suite 106 9999 N E 2nd Avenue Miami Shores 33153 Tel 305 754 4565 TWX 810 848 7262 0 Box 20007 Herndon Station 32814 621 Commonwealth Avenue Orlando Tel 305 841 3970 TWX 810 850 0113 Box 8128 Madeira Beach 33708 410 150th Avenue St Petersburg Tel 813 391 0211 TWX 810 863 0366 GEORGIA Box 28234 450 Interstate North Atlanta 30328 Tel 404 436 6181 TWX 810 766 4890 ILLINOIS 5500 Howard Street Skokle 60076 Tel 312 677 0400 910 223 3613 BRITISH COLUMBIA Hewlett Packard Canada Ltd 1037 West Broadway Vancouver 12 Tel 604 731 5301 610 922 5059 SALES amp SERVICE OFFICES INDIANA 3839 Meadows Drive Indianapolis 46205 Tel 317 546 4891 TWX 810 341 3263 LOUISIANA Box 856 1942 Williams Boulevard Kenner 70062 Tel 504 721 6201 810 955 5524 MARYLAND 6707 Whitestone Road Baltimore 21207 Tel 301 944 5400 TWX 710 862 0850 P O Box 1648 2 Choke Cherry Road Reckvilla 20850 Tel 301 948 6370 TWX 710 828 9684 MASSACHUSETTS 32 Hartwell Ave Lexington 02173 Tel 617 861 8960 TWX 710 326 6904 MICHIGAN 24315 Northwestern Highway Southfield 48075 Tel 313 353 9100 TWX 810 232 1532 MINNESOTA 2459 University Avenue St Paul 55114 Tel 612 645 9461 TWX 910 563 3734 MI
5. 4 rtisan Artisan Technology Group is your source for quality new and certified used pre owned equipment FAST SHIPPING AND SERVICE CENTER REPAIRS WE BUY USED EQUIPMENT DELIVERY Experienced engineers and technicians on staff Sell your excess underutilized and idle used equipment TENS OF THOUSANDS OF at our full service in house repair center We also offer credit for buy backs and trade ins IN STOCK ITEMS www artisantg com WeBuyEquipment 4 EQUIPMENT DEMOS HUNDREDS OF Instra REMOTE INSPECTION LOOKING FOR MORE INFORMATION qii Remotely inspect equipment before purchasing with Visit us the web at www artisantg com 7 for more our interactive website at www instraview com 7 information on price quotations drivers technical LEASING MONTHLY specifications manuals and documentation RENTALS ITAR CERTIFIED Contact us 888 88 SOURCE sales artisantg com www artisantg com HP Archive This vintage Hewlett Packard document was preserved and distributed by www hparchive com Please visit us on the web ocanned by on line curator Tony Gerbic Artisan puten 462 www artisantg c 427 OPERATING AND SERVICE VOLTMETER 421A Artisan Technology Group Quality Instrumentation MANUAL HEWLETT PACKARD Q 427A VOLTMETER RANGE FUNCTION 3 30 00 300 10
6. OD x 0 200 ID x 0 090 thick with anti rotation boss P O J2 Assembly binding post VOLTS red w o solder turret brass P O J2 Assembly binding post OHMS blue w o solder turret brass P O J2 0340 0099 1510 0008 1510 0037 Knob skirted bar 5 8 diameter black for 1 4 diameter shaft Holder battery Manual operating and service 0370 0077 00427 06401 00427 90005 01791 2 1 5 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com CODE LIST OF MANUFACTURERS The following code numbers are from the Federal Supply Code for Manufacturers Cataloging Handbooks H4 1 Name to Code and H4 2 Code to Name and their latest supplements The date of revision and the date of the supplements used appear at the bottom of each page Alphabetical codes have been arbitrarily assigned to Suppliers not appearing in the H4 Handbooks Code No Manufacturer Address 00000 U S A Common Any supplier of U S 00136 McCoy Electronics Mount Hotly Springs Pa 00213 Sage Electronics Corp Rochester N Y 00287 Cemco Inc Danielson Conn 00334 Humidial Colton Calif 00348 Microtron Co Inc Valley Stream N Y 00373 Garlock Inc Cherry Hill N J 00656 Aerovox Corp New Bedford Mass 00779 Amp Inc Harrisburg 00781 Aircraft Radio Corp Boonton N J 00809 Croven Ltd Whitby Ontario Canada 00815 Northern Engineering Laboratories Inc Burli
7. 1 8 W CEA T O 1 5 2100 1735 1 var ww 5 ohms 10 1 1 2 W 110 1 6 A1R7 0698 4972 2 R fxd prec met flm 499K 10 1 2 W A1R8 0757 0453 1 fxd prec met flm 30 1K 1 1 8 W CEC T O A1R9 0757 0454 1 fxd prec met flm 33 2K 1 1 8 W CEA T O A1R10 0698 4199 1 fxd prec met flm 2800 ohms 1 1 4 W MF6C T O 1 11 Not assigned A1R12 0757 0439 1 R fxd prec met flm 6810 ohms 1 1 8 W CEA T O A1R13 0757 0440 2 R fxd prec met flm 7500 ohms 1 1 8 W CEA T O AIR14 0684 3321 1 fxd comp 3300 ohms 10 1 4 W CB3321 1 15 2100 0394 1 var ww 300 ohms 20 1 1 2 W 110 A1R16 0698 4205 1 fxd prec met flm 21K 1 1 8 W CEA T O 1 17 0698 4207 1 fxd prec met flm 44 2 1 1 8 W CEA T O 1 18 2100 0328 2 var ww 500 ohms 10 1 1 2 W 110 A1R19 0757 0408 1 R fxd prec met flm 250 ohms 1 1 8 W CEA T O See Paragraph 5 73 A1R20 2100 0205 2 var ww 5000 ohms 10 1 1 2 W 1 21 0698 4202 1 fxd prec met flm 8870 ohms 1 1 8 CEA T O A1R22 0684 3911 1 R fxd comp 390 ohms 10 1 4 W CB3911 A2 00427 66502 1 Assembly board AC Metering Circuit includes thru C9 Q1 thru Q3 1 thru CR4 R1 thru R17 0180 0039 3 fxd elect 100 uF 12 vdew 30D107G012DC4M1 0160 0356 1 C fxd mica 18 pF 5 300 vdew obd See Paragraph 5 75 0130 0017 1 C var cer 8 50 pF 557 019 U2PO 34R 0180 0060 1 C fxd elect 200 uF 100 10 3 vdew 30D207G003DC4 0180 0033 1 fxd elect 50 100 10 6 vdew 30D 506G006C
8. Calif American Components Inc Conshohocken Pa ITT Semiconductor Div of Int Telephone amp Telegraph Corp West Palm Beach Fla Hewlett Packard Company Loveland Colo Cornell Dublier Electric Corp Newark N J Corning 11455 Works Corning N Y Electro Cube Inc San Gabriel Calif Willians Mfg Co San Jose Calif The Sphere Co Inc Little Falls N J Webster Electronics Co New York N Y Scionics Corp Northridge Calif Adjustable Bushing Co N Hollywood Calif Micron Electronics Garden City Long Island N Y Amprobe Inst Corp Lynbrook N Y Cabletronics Costa Mesa Calif Twentieth Century Coil Spring Co Santa Clara Calif Framingham Mass Mt View Calil Spruce Pine N C Farmington Mich Lodi N J Pasadena Calif Sem Tech Fenwal Elecl Inc Amelco Inc Spruce Pine Mica Co Omni Spectra Inc Computer Diode Corp Boots Aircraft Nut Corp Ideal Prec Meter Co Inc De Jur Meter Div Brooklyn N Y Delco Radio Div of G M Corp Kokoma Ind Thermonetics inc Canoga Park Calif Tranex Company Mountain View Calif Components Inc Biddeford Ma Hamlin Metal Products Corp Akron Ohio Angstrohm Prec inc No Hollywood Calif Siliconix Inc Sunnyvale Calif FSC Handbook Supplements Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com CODE LIST OF MANUFACTURERS Continued Model 427A Code No Manufacturer Address 17870 McGra
9. TELEATAIO Madrid Telex 2 72 49 SWEDEN Hewlett Packard Sverige AB Hagakersgatan 9C 431 04 M lndal 4 Tel 031 27 68 00 Hewlett Packard Sverige AB Svetsarvdgen 7 8171 20 Solna 1 Tel 08 98 12 50 Cable MEASUREMENTS Stockholm Telex 10721 SWITZERLAND Hewlett Packard Schweiz AG Zurcherstrasse 20 8952 Schlleren Zurich Tel 051 98 18 21 24 Cable HEWPACKAG Zurich Telex 53933 Model 427A Hewlett Packard Schweiz A G Rue du Bois du Lan 7 1217 Meyrin Geneva Tel 022 41 54 00 Cable HEWPACKSA Geneva Telex 2 24 86 TURKEY Telekom Engineering Bureau P O Box 376 Galata Istanbul Tel 49 40 40 Cable TELEMATION Istanbul UNITED KINGDOM Hewlett Packard Ltd 224 Bath Road Slaugh Bucks Tel Slough 33341 Cable HEWPIE Slough Telex 84413 YUGOSLAVIA Belram S A 83 avenue des Mimosas Brussels 15 Belgium Tel 34 33 32 34 26 19 Cable BELRAMEL Brussels Telex 21790 FOR AREAS NOT LISTED CONTACT Hewlett Packard S A Rue du Bois du Lan 7 1217 Meyrin Geneva Tel 022 41 54 00 Cable HEWPACKSA Geneva Telex 2 24 86 AFRICA ASIA AUSTRALIA ANGOLA Telectra Empresa T cnica de Equipamentos El ctricos SAR Rua de Barbosa Rodrigues 42 19 6487 Luanda Cable TELECTRA Luanda AUSTRALIA Hewlett Packard Australia Pty Ltd 22 26 Weir Street Glen tris 3146 Victoria Tel 20 1371 4 lines Cable HEWPARD Melbourne Teiex 31024 Hewlett Pac
10. nal 5 11 FREQUENCY RESPONSE CHECK 5 12 The frequency range of the hp Model 652A is 10 Hz to 10 MHz The set level indication men tioned in the following steps is used to re establish the proper amplitude each time the frequency is changed a Set S1 in Figure 5 1 to position B Set the Model 427A RANGE to 0 01 b Setthe test oscillator to 400 Hz and adjust the output for a 0 95 indication on the 427A 0 1 scale c Set test oscillator to expand and adjustthe set level control REF SET for convenient meter indication d Record set level indication for use as a re ference in steps e and f e Change the oscillator frequency to 10 Hz and reset the oscillator amplitude to the set level indication established stepe DO NOT re adjust the set level control on the oscillator The 427A indication should not vary by more than 2 minor scale divisions 296 f Repeat step e for 100 Hz 1 kHz 10 kHz 100 kHz 500 kHz and 1 MHz In each case the 427A indication should not vary by more than 2 minor scale divisions x2 6 5 13 Repeat Paragraph 5 11 with the 427A RANGE set to 3 volts and test oscillator output set to give 3 V reading on 427A in step b The 427A reading should not vary by more than 2 1 1 2 small scale divisions 9 1 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Section V 5 14 RESISTANCE ACCURACY CHECK 5 15 To check the re
11. 100 102 Fundamental 20 second harmonic Fundamental 50 112 100 110 second harmonic Fundamental 10 100 5 96 104 third harmonic Fundamental 20 102 94 108 third harmonic Fundamental 50 90 116 third harmonic 3 15 ment a Rotate FUNCTION switch to ACV NOTE With the input shorted there may be a zero offset of about two minor divisions This is caused by the bias current through the meter bridge and does not affect the accuracy of ac measurements as the meter moves upscale Use the following stepsto make an ac measure 3 2 b d Model 427A Rotate RANGE switch to approximate range of input voltage DO NOT APPLY MORE THAN 425V RMS WHEN THE INSTRUMENT IS ON RANGES ABOVE 3 OR MORE THAN 300V RMS ON RANGES BE LOW 3 Connectthe signal to be measured to the VOLTS and COM terminals and read the magnitude on the voltage scale 3 16 DB MEASUREMENTS Making dBm measurement is essen tially the same as making an ac voltage mea surement Follow the steps in Paragraph 3 13 but read the magnitude on the dB scale The 1 volt position of the RANGE switch is the 0 dBm range Each position above 1 volt is a 10 dB increase and each position below 1 volt is a 10 dBdecrease Table 3 2 lists the dB value of each range Table 3 2 DB Range Identification A given dB reading is equal to the algebraic sum of the range andthe meter reading
12. 50K 30 1 10 W fxd prec met flm 100K 1 1 8 W fxd prec met flm 44 2K 1 0 1 8 W prec met fim 68 IK 1 1 8 W fxd prec met fim 681 ohms 1 1 8 W fxd comp 27K 10 1 4 W fxd prec met flm 4750 ohms 1 1 8 W fxd comp 91 ohms 5 1 4 W See Paragraph 5 77 fxd prec met flm 7500 ohms 1 1 8 W 0002 2922 fxd prec met flm 59 0 ohms 410 1 8 W See Paragraph 5 80 R var 200 ohms 10 Type H1 Battery 22 1 2 V dry cell fxd my 0 1 20 600 vdew var trimmer 0 7 to 3 pF fxd mica 1000 pF 5 300 vdcw fxd my 0 1 uF 20 600 vdew See Option 01 See MP16 and MP18 Meter 100 nA fxd comp 10K 10 1 4 W fxd prec carbon flm 6 837 meg 1 2 W fxd prec carbon flm 2 163 meg 1 1 W fxd prec met flm 683 TK 0 5 1 4 W fxd prec met flm 216 0 5 1 4 W fxd prec met flm 68 37K 0 5 1 4 W fxd prec met flm 21 63K 0 5 1 4 W fxd prec met flm 10K 0 5 1 4 W fxd comp 1 meg 10 1 4 W fxd prec met flm 10 meg 0 25 1 2 W fxd prec met flm 31 723K 0 1 1 4 W fxd prec carbon flm 11 74 meg 1 o1W fxd prec met flm 10 15 ohms 1 1 4W fxd prec met flm 101 5 ohms 1 b 1 4W fxd prec met flm 1174 ohms 10 1 4 W fxd prec met flm 11 75K 1 1 4 W fxd prec met flm 118 8K 1 1 4 W fxd prec met flm 1 30 meg 1 1 2W ote 22240 2202 22274 30D 356G006 BB4 30D 107G012DC4M1 SZ 10939 224 obd 2N3855A obd CEA T O CEA T O 110 110 CEA T O obd UPE 70RE hp obd CEA T O obd C
13. CAPACITANCE CHECK 5 24 The 10 input resistance is shunted with 40 pF on the 0 01 through 1 volt ac ranges and with 20 pF on the 3 through 300 volt ac ranges For this input capacitance check a 100 resistor is placed ser ies with the meter input At a known frequency the reactance of the shunt capacitance will be equal to 100 kQ At this point the voltage across the input re sistance and shunt capacitance will be equal to 0 707 times the input voltage The input capacitance may be checked by finding the frequency at which the dis played voltage drops to 0 707 times the input As in put capacitance decreases the roll off frequency in creases and vice versa a Connect oscillator and Model 427A to position A of the input capacitance check Figure 5 5 and set the Model 427A FUNCTION to ACV and RANGE to 1 V b Set the oscillator frequency to 60 Hz and ad just the amplitude for a full scale display on the Model 4274 c Connect the oscillator to position B and in crease the frequency until the meter display 9 4 Artisan Technology Group Quality Instrumentation drops to 0 707 The frequency at this point should be about 40 kHz The input capacitance is nominally specified at 40 pF and may vary from instrument to instrument A frequency variation of 10 is acceptable d Repeat stepsathroughc usingthe 3 volt range of the 427A Increase the frequency in step c until the reading drops to 2 1 volts This
14. Hewlett Packard Do Brasil Henrik A Langebaek amp Kier Apartado Postal 1589 de C V Fernando Ezeta B Hewlett Packard De Venezuela 1 Ltda Ltda 27 Avenida Norte 1133 Moras 439 Avenida Petit Thouars 4719 Rua Coronel Oscar Porto 691 Carrera 7 No 48 59 San Salvador Col del Valle Miraflores Apartado 50933 20 Paulo 8 SP heres 6287 Tel 25 74 50 Mexico 12 D F Casilla 3061 Caracas ee 2 nb 1DE gt 5 75 46 49 71 88 05 71 88 69 71 99 30 able p oet an Salvador el 45 Paulo Tel 45 78 06 45 55 46 NICARAGUA P Cable HEWPACK Caracas Hewlett Packard Do Brasil l e C Ltda Avenida Franklin Roosevelt 84 grupo 203 Rie de Janeiro 2C 39 GB Tel 232 9733 Cable HEWPACK Rio de Janeiro Cable AARIS Bogota Telex 044 400 COSTA RICA Lic Alfredo Gallegos Gurdi n Apartado 3243 San Jos Tel 21 86 13 Cable GALGUR San Jos GUATEMALA Olander Associates Latin America Apartado Postal 1226 Ruta 4 6 53 Zona 4 Guatemala City Tel 63958 Cable OLALA Guatemala City Roberto Ter n G Apartado Postal 689 Edificio Ter n Managua Tel 3451 3452 Cable ROTERAN Managua PUERTO RICO San Juan Electronics Inc P O 5167 Ponce de Leon 154 Pda 3 Pta de Tierra San Juan 00906 Tel 809 725 3342 Cable SATRONICS San Juan Telex SATRON 3450 332 FOR AREAS NOT LISTED CONTACT Hewlett Packard INTERCONTIN
15. Stamping amp Tool Co Goshen Ind Code No 73899 13905 13957 14276 14455 14861 74868 74970 75042 15263 15378 75382 15818 15815 76005 76210 76433 16487 76493 76530 76545 76103 16854 11068 77075 77221 71252 11342 11630 11638 11164 11969 78189 18277 18283 18290 18424 18452 78471 78488 18493 18553 18790 18947 19136 79142 19251 19127 19963 80031 80033 80120 80131 80207 80223 80248 80294 80411 From Appendix A Monufacturer Address Electronics Corp Brooklyn N Y Jennings Radio Mfg Corp San Jose Calif Groov Pin Corp Ridgefield N J Signalite Inc Neptune N J J H Winns and Sons Winchester Mass Industrial Condenser Corp Chicago Ill R F Products Division of Amphenol Borg Electronics Corp Danbury Conn E F Johnson Co Waseca Minn International Resistance Co Philadelphia Pa Keystone Carbon Co Inc St Marys Pa CTS Knighls Inc Sandwich IH Kulka Electric Corporation Mt Vernon N Y Lenz Electric Mfg Co Chicago Ill Littlefuse Inc Des Plaines Ill Lord Mig Co Erie Pa C W Marwedel San Francisco Calif General Instrument Corp Micamold Division Newark J James Millen Mfg Co Inc Malden 855 J W Miller Co Los Angeles Calil Cinch Monadnock Div of United Carr Fastener Corp San Leandro Calif Mueller Electric Co Cleveland Ohio Nalional Union Newark N J Oak Manufacturing Co Crystal Lak
16. Sylvania Elect Prod Inc View Operations Mountain View Calif Cranford Chicago Ill Hawthorne Calif City of Industry Calif Carle Place N Y Culver Cily Calif Technical Wire Products Inc Bodine Elect Co Continental Device Corp Raytheon Mfg Co Semiconductor Div Mountain View Calif Hewlett Packard Co Boonton Radio Div Rockaway N J Los Angeles Calif Pomona Calif U S Engineering Biinn Delbert Co Burgess Battery Niagara Falls Ontario Canada Deutsch Fastener Corp Los Angeles Calif Bristol Co The Waterbury Conn Sloan Company Sun Valley Calif ITT Cannon Electric Inc Phoenix Div Phoenix Arizona National Radio Lab Inc Paramus N J CBS Electronics Semiconductor Operations Div 0 C B S Inc Lowell Mass General Electric Minial Lamp Dept Cleveland Ohio Indianapolis Ind Costa Mesa Calil Houston Texas Mel Rain Babcock Relays Div Texas Capacitor Co Code 09145 09250 08353 09569 09922 10214 10411 10646 11236 11237 11242 11312 11314 11453 11534 11711 11717 11870 12040 12136 12361 12574 12697 12128 12859 12881 12930 12954 13019 13103 13396 13835 14093 14193 14298 14433 14493 14655 14674 14752 14960 15106 15203 15287 15291 15558 15566 15631 15772 15801 15818 15037 16179 16352 16585 16688 16758 17109 17474 17554 17675 17745 17856 From Model 427A Manufa
17. a heat sink long nose pliers commercial heat sink tweezers etc onthe component lead as close to the component as possible Place the soldering iron directly on the component lead and pull up on the lead If a component is obviously damaged or faulty clip the leads close to the components and then remove the leads from the board EXCESSIVE OR PROLONGED HEAT CAN LIFT THE CIRCUIT FOIL FROM THE BOARD OR CAUSE DAMAGE TO COMPONENTS d Cleanthe component lead holes by heating the solder in the hole quickly removing the sol dering iron and inserting a pointed non metallic object such as a toothpick To mount a new component shape the leads and insert them in the holes Clip a heat sink on the component heat with the soldering iron and add solder as necessary to obtain a good electrical connection f Clipexcess leads after soldering and clean excess from the connection and adjoining area using type TF Freon hp Part No 8500 0232 5 9 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A PERFORMANCE CHECK TEST CARD Hewlett Packard Model 427A Tests performed by Voltmeter Date Serial No DESCRIPTION CHECK 1 AC ACCURACY CHECK 2 of full scale 2 FREQUENCY RESPONSE CHECK 2 10 Hz to 1 MHz 10 Hz 100 Hz 1 kHz 10 kHz 100 kHz 500 kHz 1 MHz 3 RESISTANCE ACCURACY CHECK 5 of reading at midscale Ra
18. is normal f Repeat steps a through e using the 1 volt dc range and 70 7 volt rms signal from thetrans former 0 20 INPUT IMPEDANCE CHECK 5 21 INPUT RESISTANCE CHECK 5 22 Figure 5 5 shows the setup for the input resis tance check 1 resistor is connected in series with the input and the voltage drop across the input resistance will be Rin ER Eapplied Rseries Rin With 1 volt applied will be 0 91 volt if the input resistance is 10 MQ Ep varies directly with changes in Rin a Connect the Model 427A and the voltmeter calibrator to position A illustrated in Figure 5 5 Set the Model 427A FUNCTION to DCV and RANGE to 1 V b Set the voltmeter calibrator for 1 V output c Connect the voltmeter calibrator to position B shown in Figure 5 5 hp 427A VOLTMETER VARIABLE LINE TRANSFORMER 42TA 8 053I Figure 5 4 AC Rejection Check 5 3 Guaranteed 888 88 SOURCE www artisantg com Section V TEST OSCILLATOR hp652A Model 427A hp 427A VOLTMETER IOOK 0 1 0460 al INPUT CAPACITANCE CHECK VOLTMETER CALIBRATOR hp 7 38BR o O Q o 0 427 8 1181 hp427A VOLTMETER MEG 0 1 hp 081 0473 INPUT RESISTANCE CHECK Figure 5 5 Input Impedance Check voltmeter reading should drop to 0 91 indicating an input resistance of 10 9 The input resistance may vary slightly and a tolerance of 2 should be allowed 5 23 INPUT
19. on 61 Check Power Sup Either one of R19 through R25 Ra shorted or one of R12 through R18 ly OHMS always reads o DCV and ACV ok open Intermittent operation Power supply check 1 Q4 See Paragraph 5 60 Zero offset in ACV AC Metering Circuit FUNCTION greater than 2 Meter pegs full scale on any AC range See Paragraph 5 67 AC Metering Circuit check A2CR3 and A2CR4 See Paragraph 5 67 Guaranteed 888 88 SOURCE www artisantg com Section V 0 60 POWER SUPPLY 5 61 Check at Al pin 7 for 6 4 to 7 volts and Al pin 9 for 6 4 to 7 volts If there is no output check A1Q4 first If the power supply has been overloaded A1Q4 may be bad Minimum battery voltage 15 15 9 volts 5 62 Measure the dc voltages at the check points given in Table 5 5 All measurements are made with reference to circuit ground Table 5 5 Power Supply Voltages NOTE The voltages listed in this table are nominal A tolerance of 10 should be allowed except for minimum voltages listed CHECK POINT VOLTAGE Emitter A1Q1 Collector A1Q1 Base 101 Emitter A1Q2 Collector A1Q2 Emitter A1Q3 Collector A1Q3 Collector A1Q4 Base 195 Across A1CR2 15 48V min 7 3V 14 8V 7 8V min 6 6 4 min 15V 8 6V min 0 5V 0 2 6 7 6 4 min 0 5V 6 2V 5 63 DC AMPLIFIER 5 64 To make an operational check ofth
20. on the 0 1 scale exists in ACV FUNCTION replace A2R14 with a smaller value of resistance The correct value for A2R14 is the largest value of resistance that adjusts the zero offsetto less than 2 Tracking error could result if the zero offset indica tion is reduced below 1 nominal value for A2R14 is 91 ohms hp Part 0683 9105 recommended replacement value for A2R14 is either a 47 ohm hp Part No 0683 4705 or 68 ohm hp Part 0683 6805 1 4 W 5 resistor 9 80 A2R16 0 81 A2R16 adjusts the range of the low frequency Calibration Resistor A2R17 400 CPS ADJ If the AC Metering Circuit is functioning properly and the 400 CPS ADJ cannot be adjusted for the proper indication during low frequency calibration Paragraph 5 34 A2R16 may need to be changed If the reading is consistently low change A2R16 to 56 2 ohms hp Part 0757 0395 01791 2 Section V 5 82 ETCHED CIRCUIT BOARD REPAIR 5 83 The Model 427A uses plated through double sided etched circuit boards To prevent damage to the circuit board and components observe the follow ing rules when soldering Wear clean lint free cotton or rubber gloves when handling the circuit boards Avoid touching the board or components with bare fingers as skin oils can cause leakage paths b Use a low heat 25 to 50 watts small tip soldering iron and a smalldiameter rosin core solder remove a component clip
21. should occur at about 80 kHz This verifies input capacitance of 20 pF on 3 volt range and above 5 25 ADJUSTMENT AND CALIBRATION PROCEDURES 5 26 The following adjustment and calibration pro cedures should be used only if it has been determined through the performance checks in Paragraphs 5 5 through 5 24 that the Model 427A is not performing within its specifications The location of the internal adjustments is shown in Figures 5 6 and 6 2 9 27 COVER REMOVAL 5 28 To remove the top or bottom covers remove the Phillips screws securing the cover slide the cover about 1 inch to the rear and lift it off To re place the cover reverse the removal procedure 5 29 To remove a side cover remove the four Phillips Screws and lift it off 01791 3 Guaranteed 888 88 SOURCE www artisantg com Model 427A A2C3 IOMV IMC ADJ A2RI7 A2R7 DC OF FSET 400CPS ADJ ADJ IV DC CAL VIO amp A2 Gie 00 E 0 8 0 0 00 6 O O O O O O J 2 O 00000000 4273 07 6 LEFT SIDE Figure 5 6 NOTE Before beginning the calibration be sure to adjust the mechanical meter zero according to the steps in Para graph 3 6 5 30 AMPLIFIER BALANCE AND ZERO OFFSET ADJUSTMENT short VOLTSand COM terminals set FUNC TION to either DCV or DCV b Set DC ZERO Q for zero
22. three prong connector is the ground wire 2 9 To preservethe protectionfeature when operating the instrument from atwo contact outlet use a three prong to two prong adapter and connect the pigtail on the adapter to ground 2 10 INSTALLATION 2 11 The Model 427A is fully transistorized there fore no special cooling is required However the instrument should not be operated where the ambient temperature exceeds 559C 1319 For additional information address inquiries to your local hp Sales and Service Office See Appendix B for office locations 4 12 BENCH MOUNTING 2 13 Model 427A is shipped with plastic feet and tilt stand in place ready for use as a bench instrument 01791 3 Artisan Technology Group Quality Instrumentation 2 14 RACK MOUNTING 2 15 Model 427A may be rack mounted by using an Adapter Frame hp Part No 5060 0797 The adapt er frame is a rack frame that accepts any combination of submodular units can be rack mounted only 2 16 COMBINATION MOUNTING 2 17 The Model 427A may be mounted combination with other submodular units by using a Combining Case hp Model 1051A If the 427A is equipped with carrying handle it will be necessary to remove the top cover on 427A before inserting it into Com bining Case The Combining Case is a full module unit which accepts various combinations of submodular units Being a full module unit itself it can be bench or r
23. 0 8 amp i 9 7 13 6 17 15 8 RIO 2800 125 o 12 13 15 o OM 14 13 15 945 B 5 E 9 2 R AMP BAL 12 16 15 6810 250 O ASSEMBLY 18 4 MOUNTING oP 4 S2D F 956 35 2 L i 9 E 2 12 4 S2E R M RI 2 6e7V 9 14 4 gt S2E F 9 BAT 5 R4 SEE TABLE 5 5 12 1 FOR DC VOLTGE LEVELS 150 CR5 o m m CR3 CLINE LEE E S4 97 6 7V 4 S2C R IO R5 REGADJ 22 BAT 5 R36 Model 427A FUNCTION S2B F 9 R35 BAT I58K FROM PWR SUP S2E R IO 915 216 AC METERING CIRCUIT ASSEMBLY 00427 66502 3 4 902 6e7V ASSEMBLY y MOUNTING SCREW go Sey 6 7V RI3 6 7V 6 4750 Bs 44 2 5 50 T 02 2 l 400 5 a 19 2 2 C jo 10 MV ha x R12 UN 2 27 CR3 35 IOOK 18 8 60 6 7 U RI4 1 RII 10 9I 100 68 5 RI6 7500 284 35 59 0 6 7V O 8V 4 RIO 68 1 200 6 Greub ANEN 888 88 SOURCE www artisantg com 01791 2 R36 Section V 158 FROM RANGE PWR SUP E 1 SIC R FI8 D SIC F Reo Re
24. 00 1 PACKARD HEWLETT Guaranteed 888 88 SOURCE www artisantg com VLCV dH HEWLETT PACKARD CERTIFICATION The Hewlett Packard Company certifies that this instrument was thoroughly tested and inspected and found to meet its published specifications when it was shipped from the factory The Hewlett Packard Company further certifies that its calibration measure ments are traceable to the U S National Bureau of Standards to the extent allowed by the Bureaws calibration facility WARRANTY AND ASSISTANCE All Hewlett Packard products are warranted against defects in materials and workmanship This warranty applies for one year from the date of delivery or in the case of certain major compo nents listed in the operating manual for the specified period We will repair or replace products which prove to be defective during the warranty period provided they are returned to Hewlett Packard No other warranty is expressed or implied We are not liable for consequential damages Service contracts or customer assistance agreements are available for Hewlett Packard products that require maintenance and re pair on site For any assistance contact your nearest Hewlett Packard Sales and Service Office Addresses are provided at the back of this manual Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com OPERATI
25. 1 8 W fxd prec met 1070 ohms 10 1 8 W fxd prec met fim 619 ohms 1 1 8 W fxd prec met fim 909 ohms 1 1 8 W fxd prec met flm 1020 ohms 1 1 8 W fxd prec met flm 158K 1 1 8 W var ww 200 ohms 20 DC 7 75005 8290000 Switch RANGE Switch FUNCTION Conversion Kit to Option 01 OPTION 01 fxd Al elect 150 F 100 10 40 vdew Diode Si 100 mA at 1 V 100 piv 12 pF Connector ac power cord receptacle Switch slide DPDT 115 230 Switch slide DPDT LINE BATT Transformer ac power Power cord MECHANICAL PARTS SEE FIGURE 7 1 Cover top with handle Assembly frame 6 x 8 sm Panel rear Option 01 only Panel rear Cover side 6 x 8 sm Assembly foot third module Hinge Stand tilt third module stainless steel rod Cover bottom 5 x 8 sm Panel front Meter trim third module Thumbwheel DC ZERO 9 Not assigned Holder trimmer capacitor used with C3 Shield switch DC2 CEB T O CEB T O CEB T O DC 1 CEA T O CEA T O CEA T O CEA T O CEA T O CEA T O CEA T O CEA T O CEA T O CEA T O Type 118 01791 3 Guaranteed 888 88 SOURCE www artisantg com Model 427A Section VII Table 7 1 Replaceable Parts Cont d REFERENCE hp DESIGNA TOR PART NO DESCRIPTION LE MFR PART NO 00427 05501 Shield can Option 01 only 1510 0009 Assembly binding post black COM w o solder turret brass P O J2 Insulator binding post single grey plastic 0 500
26. 30 Mount Road Madras 2 Tel 86339 Cable SICO Madras The Scientific Instrument Co Ltd 17 Society 0 Navajiwan Ahmedabad 14 Cable SICO Ahmedabad The Sclentific Instrument Co Ltd 5 8 525 Mahatma Gandhi Road Hyderabad 1 india Cable SICO Hyderabad The Scientific Instrument Co Ld B 7 Ajmeri Gate Extn New Delhi 1 Tel 27 1053 Cable SICO New Delhi INDONESIA Bah Bolon Trading Djalah Merdeka 29 Bandung Tel 4915 51550 Cable ILMU Telex 809 IRAN Telecom Ltd P 0 Box 1812 240 Kh Saba Shomali Teheran Tel 43850 48111 Cable BASCOM Teheran ISRAEL Electronics amp Englneering Div of Motorola Israel Ltd 17 Aminadav Street Tel Aviv Tel 36941 3 lines Cable BASTEL Tel Aviv Telex Baste 033 569 JAPAN Yokogawa Hewlett Packard Ltd Nisei Ibaragi Bldg 2 2 8 Kasuga Ibaragi Shi Osaka Tel 23 1641 Yokogawa Hewlett Packard Ltd Ito Building No 59 Kotori cho Nakamura ku Nagoya City Tel 551 0215 Yokogawa Hewlett Packard Ltd Ohashi Building 59 Yoyogi 1 Shibuya ku Tokyo Tel 370 2281 7 Telex 232 2024 Cable YHPMARKET TOK 23 724 KENYA R J Tilbury Ltd P Box 2754 Suite 517 518 Hotel Ambassadeur Nairobi Tel 25670 68206 58196 Cable ARJAYTEE Nairobi KOREA American Trading Co Korea Ltd P O Box 1103 Dae Kyung Bidg 107 Sejong Ro Chongro Ku Seoul T
27. 4145 Tel 216 835 0300 TWX 810 427 9129 3460 South Dixie Drive Dayton 45439 Tel 513 298 0351 TWX 810 459 1925 OKLAHOMA 2919 United Founders Boule Oklahoma City 73112 Tel 405 848 2801 TWX 910 830 6862 OREGON Westhills Mall Suite 158 4475 S W Scholls Ferry Road Portland 97225 Tel 503 292 9171 910 464 6103 PENNSYLVANIA 2500 Moss Side Boulevard Monroeville 15146 Tel 412 271 0724 TWX 710 797 3650 1021 8th Avenue King of Prussia Industrial Park King of Prussia 19406 Tel 215 265 7000 TWX 510 660 2670 RHODE ISLAND 873 Waterman Ave East Providence 02914 Tel 401 434 5535 TWX 710 381 7573 ONTARIO Hewlett Packard Canada Ltd 880 Lady Ellen Place Ottawa 3 Tel 613 722 4223 TWX 610 562 1952 Hewlett Packard Canada Ltd 50 Galaxy Blvd Rexdale Tel 416 677 9611 TWX 610 492 4246 Appendix B TEXAS P O Box 1270 201 Arapaho Rd Richardson 75080 Tel 214 231 6101 910 867 4723 6300 Westpark Drive Houston 77027 Tel 713 781 6000 TWX 910 881 2645 231 Billy Mitchell Road San Antonio 78226 Tel 512 434 4171 TWX 910 871 1170 UTAH 2890 South Main Street Salt Lake City 84115 Tel 801 487 0715 TWX 910 925 5681 VERMONT Feb 70 0 Box 2287 Kennedy Drive South Burlingtan 05401 Tel 802 658 4455 TWX 710 658 4712 VIRGINTA P O Box 6514 2111 Spencer Road Richmond 23230 Tel 703 282 5451 TWX
28. 42TA B8 0538B IO WHT BLK ORN 9 WHT BLK YEL lt 408008 8 97 6 WHT BLK GRN 9 4 WHT BRN BLU 6 8 484 RIS 4 R S 6 6 0 WHT GRN VIO m Cray WHT BRN GRN CR3 42 7 0639 ANY PLUG BOARDS ARE FOR FACTORY TEST ONLY NUMBERS STAND OFF PINS APPEAR ON SCHEMATICS 427 0540 WHT BLU YEL WHT BLK 5 TO TO OPTION OI ONLY Figure 6 2 Component Location Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com SCHEMATIC NOTES PARTIAL REFERENCE DESIGNATIONS ARE SHOWN PREFIX WITH ASSEMBLY OR SUBASSEMBLY DESIGNATION S OR BOTH FOR COMPLETE DESIGNATION COMPONENT VALUES ARE SHOWN AS FOLLOWS UNLESS OTHER WISE NOTED RESISTANCE IN OHMS CAPACITANCE IN MICROFARADS CONNECTED TO A IN OPTION 01 INSTRUMENT CONNECTED TO IN STANDARD INSTRUMENT DENOTES ASSEMBLY lt lt DENOTES OPTION 01 DENOTES MAIN SIGNAL PATH DENOTES DC FEEDBACK PATH DENOTES AC FEEDBACK PATH L DENOTES POWER LINE GROUND VOLTMETER CHASSIS V DENOTES SIGNAL GROUND CIRCUIT GROUND DENOTES FRONT PANEL MARKING LLLI DENOTES REAR PANEL MARKING DENOTES SCREWDRIVER ADJUST X AVERAGE VALUE SHOWN OPTIMUM VALUE SELECTE
29. 474 R M Bracamonte amp Co San Francisco Calif 85660 Kords Inc Hamden Conn 85911 Seamless Rubber Co Chicago lll 86174 Fafnir Bearing Co Los Angeles Calif 86197 Clifton Precision Products Co Inc Clifton Heights Pa 86579 Precision Rubber Products Corp Dayton Ohio 00015 48 Revised October 1969 Artisan Technology Group Quality Instrumentation Code 86684 86928 87034 87216 87473 87664 87930 88140 88220 88698 89231 89473 89665 90030 90179 90763 90970 91146 91260 91345 91418 91506 91637 91662 91737 91827 91886 91929 91961 92180 92367 92507 92702 92966 93332 93369 93410 93632 93929 94137 94142 94144 94148 94154 94197 94222 94330 94375 94682 94696 95023 95236 85238 95263 85265 85275 95348 95354 Manufacturer Address Radio Corp of America Electronic Comp amp Devices Div Harrison N J Seastrom Mfg Co Glendale Calif Marco Industries Anaheim Calif Philco Corporation Lansdale Division Lansdale Pa Western Fibrous Glass Products Co San Francisco Calif San Francisco Calif Providence Van Waters amp Rogers Inc Tower Mfg Corp Culler Hammer Inc Lincoln Ill Gould Nalional Batleries Inc St Paul Minn General Mills Inc Buffalo N Y Graybar Electric Co Oakland Calif Distributing Corp Schenectady N Y United Transformer Chicago IH United Shoe Machinery Corp Beverly Ma
30. 5 6 2 10 Installation 2 1 5 38 DC Calibration 5 6 2 12 Bench Mounting 2 1 5 40 Alternate Performance Checks 2 14 Rack Mounting 2 1 and Calibration Procedures 5 6 2 16 Combination Mounting 2 1 5 42 AC 5 6 2 18 Repackaging for Shipment 2 1 5 45 Resistance Circuits 5 6 5 47 DC Circus 5 7 Section Page 5 50 Rejection 5 7 II OPERATING INSTRUCTIONS 3 1 5 52 Input Impedance Check 5 7 2 1 Introduction 2525542 3 1 5 54 Battery 5 7 3 3 Front and Rear Panel 5 56 Troubleshooting 5 7 Description 3 1 5 60 Power Supply 5 8 3 5 Operating Instructions 3 1 5 63 DC Amplifier 5 8 3 6 Mechanical Zero Adjustment 3 1 5 67 Metering Circuit 9 8 3 8 Turn On 3 1 5 11 Adjustment of Factory Selected 3 11 DC Measurements 3 1 Components 5 8 3 12 Resistance Measurements 3 1 5 73 5 8 3 13 Measurements 3 2 5 75 LU po A 9 9 3 16 DB Measurements 3 2 5 77 18 4 245943 5 9 5 80 vox 2 ws 5 9 Section Page 5 82 Etched Circuit Board Repair 5 9 IV THEORY OF OPERATION 4 1 4 1 General 44 45 4408 84 4 1 Section Page 4 5 DC 4 1 VI CIRCUIT DIAGRAMS 6 1 4 7 Oh
31. 66295 66346 70276 70309 70318 70417 70485 70563 70674 70903 10998 11002 71034 11841 11218 71279 11286 71313 71400 71436 71447 71450 71468 71471 71482 71590 11616 71700 71707 71744 71185 11984 12136 12519 12656 72699 72765 72825 72928 72962 72964 12382 13061 13076 13138 73293 13445 73506 13559 73586 73682 13134 73743 73793 73846 Address Manufacturer Universal Electric Co Watd Leonard Electric Co Owosso Mich Vernon N Y Western Electric Co Inc New York N Y Weston Inst Inc Weston Newark Newark N J Witlek Mfg Chicago 111 Minnesota Mining amp Mfg Co Revere Mincom Div St Paul Minn Allen Mig Co Hartford Conn Allied Control New Yoik N Y Allmetal Screw Product Co Inc Garden City N Y Amplex Div of Chrysler Corp Detroit Mich Atlantic India Rubber Works Chicago 11 Amperite Co Inc Union City N J Products Inc Minneapolis Minn Belden Mfg Co Chicago HI Bird Electronic Corp Cleveland Ohio Birnbach Radio Co New York N Y Bliley Electric Co Inc Erie Pa Boslon Gear Works Div of Murray Co of Texas Quincy Mass Bud Radio Inc Willoughby Ohio Cambridge Thermionics Corp Cambridge Mass Camloc Fastener Corp Paramus N J Cardwell Condenser Corp Lindenhurst L I N Y Bussmann Mfg Div ol McGraw Edison Co St Louis Mo Chicago Condenser Corp Chicago 111 Calif Sp
32. 710 956 0157 WASHINGTON 433 108th Bellevue 98004 Tel 206 454 3971 TWX 910 443 2303 WEST VIRGINIA Charleston Tel 304 768 1232 FOR U S AREAS NOT LISTED Contact the regional office near est you Atlanta Georgia North Hollywood California Paramus New Jersey Skokie Illinois Their complete ad dresses are listed above Service Only QUEBEC Hewlett Packard Canada Ltd 275 Hymus Boulevard Pointe Claire Tel 514 697 4232 TWX 610 422 3022 Telex 01 20607 FOR CANADIAN AREAS NOT LISTED Contact Hewlett Packard ada Ltd in Pointe Claire at the complete address listed above CENTRAL AND SOUTH AMERICA ARGENTINA CHILE ECUADOR JAMAICA PANAMA URUGUAY Hewlett Packard Argentina H ctor Calcagni y Ltda Laboratorios de Radio Ingenleria General Engineering Services Electr nica Balboa 5 Pablo Ferrando S A 1 Bustos 1932 3er Piso Calle Guayaquil 1246 Ltd Box 4929 Comercial e Industrial Lavalle 1171 3 Casilla 13942 Post Office Box 3199 27 Dunrobin Ave Ave Manuel Espinosa No 13 50 Avenida Italia 2877 Buenos Aires Santiago Quito Kingston Bidg Alina Casila de Correo 370 Tel 35 0436 35 0627 35 0431 4 2396 Tel 12496 Tel 42657 Panama City Montevidea Cable HEWPACKARG Cable ELECTRON Panama City Cable RADIUM Montevideo COLOMBIA EL SALVADOR MEXICO BRAZIL instrumentacion Electr nica Hewlett Packard Mexicana S A PERU VENEZUELA
33. B4M1 0180 0039 C fxd elect 100 uF 12 30D 107G012DC4M1 7 2 01791 3 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A Table 7 1 Replaceable Parts Cont d Section VII REFERENCE hp T DESIGNATOR PART NO Q DESCRIPTION MFR PART NO A2C7 2 8 0180 0064 2 9 0180 0039 A2CR1 1902 0571 A2CR2 A2CR3 1910 0022 A2CR4 A2Q1 A2Q2 1854 0057 A2Q3 1853 0023 A2R1 0757 0283 0698 4202 A2R3 2100 0328 A2RA 2100 0291 A2R5 2100 0205 A2R6 0757 0449 A2R7 2100 0094 A2R8 0757 0465 A2R9 0698 4207 A2R10 0757 0461 A2R11 0757 0419 A2R12 0684 2731 A2R13 0757 0437 A2R14 0683 9105 A2R15 0757 0440 A2R16 0698 4386 A2R17 2100 3212 Bl 1420 0030 0170 0022 C3 0132 0003 C4 0140 0152 C5 0170 0022 1120 0903 0684 1031 0698 4217 0730 0113 0698 4214 0698 4212 0698 4209 0698 4206 0698 4203 0684 1051 0698 4128 0698 4129 0698 4219 0698 4189 0698 4191 0698 4198 0698 4204 0698 4210 0757 0872 01791 3 Artisan Technology Group Quality Instrumentation C fxd elect 35 uF 100 10 6 vdew C fxd elect 100 uF 12 Diode zener 14 V Not assigned Diode Ge HD1872 TSTR Si 2N3855A TSTR Si NPN 2N3703 fxd prec met flm 2000 ohms 1 1 8 W fxd prec met fIm 8870 ohms 1 1 8 W var ww 500 ohms 10 1 1 2 W var ww 1500 ohms 20 1 1 2 W var prec ww 5000 ohms 10 1 1 2 W fxd prec met flm 20K 1 7 1 8 W var pot comp lin
34. BEEBg gg B EB Bg EEG ALLL OLED EOLLLELLDLLLLLALLELL 1 EE NS ANY EE MM J D TO 946 OHMS 8 8 1 TO C3 90 7 2 2 927 93 2 2 2 2 2 2 956 967 X90 934 903 2 2 28 7 2 2 4 7 wil 4 2 2 2 2 1 2 7 7 f 1 ER NN ee CN 7 t E Z i RI TRO A 35 4 5 sth n q TO 1 TERMINAL 2 3 4 5 6 7 8 8 Tt 12 13 14 15 16 19 20 22 2 3 4 5 6 7 8 9 10 I 12 13 14 15 16 17 18 19 20 21 22 5 S SWITCH WAFERS ARE VIEWED FROM BOTTOM FRONT OF INSTRUMENT 427A 9 05618 SIA PIN NUMBERS DIFFER FROM OTHER WAFERS Figure 6 1 Location of Switch Components Artisan Technology Group Quality Instrumentation 888 88 SOURCE www artisantg com 2 IA uonoeg Vier 9POIA DC WHT BLK BLU 3 WHT BRN RED 4 9 WHT BRN YEL 5 6 1 7 8 WHT idi 9 9 ss vio 10 e 483
35. C Metering Circuit A2 The former is a high input impedance unity gainamplifier usedtoamplify dc and resistance inputs It also serves as a preamplifier for ac signals The AC Metering Circuit amplifies ac signals from the preamplifier converts them to dc signals proportional to the average ac and connects them to the meter The meter is calibrated to display the rms value of the ac input 4 4 DC Offset Adjust 2 compensates for leakage the amplifier and DC CAL and OHMS CALareresistive circuits used for calibration 4 5 DC OPERATION 4 6 Figure 4 2 shows the Model 427A in the DC Mode of Operation dc input is first applied to the DC Range Attenuator where it is attenuated by 10dB for each step of the attenuator signal from the at tenuator goes to the DC Filter and the filter rejects any ac superimposed noise that may be present on the input The output of the filter goes to the DC Am plifier 1 and then to meter DC Amplifier matches the high impedance of the attenuator to the low impedance of the meter The DC CAL circuits ATTENUATOR FILTER Figure 4 2 01791 2 OPERATION are resistive circuits in series with the meter used to adjust the meter current to calibrate the lower ranges 4 7 OHMS OPERATION 4 8 Figure 4 3 is a block diagram of the Model 427A in the OHMS Mode of Operation With the input open and forma voltag
36. D AT FACTORY DENOTES COMPONENTS NOT MOUNTED ON ASSEMBLY 24 DENOTES WIRE COLOR COLOR CODE SAME AS RESISTOR COLOR CODE FIRST NUMBER IDENTIFIES BASE COLOR SECOND NUMBER IDENTIFIES WIDER STRIP THIRD NUMBER IDENTIFIES NARROWER STRIP 924 WHITE RED YELLOW ATTENUATOR DA 9 9 R25 725M 7 2 7 5 6 R22 5 6750 5 R2I 6750 4 68 O 20 NDS 67 5 D SIFIR R 945 RIS i ONE RI2 SIE F R l9 74M 2 9 3 10155 4 5 RIS 5 RI6 12 21 75 6 14 18 8 7 RI8 16 C5 V DC RANGE S2A F ATTENUATOR VOLTS 9 o IOK SIB F R 3 Q Q Q RIS gt e RI5 9 R15 e ACV 82 9 6 837 R3 3 22165 e R4 5 683 7 8 R5 7 C2 216 3 68 37 2 9 R7 21 63 2 1 R8 12 IOK V AC RANGE ATTENUATOR Oo 0 SIA Q 8 V C3 RIO 8 7 144 ADJ 8 e 8 2 UM 2 LS RII 980 31 723 9 o 427 79 1 2 Artisan OHMS RANGE 9 0 rat N N to o FUNCTION FUNCTION P O S2C R c FILTER R6 E 499 439K 5 v o EN 6 R9 IM OPTION Ol Jl Technology Group Quality Guara
37. EA T O obd CEA T O obd CEA T O obd CB2731 CEA obd CB9105 CEA T O obd CEA T O 72 PR200 No 763 HEW 27 535 016 4 DM16F102J HEW 17 1031 DC2 DCl CEB T O CEB T O MFF 1 2 10 T 1 7 3 Guaranteed 888 88 SOURCE www artisantg com Section VII Table 7 1 Replaceable Parts Cont d Model 427A REFERENCE hp DESIGNATOR PART NO LIN DESCRIPTION R25 R26 R27 R28 R29 R30 R31 R32 R33 R34 R35 R36 R37 51 52 1 4 0698 4220 0698 4194 0698 4208 0698 4213 0730 0131 0698 4200 0698 4197 0698 4193 0698 4192 0698 4190 0698 4196 0757 0418 0757 0422 0698 4195 0698 4211 2100 1990 00427 61902 00427 61901 00427 69501 0180 1802 1901 0025 1251 2357 3101 1234 3101 0011 9100 1328 8120 1348 5060 5972 5060 0702 00427 00205 00427 00202 5000 8563 5060 0727 5040 0700 1490 0031 5000 8569 00427 00206 5020 6852 0370 0311 1450 64 00427 00601 Artisan Technology Group Quality Instrumentation fxd prec carbon flm 67 5 meg 1 2 W fxd prec met flm 675 ohms 20 57 1 4W Not assigned fxd prec met flm 67 6K 0 5 1 4 W fxd prec met fim 682K 0 5 1 4 W fxd prec carbon flm 7 5 meg 14 1 W fxd prec met flm 3419 ohms 0 25 1 8 W fxd prec met flm 1081 ohms 0 25 1 8 W fxd prec met 341 9 ohms 0 25 7 1 8W fxd prec met 108 1 ohms 0 25 1 8W fxd prec met flm 50 ohms 0 25
38. ENTAL 3200 Hillview Ave Pala Alto California 94304 Tel 415 326 7000 TWX 910 373 1267 Cable HEWPACK Palo Alto Telex 034 8461 E 1 70 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Appendix EUROPE AUSTRIA Unilabor GmbH Wissenschaftliche Instrumente Rummelhardtgasse 6 3 Box 33 Vienna 1095 Tel 42 6181 Cable LABORINSTRUMENT Vienna Telex 75 762 BELGIUM Hewlett Packard Benelux S A 348 Boulevard du Souverain Brussels 16 Tel 72 22 40 Cable PALOBEN Brussels Telex 23 494 DENMARK Hewlett Packard A S Langebjerg 6 2850 Maerum Tel 01 80 40 40 Cable HEWPACK AS Telex 66 40 FINLAND Hewlett Packard Oy Gyldenintie 3 Helsinki 20 Tel 67 35 38 Cable HEWPACKOY Helsinki Telex 12 1563 FRANCE Hewlett Packard France Quartier de Courtaboeuf Boite Postale No 6 91 Orsay Tel 920 88 01 Cable HEWPACK Orsay Telex 60048 Hewlett Packard France 4 Quai des Etroits 69 Lyon Same Tel 42 63 45 Cable HEWPACK Lyon Telex 31617 GERMANY Hewlett Packard Vertriebs GmbH Lietzenburgerstrasse 30 1 Berlin W 30 Tel 24 60 65 66 Telex 18 34 05 Hewlett Packard Vertriebs GmbH Herrenbergerstrasse 110 703 B blingen Wirttemberg Tel 07031 6671 Cable HEPAG B blingen Telex 72 65 739 Hewlett Packard Vertriebs GmbH Achenbachstrasse 15 4 D sseldorf 1 Tel 68 52 58 59 Telex 85 86 533 Hewlett Packard
39. For example if the meter reading were 6 and the instrument were on the 10 volt 20 dB range the final reading would be 20 dB 6 dB 14 dB The 427A meter is calibrated indBm 0dBm is equivalent to 0 775 volt dropped acrossa 6002 load Consequently any dBm measure ments must be made across atotal impedance of 6002 Measurements across other imped ances will be in dB not dBm To convert a dB reading to dBm use the Im pedance Correction Graph Figure 3 2 For example to convert a 30 dB reading made across a 502 load to dBm locate the 502 load impedance on the bottom of the graph Follow the impedance line to the heavy black line and read the meter correction at that point The correction for 502 is 10 5 dBm and the corrected reading is 40 5 dBm 01791 2 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A Section 25 Ae at 20 15 a E 1 E E 2 B a B E E Hl 2 i E B E 1 E Ej E a B b a il a 20011111 200210 021111 0 ee 1 ee 5 2 E METER CORRECTION DBM i B d a _ M i Bl z B a a il m
40. NG AND SERVICE MANUAL hp Part No 00427 90005 MODEL 427A VOLTMETER Serials Prefixed 947 Appendix C Manual Backdating Changes adapts manual to serials prefixed 550 621 731 Copyright Hewlett Packard Company 1969 P O Box 301 Loveland Colorado 80537 U S A Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCH bant 1972 Model 427A Table of Contents TABLE OF CONTENTS Section Page Section Page I GENERAL INFORMATION 1 1 MAINTENANCE Cont d 1 1 Description 1 1 8 7 Accuracy and Frequency 1 5 Battery 1 1 Response Check 5 1 1 7 Instrument and Manual 5 14 Resistance Accuracy Check 5 2 Identification 545554 1 1 5 16 ACCUracy 42225554 5 2 1 10 Available Accessories 1 1 5 18 AC Rejection Check 5 3 1 12 Cables and Adapters 1 1 5 20 Input Impedance Check 5 3 1 13 X 1 1 5 25 Adjustment Calibration Procedures 5 4 Section Page 5 27 Cover Removal 5 4 INSTALLATION 2 1 5 30 Amplifier Balance and Zero 2 1 Introduction s seses 2 1 Offset Adjustment 5 5 2 3 Initial Inspection 2 1 5 31 Regulator Adjust 5 5 2 5 Power Requirements 2 1 5 32 AC Calibration 5 5 2 7 Grounding Requirements 2 1 5 36 Resistance Infinity Adjustment
41. R Voltmeter Calibrator produces a 400 Hz signal that is within less than 0 2 0 of in dicated output The hp Model 652A Test Oscillator can be adjusted to within less than0 25 of a desired reference from 10 Hz to 10 MHz NOTE Before beginning the Performance Checks be sure to adjust the me chanical meter zero according to the steps in Paragraph 3 6 5 9 AC ACCURACY CHECK 5 10 Connect the test oscillator and the voltmeter calibrator as shown in Figure 5 1 a Set the voltmeter calibrator for an output of 0 01 volts at 400 Hz b Set S1 in Figure 5 1 to position A c Set the Model 427A FUNCTION to ACV and the range to 0 01 d The 427A should read 0 01 volts rms gt 2 2 minor scale division 01791 3 Repeat steps a through for each RANGE Selection through 300 V by setting the volt meter calibrator output tothefull scale value for each range The Model 427A indication should not vary from theknown inputby more than 2 on any range 2 corresponds to 2 minor divisions on the 0 1 scale and 1 1 2 minor divisions on the 0 3 scale f Set the Model 427A to the 1 volt range and apply 0 9 0 8 0 7 0 6 0 5 0 3 0 2 and 0 1 volt signals In each case the reading should be within two minor divisions of the known input signal g Set the Model 427A to the 3 volt range and apply 2 5 2 1 5 1 and 0 5 volt signals In each case the reading should be within 1 1 2 minor divisions of the knowninput sig
42. R1 has a temperature charac teristic quite similar to that of A1Q6 Therefore 01791 2 Section IV both Iggg and Ip change by approximately the same amount with temperature andthe amount of additional error at higher temperatures is lessened 4 19 AC METERING CIRCUIT A2 4 20 Figure 6 3 contains the schematic of the AC Metering Circuit The ac input from the ac post at tenuator is applied through A2C1 tothe base of 201 A2Q2 is an emitter follower that provides impedance matching to common emitter output stage A2Q3 Capacitor A2C4 provides an ac feedback path for gain stabilization 4 21 output from the collector of A2Q3 is recti fied by A2CR3 and A2CR4 and applied to the meter movement 4 22 Resistor A2R17 is used to calibrate the ampli fier at low frequency and is adjusted for full scale meter deflection witha 10 mV 400 Hz input Capacitor A2C3 is used to calibrate the amplifier at high fre quency With a 10 mV 1 MHz input A2C3 is adjusted for full scale 4 23 BATTERY REGULATOR 1 See Figure 6 3 4 24 Battery Regulator regulates the dc voltage fromthe 22 5 volt battery or from the optional power supply The voltage drop across A1CR2 and the emitter base junction of A1Q3 provides the 6 7 volt reference for the power supply and the 6 7 volt output A1Q5 senses changes the 6 7 volt output and con trols 192 the positive series regulator 191 isa current source for A1Q5 and
43. SSOURI 11131 Colorado Ave Kansas City 64137 Tel 816 763 8000 TWX 910 771 2087 MANITOBA Hewlett Packard Canada Ltd 511 Bradford Ct St James Tel 204 786 7581 TWX 610 671 3531 2812 South Brentwood Blvd St Louls 63144 Tel 314 962 5000 TWX 910 760 1670 NEW JERSEY W 120 Century Road Paramus 07652 Tel 201 265 5000 TWX 710 990 4951 1060 N Kings Highway Cherry 08034 Tel 609 667 4000 TWX 710 892 4945 NEW MEXICO Box 8366 Station C 6501 Lomas Boulevard N E Albuquerque 87108 Tel 505 255 5586 910 989 1665 156 Wyatt Drive Las Cruces 88001 Tel 505 526 2485 TWX 910 983 0550 NEW YORK 1702 Central Avenue Albany 12205 Tel 518 869 8462 710 441 8270 1219 Campville Road Endicott 13760 Tel 607 754 0050 TWX 510 252 0890 82 Washington Street Poughkeepsie 12501 Tel 914 454 7330 TWX 510 248 0012 39 Saginaw Drive Rochester 14623 Tel 716 473 9500 TWX 510 253 5981 1025 Northern Boulevard Roslyn Long Island 11576 Tel 516 869 8400 TWX 510 223 0811 NOVA SCOTIA Hewlett Packard Canada Ltd 2745 Dutch Village Rd Suite 203 Halifax Tel 902 455 0511 TWX 610 271 4482 5858 East Molloy Road Syracus 13211 Tel 315 454 2486 TWX 710 541 0482 NORTH CAROLINA P O Box 5188 1923 North Main Street High Point 27262 Tel 919 885 8101 510 926 1516 OHIO 25575 Center Ridge Road Cleveland 4
44. URCE www artisantg com Section 427 0529 OOO O 3 0 MODEL 427A FRONT PANEL A f wn 1 1 M me 7 7 gt BBM 6000 8 7757 HEWLETT PACKARD 2 v 427A VOLTMETER FUNCTION RANGE XICK 5 0 XIOOK 3 2 Q IOO 03 D 300 ONLY 0 OHMS DC ZERO OO OHMS 5 MIN 1000 00 BATT LINE option 01 only slide switch Se lects either battery or line operation 115 230 slide switch option 01 only Selects either 115 Vac or 230 Vac for line operation Line input option 01 only Connects ac operating power to instrument RANGE switch Selects appropriate range of unknown input DC ZERO Q thumbwheel Usedto electrical ly zerothe instrument in DC mode and to infinity set the instrument in OHMS mode OHMS terminal Connects unknown resistance to instrument Model 427A MODEL 427A REAR PANEL OPTION Ol 1 terminal Connects to instrument com mon Common input for ACV OHMS and DCV VOLTS terminal Applies unknown ac or dc voltage to instrument FUNCTION switch Selects mode of operation Selections are OFF BATT DC DC OHMS and AC Mechanical zero Mechanically zeroes the meter Meter face Displays the magnitude of unknown resistance or voltage in ohms or volts r
45. Vertriebs GmbH Berliner Strasse 117 6 Nieder Eschbach Frankfurt 56 Tel 0611 50 10 64 Cable HEWPACKSA Frankfurt Telex 41 32 49 Hewlett Packard Vertriebs GmbH Beim Strohhause 26 2 Hamburg 1 Tel 24 05 51 52 Cable HEWPACKSA Hamburg Telex 21 53 32 Hewlett Packard Vertriebs GmbH Reginfriedstrasse 13 8 M nchen 9 Tel 0811 69 59 71 75 Cable HEWPACKSA M nchen Telex 52 49 85 GREECE Kostas Karayannis 18 Ermou Street Athens 126 Tel 230303 232947 Cable RAKAR Athens Telex 21 59 62 RKAR GR IRELAND Hewlett Packard Ltd 224 Bath Road Slough Bucks England Tel Slough 753 3334 Cable HEWPIE Slough Telex 84413 ITALY Hewlett Packard Italiana 5 Via Amerigo Vespucci 2 20124 Milano Tel 6251 10 lines Cable HEWPACKIT Milan Telex 32046 Hewlett Packard Italiana S p A Palazzo Italia Piazza Marconi 25 00144 Rome Eur Tel 591 2544 Cable HEWPACKIT Rome Telex 61514 NETHERLANDS Hewlett Packard Benelux N V Weerdestein 117 Amsterdam Z 11 Tel 42 77 77 Cable PALOBEN Amsterdam Telex 13 216 NORWAY Hewlett Packard Norge A S Box 149 Nesveien 13 Haslum Tel 53 83 60 Cable HEWPACK Oslo Telex 6621 PORTUGAL Telectra Rua Rodrigo da Fonseca 103 0 Box 2531 Lisbon 1 Tel 68 60 72 Cable TELECTRA Lisbon Telex 1598 SPAIN Ataio Ingenieros Ganduxer 76 Barcelona 6 Tel 211 44 66 Ataio Ingenieros Enrique Larreta 12 Madrid 16 Tel 235 43 44 Cable
46. ack mounted and is analogous to any full module instrument 2 18 REPACKAGING FOR SHIPMENT 2 19 following paragraphs contain a general guide for repackaging ofthe instrumentfor shipment Refer to Paragraph 2 20 if the original container is to be used 2 21 if it is not NOTE If the instrument is to be shipped to Hewlett Packard for service or repair attach a tag to the instrument identifying the owner and indicating the service or repair to be accomplished include the model number and full serial number of the instrument In any identify the instrument by model number serial number and serial number prefix 2 20 If original container is to be used proceed as follows a Place instrument in original container original container is not available a suitable container can be purchased from your near est hp Sales and Service Office b Ensure that container is well sealed with strong tape or metal bands 2 21 If original container is notto be used proceed as follows a Wrap instrument in heavy paper or plastic before placing in an inner container b Place packing material around all sides of in strument and protect panel face with cardboard strips Place instrument and inner container inaheavy carton or wooden box and seal with strongtape or metal bands d Mark shipping container with DELICATE INSTRUMENT FRAGILE etc 2 1 Guaranteed 888 88 SO
47. ark Harrison N J 82389 Switchcrall Inc Chicago Ill 82647 Metals amp Controls Inc Spencer Products Attleboro Mass 82768 Phillips Advance Control Co Joliet 111 82866 Research Products Corp Madison 15 82877 Rolron Mfg Co Inc Woodstock N Y 82893 Vector Electronic Co Glendale Calif 82014 Hartwell Corp Los Angeles Calif 83058 Carr Fastener Co Cambridge Mass 83086 New Hampshire Ball Bearing Ine Peterborough N H 83125 General Instrument Corp Capacitor Div Darlington 5 C 83148 JTT Wire and Cable Div Los Angeles Calif 83186 Victory Eng Corp Springfield 83298 Bendix Corp Red Bank Div Red Bank N J 83315 Hubbell Corp Mundelein Ill 83324 Rosan Inc Newport Beach Calif 83320 Smith Herman H Inc Brooklyn N Y 83332 Tech Labs Palisade s Park J 83385 Central Screw Chicago Ill 83501 Gavitt Wire and Cable Co Div of Amerace Corp Brookfield Mass 83594 Burroughs Corp Electronic Tube Div Plainfield N J 83740 Union Carbide Corp Consumer Prod Div New York N Y 83777 Model Eng and Mfg Inc Huntington Ind 83821 Loyd Scruggs Co Festus Mo 83942 Aeronautical Inst amp Radio Co Lodi N J 84171 Arco Electronics Inc Great Neck N Y 84396 A J Glesener Co Inc San Francisco Calif 84411 TRW Capacitor Div Ogallala Neb 84970 Sarkes Tarzian Inc Bloomington Ind 85454 Boonton Molding Company Boonton N J 85471 Boyd San Francisco Calif 85
48. at setps a through f with the FUNCTION set to DCV and the voltmeter calibrator set for a negative output The test results should be the same THE VARIABLE LINE TRANSFORMER PROVIDES DANGEROUS AMOUNT OF POWER INSURE THAT THE CASE OF THE 427A IS GROUNDED AND THAT THE TRANSFORMER IS PROPERLY WIRED AND FUSED BEFORE PERFORMING PARAGRA PHS 5 18 5 19 5 18 AC REJECTION CHECK 2 19 peak ac superimposed noise signal 100 times the full scale input should affect the Model 427A read ing less than 1 Figure 5 4 shows the test setup using a variable line transformer as a noise generator 7 07 volt rms output from the variable line trans former corresponds to a 10 volt peak noise signal The 10 volt noise signal will be applied to the 0 1 volt dc range 01791 3 Artisan Technology Group Quality Instrumentation Section V a Set the 427A FUNCTION to DCV and short the input Set the RANGE to 0 1 and adjust the DC for 0 meter indication b Switch the FUNCTION to ACV and the RANGE to 10 Connect the variable line transform er and the Model 427A as shown in Figure 5 4 c Adjust the transformer output for a reading of 7 07 volts rms on the 427A d Switch the 427A FUNCTION to DCV andthe RANGE to 0 1 e meter reading shouldbe 0 19 1 minor scale division NOTE The meter may move upscale momentarily and then return to zero This indicatesthe charging of the DC Filter capacitors and
49. cates pin of connector XA Wire Color Color code same as resistor color code number indicates base color second number indentifies wider strip third number indicates narrower strip E g 924 denotes WHT RED YEL wire 01791 2 gr Eyelet or standoff terminal may or may not be numbered JI Destination of wire connector Assembly A3 Pin 4 Pin may or may not be numbered on a WHT RED 6 CT Female pin connector standoff pin connector STD A IIOOA 6 1 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com G T6LTO i 221 2 96 957 R37 5 29 902 2 5 4918 DENOTES WIRE COLOR 907 7 906 n3 USING STANDARD COLOR 915 2 5 CODE e g 918 WHITE aol 96 Aa LoS PRONN GAN sod os 2 3 7 A945 6 E 905 f 22212821 9 5 T so gt 2 94 o c 1 924 2 97 2 96 904 7 gll 9 Oo 903 s 5 4 928 6 2 7 2 8 9 7 7 4 7227222 2 2 4 218 1 2 7 7 7 e E 35 7 90 B 3S E EBBBBE E
50. cturer Address Tech Ind inc Alohm Elect Burbank Calif Electro Assemblies Inc Components inc Mallory Battery Co of Canada Lid Burady Corp General Transistor Western Corp Los Angeles Calif Berkeley Calif Niagara Falls N Y Berne Ind Chicago Ill Newton Mass Toronto Onlario Canada Norwalk Conn Ti Tal Inc Carborundum Co CTS of Berne Inc Chicago Telephone of California inc So Pasadena Calil Bay State Electronics Corp Waltham Mass Teledyne Inc Microwave Div Palo Alto Calif National Seal Downey Calif Precision Connector Corp Jamaica N Y Duncan Electronics Inc Gasta Mesa Calif General Instrument Corp Semiconductor Div Products Group Newark J Impenal Electronic inc Buena Park Calif Melabs Inc Palo Aito Calif National Semiconductor Danbury Conn Philadelphia Handle Co Camden Grove Mfg Co Inc Gulton Ind Inc Data System Div Albuquerque N M Dover N H W Haven Conn Tokyo Japan Clark Newporl Beach Calif Scottsdale Arizona Witchita Kansas Shady Grove Pa Claroslat Mfg Co Elmar Filter Cotp Nippon Electric Co Ltd Metex Electronics Corp Delta Semiconductor Inc Dickson Electronics Corp Airco Supply Co Inc Thermolloy Dallas Texas Telefunken GmbH Hanover Germany Midlaad Wright Div of Pacilic Industries Inc Kansas City Kansas Newbury Park Calif Calif Resistor Corp Santa Monica
51. d be replaced using the part number given in the manual Instrument Serial Prefix Make Manual Changes Instrument Serial Prefix Make Manual Changes CHANGE 1 Page 7 4 Replaceable Parts OPTION 01 Change J1 to Part No 1251 0148 Change 53 to hp Part 3101 0033 Change W1 to hp Part No 8120 0078 Change to hp Part No 00427 00203 CHANGE 2 Table 7 1 Replaceable Parts Change MP9 front panel to hp Part No 00427 00201 MP12 bracket DC ZERO Qwadjust hp Part No 00427 01201 CHANGE 3 Schematic Diagram and Replaceable Parts Remove resistor A1R22 390 Q from collector of A1Q4 NOTE Printed Circuit Board 00427 66501 with revision c or beyond has A1R22 added in collector circuit of 4104 Resistor A1R22 was added to reduce power dissipation in A1Q4 during overload CHANGE 4 Change A2R17 to 2100 2069 var ww 1000 ohms 20 1 1 2 W CHANGE 5 The cover panels and trim listed on Page 7 4 are for brown instruments Parts for blue instruments are listed below MPI Cover top 9060 5918 MP4 Cover side 5000 0702 MP8 Cover bottom 9000 8569 MPIO Meter trim 5020 6852 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com PACKARD h HEWLETT Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisahta hr D IN U S A 00427 90005 4 rtisan Artisan Technolo
52. deflection Remove shorting connectionfrom VOLTS and COM terminals If meter deflects adjust A2R OFF ADJ for zero deflection Short VOLTS and COM terminals and recheck zero adjustment Repeat steps b and c if necessary d Set the FUNCTION to DCV and turnDC ZERO fully to the right Set Range to 0 1 Re cord position of indicator e Turn FUNCTION to DCV and rotate DC ZERO amp fully to the left Note meter indication f Repeat steps d and e and adjust AIR15 BAL until the meter indication in both steps is the same NOTE If the range of adjustment A1R15 is insufficient refer to Paragraph 5 74 9 31 REGULATOR ADJUST a Complete Amplifier Balance and Offset adjust ment Paragraph 5 30 01791 2 Artisan Technology Group Quality Instrumentation A2R5 A2R4 DC CAL Section V AIRI8 AIR2O AIRIS XIK AMP BAL OHMS CAL AIRS REG ADJ OHMS CAL A O 2191917 NO 2 ie 297 Q RIGHT SIDE 3V lOOKC ADJ Location of Internal Adjustments Short VOLTS to COM and OHMS to COM Set FUNCTION to 0 Meter should be zero ed within 2 minor divisions upscale c Switch FUNCTIONtoOHMS If meter deflects adjust AIR5 REG ADJ for zero deflection This may affect DCV zero setting so rotate FUNCTION back and forth between OHMS and DCV and adjust A1R5 until meter reading is the same
53. del 427A Voltmeter Included are initial inspection pro cedures power and grounding requirements install ation and instructions for repackaging for shipment 2 3 INITIAL INSPECTION 2 4 This instrument was carefully inspected both mechanically and electrically before shipment It should be physically free of mars or scratches and in perfect electrical order upon receipt To confirm this the instrument should be inspected for physical damage in transit Also test the electrical perform ance of instrument using the procedure outlined in Paragraph 5 5 If there isdamage or deficiency see the warranty on the inside front cover of this manual 2 5 POWER REQUIREMENTS 2 6 The Model 427A uses 22 5 volt dry cell battery for its primary power source However if Option01 is included the Model 427A can be operated from any source of 115 or 230 volts 20 at 50 to 400 Hz With the instrument disconnected from the ac power source move the slide switch located on the rear panel until the desired line voltage appears Power dissipation is less than 1 2 watt maximum 2 7 GROUNDING REQUIREMENTS 2 8 To protect operating personnel the National Electrical Manufacturers Association NEMA recom mends that the instrument panel and cabinet be ground ed The Option 01 427A is equipped with a three conductor power cable which when plugged into an appropriate receptacle grounds the instrument The offset pin on the power cable
54. diodes A1CR3 CR4 and CR5 provide temperature stabilization Tran sistor A1Q4 provides a current shunt for A1CR2 to keep its voltage constant under heavy current loads 4 3 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Section V Model 427A Table 5 1 Required Test Equipment INSTRUMENT REQUIRED RECOMMENDED TYPE CHARACTERISTICS USE MODEL DC Voltage Range 0 300 V Performance Checks hp Model 738BR Volt Standard Accuracy 0 296 meter Calibrator Test Oscillator Frequency Range 10 Hz to 1 MHz Performance Checks hp Model 652A Oscil Output 0 to 3 Vac lator Variable Line Frequency Range 50 to 60 Hz Performance Checks Powerstat Type 116B Transformer Voltage Range 0 to 120 V Decade Resistor Range 102 to 10 Performance Checks General Radio Model Accuracy 0 5 1432Z Decade Resistor DC Voltmeter Range 0 50 Vdc Troubleshooting hp Model 427A Volt Accuracy 2 meter AC Voltmeter Range 0 50 Vac Troubleshooting hp Model 427A Volt Accuracy 2 meter Resistors 100 1 Performance Checks hp Part No 0811 0460 1 190 hp Part 0811 0473 Contained in hp E02 738BR Calibration System VOLTMETER CALIBRATION SYSTEM VOLTMETER VOLTMETER CALIBRATOR p738BR TEST OSCILLATOR 652 427A 8 1180 Figure 5 1 AC Accuracy and Frequency Response Check 5 0 01791 2 Artisan Technology Gr
55. e Ill The Bendix Corp Electrodynamics Div N Hollywood Calil Pacific Melals Co San Francisco Calif Phanostran Instrument and Electronic Co South Pasadena Calif Philadelphia Steel and Wire Corp Philadelphia American Machine amp Foundry Co Potter amp Srumfield Div Princeton Ind TRW Electronic Components Div Camden General Instrument Corp Rectifier Div Brooklyn N Y Resistance Products Co Harrisburg Rubbercraft Corp of Calif Torrance Calif Shakeproof Division of Illinois Tool Works Elgin Sigma So Braintree Mass Signal Indicator Carp New York N Y Struthers Dunn Inc Pitman N J Speciality Leather Prod Newark N J Thompson Bremer amp Co Chicago Ill Tilley Mfg Co San Francisco Calif Stackpole Carbon Co St Marys Pa Standard Thomson Tinnerman Products Inc Transformer Engineers Co Waldes Kohinoor inc Veeder Root Inc Wenco Mfg Co Continental Witt Electronics Corp Philadelphia Pa Zierck Mfg Corp New Rochelle N Y Mepco Division of Sessions Clock Co Morristown N J Waltham Mass Cleveland Ohio San Gabriel Calif Newtonville Mass Long Island City N Y Hartford Conn Chicago Prestole Corp Toledo Ohio Schnitzer Alloy Products Co Elizabeth J Electronic Industries Association Any brand Tube meeting EtA Standards Washington DC Unimax Swilch Div Maxon Electronics Corp Wallingford Co
56. e affects reading less than 1 Maximum 450 volts peak Overload 1200 Vdc on any range AC VOLTMETER Voltage Ranges 10 mV to 300 V rms full scale 1 3 10 sequence 10 ranges Frequency Range 10 Hz to 1 MHz Accuracy 09C to 509C RANGE 2 OF FULL SCALE 0 01 V 30 V 10 Hz 1 10 Hz 100 100 V 300 V Frequency Response SHz IMHz 2 3MHz 4MHz Frequency response 10 mV to 30 V ranges 1 0 AC VOLTMETER Cont d Input Impedance 10 megohms shunted by 40pF on 10 mV to 1 V ranges 20 pf on 3 V to 300 V ranges Response Responds to the average value of the in put calibrated in rms voltsfor a sine wave input Overload 300 V rms momentarily 1 V range and below 425 V rms maximum above 1 V range Resistance Ranges 10 ohms center scale to 10 meg ohms center scale 7 ranges Accuracy 5 of reading at midscale 0 C to 509 Polarity Common terminal negative source Current OPEN CIRCUIT SHORT CIRCUIT RANGE VOLTAGE CURRENT GENERAL Floating Input May be operated up to 500 Vde above ground Ohms input open in any function except ohms volts input open when instrument is in off position Power 22 1 2 volt dry cell battery Eveready No 763 or RCA VS102 Option 01 Battery operation and ac line opera tion selectable on rear panel 115 or 230 V 20 50 Hz to 400Hz 1 2 W 01791 2 Artisan Technology Group Quality Inst
57. e divider The voltage across R causes full scale current toflow through the meter OHMS CAL circuit adjusts meter current for indication of with the input open When R is equal tothe parallel combination of R4 and Rp the total re sistance from the OHMS terminal to ground will be half the parallel combination of R4 and Rp the voltage into the amplifier will be halved and the meter indi cation will be halfscale The Model 427A is designed sothat thefull RANGE setting will be displayed in the center of the scale For example 10 Q onthe X10 range is a center scale reading 4 9 AC OPERATION 4 10 Figure 4 4 shows a block diagram of the 427A in the AC Mode of Operation The input signal goes to the AC Range Attenuator On the 1 volt range and be low the signal is not affected by the AC Range Attenuator but on all the higher ranges the signal is attenuated 504 Capacitor C3 adjusts the frequency response of the attenuator with a 3 volt 100 KHz input The signal from the AC Range Attenuator goes through the DC Amplifier to the AC Post Attenuator where it is attenuated by 10 dB for each step of the RANGE selector The DC Amplifier matches the low impe dance of the Post Attenuator to the high impedance of the Range Attenuator acting as a preamplifier DC AMPLIFIER FEEDBACK DC Operation Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Sectio
58. e polarity of the input b Short the VOLTS input tothe COM input ro 3 7 Before any measurements are made complete tate RANGE to 0 1 and adjustthe DC ZERO the Mechanical Zero Adjustment inthe following steps 9 thumbwheel for zero meter deflection Remove shorting connection If there is zero offset with and VOLTS open refer to Paragraph 4 16 and Paragraph 5 30 b Rotate Mechanical Zero Adjustment screw d Select approximate range of input with RANGE CLOCKWISE until meter pointer istothe left switch of zero and moving upscale toward zero c Continue to rotate adjustment screw clockwise STOP when needle is exactly on zero If needle overshoots repeat step b DO NOT APPLY MORE THAN 1200 VDC TO ANY DC RANGE d When pointer is exactly over zero rotate adjustment screw slightly COUNTERCLOCK e Connect input across VOLTS and COM ter WISE to relieve tension on suspension If minals and read magnitude of input on meter the pointer moves to the left repeat whole procedure but make the counterclockwise 3 12 RESISTANCE MEASUREMENTS rotation less 3 8 TURN ON PROCEDURE DAMAGE TO 427A INPUT CIR 3 9 STANDARD INSTRUMENT CUIT MAY RESULT IF DC OR AC VOLTAGE IS APPLIED TO Rotate the FUNCTION Switch to BATT 1 5 a Rotate the FUNCTION switch to OHMS b The meter should read 1 5 or higher on the b Selectthe approximate range withthe RANGE 0 3 scale on any range indicat
59. eDC Ampli fier set the RANGE switch to 1 and the FUNCTION switchto DCV Connecta 1 volt sourcetothe VOLTS and COM terminals and monitor the voltage at A1 pin 8 Since the DC Amplifier is unity gain amplifier the voltage should be 1 07 0 07 volts dc If this reading is correct the DC Amplifier is operating properly If it is incorrect proceed with the follow ing troubleshooting procedures 5 65 Check at the collector of A1Q9 for 3 5 Vdc and check for 3 0 Vdc at AITP1 If the voltage at the collector of A1Q9 is quite high 6 or 7 volts and the voltage at is 3 0 Vdc 199 is probably open If the collector voltage is low and the test point voltage is correct A1Q8 is probably shorted If both voltages are incorrect 197 A1Q8 is probably bad 5 66 the collector voltage 109 is correct and the voltage at 1 1 is slightly higher than normal 106 is probably bad NOTE If A1Q6 is replaced and the meter remains pegged or indicates upscale and cannot be adjusted check the value of factory selected component A1R19 See Paragraph 5 71 5 73 9 8 Artisan Technology Group Quality Instrumentation Model 427A 9 67 AC METERING CIRCUIT 5 68 To check the AC Metering Circuit set the RANGE to 0 01 and the FUNCTION to ACV Connect 10 mV rms source to the VOLTS and COM terminals and monitor the signal at 2 0 The signal at 2 pin 0 should be 10 7 mV rms 0 7 mV If t
60. eeded to calibrate the dc ranges A2R3 A2R4 and A2R5 are adjusted for 9 6 42 full scale inputs onthe 0 1 0 3 and 1 volt ranges respectively The 3 volt through 1000 volt ranges are calibrated by A2R5 and require no special cali bration Use the test setup in Figure 5 3 Set FUNCTION to DCV and RANGE to 0 1 Set the voltmeter calibrator output to 0 1 volt b Adjust A2R3 0 1V DC CAL for full scale on the 0 1 scale c Rotate RANGE to 0 3 and change the cali brator output to 0 3 volt d Adjust A2R4 0 3 V DC CAL for 3 on the 0 3 scale e Rotate RANGE to 1 and changethe calibrator output to 1 volt f Adjust A2R5 1 V DC CAL for full scale onthe 0 1 scale ALTERNATE PERFORMANCE CHECKS AND CALIBRATION PROCEDURES 5 40 9 41 The following alternate procedures should be used only if the equipment in Table 5 1 is not avail able In each alternate procedure use an instrument of the specified accuracy If a less accurate instru ment is used the calibration ortest may not be within the Model 427A specifications To guarantee a specific accuracy use a standard at least four times more accurate than the Model 427A 5 42 AC CIRCUITS 5 43 Any test oscillator with low distortion lt 2 may be used as an ac voltage standard If the distor tion level is too high the calibration may be wrong as the 427A is an average responding rms calibrated meter The effects of harmonic distort
61. el 75 5841 4 lines Cable AMTRACO Seoul LEBANON Constantin E Macridis Clemenceau Street Box 7213 Beirut Tel 220846 Cable ELECTRONUCLEAR Beirut MALAYSIA Malaysia Ltd 2 Lorong 13 6A Section 13 Petaling Jaya Selangar Cable MECOMB Kuala Lumpur MOZAMBIQUE Goncalves LDA 4 1 Apt 14 Av D Luis Box 107 Lourenco Marques Cable NEGON NEW ZEALAND Hewlett Packard N Z Ltd 32 34 Kent Terrace Box 9443 Wellington N Z Tel 59 559 Cable HEWPACK Wellington PAKISTAN EAST Mushko amp Company Ltd Zirat Chambers 31 Jinnah Avenue Tel 280058 Cable NEWDEAL Dacca PAKISTAN WEST Mushko amp Company Ltd Oosman Chambers Victorla Road Karachi 3 Tel 511027 512927 Cable COOPERATOR Karachi PHILIPPINES Electromex Inc 2129 Pasong Tamo Makati Rizal P O Box 4326 Manila Tel 88 91 71 or 88 83 76 Cable ELEMEX Manila SINGAPORE Mechanical and Combustion Engineering Company Ltd 9 Jalan Kilang Singapore 3 Tel 642361 3 Cable MECOMB Singapore SOUTH AFRICA Hewlett Packard South Africa Pty Ltd House 43 Somerset Rd Cape Town Tel 3 6019 Cable HEWPACK Cape Town Telex 7038CT Hewlett Packard South Africa Pty Ltd Box 31716 30 De Beer Street Braamfontein Johannesburg Tel 724 4172 724 4195 Telex 0226 JH Cable HEWPACK Johannesburg TAIWAN REP OF CHINA Hwa Sheng Elect
62. ellwood Ill Automatic Metal Products Co Brooklyn N Y Worcester Pressed Aluminum Corp Worcester Mass Magnecrafl Electric Co Chicago Ill George Philbrick Researchers Inc Boston Mass Dania Fla Woodside N Y Long Island N Y Sheridan Wyo Bridgeport Conn Bloomfield N J Rolling Meadows 111 Allies Products Corp Continental Connector Corp Leecraft Mig Co Inc National Coil Co Vitramon Inc Gordos Corp Methode Mfg Code No 95566 95712 95984 95387 36067 96095 86256 96236 96306 96330 96341 96501 96508 96733 86881 97464 97539 97979 97983 98141 98159 98220 98278 38291 98376 98410 98731 98734 98821 98978 99109 99313 39378 99515 99707 99800 99848 99928 39934 99942 99957 Model 427A Manufacturer Address Arnold Engineering Co Marengo 111 Dage Electric Co Inc Franklin Ind Siemon Mig Co Wayne Ill Weckesser Co Chicago III Microwave Assoc West Inc Sunnyvale Calif Hi Q Div of Aerovox Corp Olean N Y Thordarson Meissner Inc Mt Carmel Solar Manufacturing Co Los Angeles Calif Microswitch Div of Minn Honeywell Freeport Ill Chicago Burlington Mass Oakland Calif Orchard Park N Y Carlton Screw Co Microwave Associates tne Excel Transformer Co Xcelite Inc San Fernando Elect Mfg Co San Fernando Calif Thomson Ind Inc Long Is N Y Industrial Retaining Ring Co Irving
63. espec tively Figure 3 1 Location of Front Panel Controls and Indicators 01791 2 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A Section III SECTION OPERATING INSTRUCTIONS 3 1 INTRODUCTION 3 10 OPTION 01 INSTRUMENT select either battery or line operation withthe 3 2 The Model 427A may be operated as a volt 2 i meter ac voltmeter ohmmeter or dB meter This hien 2 2 a 2 section contains operating instructions for each mode 2 ae 2 1 ES SES of operation b If line operation is selected the 115 230 3 3 FRONT AND REAR PANEL DESCRIPTION slide switch to indicate the proper line volt age 3 4 Figure 3 1 shows the location of all the Model 427A controls and indicators and explains function function During line operation the of each The Option 01 rear panel is shown The sap danad weaxenanclde Diank 1 5 MIN check position displays the output of the Option 01 power supply The reading 3 5 OPERATING INSTRUCTIONS should be 1 9 or higher on the 0 3 scale on any range indicating a power supply output NOTE of 15 volts or more This serves as a con venient check of the Option 01 power supply To obtain maximum battery life set the FUNCTION switch of OFF 3 11 DC MEASUREMENTS a Rotate the FUNCTION switch to DCV 3 6 MECHANICAL ZERO ADJUSTMENT DCV depending on th
64. ett Packard Co Palo Alto Calif 28520 Heyman Mfg Co Kenilworth J 30817 Instrument Specialties Inc Little Falls N J 33173 G E Receiving Tube Dept Owensboro Ky 35434 Leclrohm Inc Chicago 36196 Stanwyck Coil Products Ltd Hawkesbury Ontario Canada 36287 Cunningham W H amp Hill Ltd Toronto Ontario Canada 37942 P R Mallory 8 Co Inc Indianapolis ind 39543 Mechanical Industries Prod Co Akron Ohio 40920 Miniature Precision Bearings Inc Keene 42190 Muter Co Chicaga Ill 43990 Norgren Co Englewood Colo 44655 Ohmite Mfg Co Skokie IH 46384 Penn Eng 8 Mig Corp Doylestown Pa 47904 Polaroid Corp Cambridge Mass 48620 Precision Thermometer amp Inst Co Southamplon Pa 49956 Microwave amp Power Tube Div Wallham Mass 52090 Rowan Controller Co Weslminster Md 52983 Sanborn Company Waltham Mass 54294 Shallcross Co Selma N C 95026 Simpson Electric Co Chicago 111 55933 Sonolone Corp Elmsford N Y 55938 Raytheon Co Commercial Apparatus amp Systems Div So Norwalk Conn 56137 Spaulding Fibre Co Tonawanda N Y 56289 Sprague Electric Co North Adams Mass 59446 Telex Corp Tulsa Okla 59730 Thomas amp Betts Co Elizabeth J 60741 Triplett Electrical Inst Co Bluffton Ohio 61775 Union Switch and Signal Div of Westinghouse Brake Co Piltsburgh Pa 00015 48 Revised October 1969 Code No 62119 63743 64959 65092
65. for list of manu b Instrument serial number facturers c Description of the part d Manufacturer s part number d Function and location of the part DESIGNATORS assembly fuse MP mechanical part Tc thermocouple B motor FL filter plug vacuum tube neon BT battery HR heater Q transistor bulb photocell etc C capacitor IC integrated circuit QCR transistor diode Ww cable CR diode J jack R resistor X socket DL 7 delay line K relay RT thermistor XDS lt lampholder 05 lamp L inductor S switch XF fuseholder E mise electronic part M meter T transformer 2 network ABBREVIATIONS Ag silver ID inside diameter ns nanosecond s 1079 sl slide Al aluminum impg impregnated seconds SPDT single pole double A ampere s incd incandescent nsr not separately replace throw gold ins insulation ed able SPST single pole single throw C 7 capacitor un _ ceramic ja Fe Ms 5 o description 18 coef coefficient kHz kilohertz 10 hertz OD outside t TC temperature coefficient common ade TiO titanium dioxide comp composition L inductor k conn connection lin linear taper 7 ircuit tog toggle de _ log logarithmic taper tol tolerance deposited 12 trim trimmer DPDT double pole double uv pF picofarad s 10 m milli 10
66. gy Group is your source for quality new and certified used pre owned equipment FAST SHIPPING AND SERVICE CENTER REPAIRS WE BUY USED EQUIPMENT DELIVERY Experienced engineers and technicians on staff Sell your excess underutilized and idle used equipment TENS OF THOUSANDS OF at our full service in house repair center We also offer credit for buy backs and trade ins IN STOCK ITEMS www artisantg com WeBuyEquipment 4 EQUIPMENT DEMOS HUNDREDS OF Instra REMOTE INSPECTION LOOKING FOR MORE INFORMATION qii Remotely inspect equipment before purchasing with Visit us the web at www artisantg com 7 for more our interactive website at www instraview com 7 information on price quotations drivers technical LEASING MONTHLY specifications manuals and documentation RENTALS ITAR CERTIFIED Contact us 888 88 SOURCE sales artisantg com www artisantg com
67. he mea sured signal is incorrect the trouble is in either the DC Amplifier or the AC Post Attenuator 5 69 Monitor the signal at the collector of A2Q3 The signal should be 0 28 V rms 0 04 V If the measured signal is correct the AC Metering Circuit is functioning properly If not proceed with the following troubleshooting procedures 5 70 Check for dc voltage levels listed in Table 5 6 If a given reading is wrong the trouble is probably in that component or its associated circuit If A2CR3 A2CRA are replaced and the zero offset ACV FUNCTION is greater than 2 check the value of factory selected component A2R14 See Paragraph 5 72 and 5 77 Table 5 6 AC Metering Circuit Voltages NOTE The voltages listed in this table are nominal A tolerance of 10 should be allowed CHECK POINT VOLTAGE 2 1 A2Q1 Collector A2Q2 Emitter A2Q3 Collector 5 71 ADJUSTMENT OF FACTORY SELECTED COMPONENTS 5 72 Certain components within the Model 427A individually selected in order to compensate for slightly varying circuit parameters These compo nents are denoted by an asterisk on the schematic and the optimum or average value is shown The following paragraphs describe the function of each factory selected component and give instructions for their selection Normally these components do not need to be changed unless another associated compo nent is changed For example replacement of a transistor
68. in both positions 0 32 AC CALIBRATION 5 33 Three adjustments must be made to calibrate the ac circuits in the Model 427A First A2R17 ad justs the absolute amplitude calibration with a 10 mV 400 Hz input Then 2 3 is adjusted with a 10 mV 1 MHz input to calibrate the high frequency response Finally the frequency response of the AC Range At tenuator is set by adjusting C3 with a 3 V 100 kHz signal applied to the input 5 34 LOW FREQUENCY CALIBRATION a Connect the Model 427 as shown in Figure 5 1 and set 51 to position b Set the voltmeter calibrator output to 400 Hz at 0 01 volt rms and set the 427A RANGE to 0 01 and FUNCTION to ACV Adjust A2R17 400 CPS ADJ for exactly 0 01 volt indication on the 427A If the range of adjustment A2R17 is insufficient refer to Paragraph 5 81 0 35 HIGH FREQUENCY CALIBRATION a Connect the Model 427A as shown in Figure 5 1 5 5 Guaranteed 888 88 SOURCE www artisantg com Section V Set 51 to position Set 427A RANGE to 0 01 and FUNCTION to ACV b Set the oscillator to 400 Hz and adjust the output for exactly a 0 01 volt indication the 427A c Adjust the set level control REF SET on Test Oscillator for a convenient meter indi cation Record set level indication for use as a reference in step d d Adjust oscillator frequency to 1 MHz and adjust the amplitude vernier to the set level indication established in step c DO NOT readju
69. ing that the switch and withthe input terminals open ad battery voltage is 15 volts or higher If the just the DC ZERO Q thumbwheel for reading is below 1 5 replace the battery indication onthe ohms scale Pointer should according to the steps in Paragraph 5 54 rest on the mark just to the left of 01791 2 3 1 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Section III c Connect the unknown resistance across the OHMS and COM terminals Read the resis tance value on the ohms scale NOTE For best accuracy select an ohms range that will place the meter pointer near the center of the scale 3 13 AC MEASUREMENTS 3 14 The Model 427A responds to the average value of the ac input and is calibrated in rms volts for a sine wave input Since the average value and the rms value of a non sinusoidal signal are different any distortion on the input will affect the accuracy of the reading Table3 1 shows the effect of harmonic dis tortion on a reading NOTE The following table is uni versal in application since these errors are inherent in all average responding volt meters error shown above may vary with the phase relation ship between the harmonic and fundamental Table 3 1 Effects of Harmonic Distortion INPUT VOLTAGE TRUE RMS METER CHARACTERISTICS VALUE INDICATION eeru Fundamental 10 100 5 102 second harmonic
70. ion are dis cussed in more detail in Section III Paragraphs 3 14 and 3 15 5 44 Monitor the oscillator output with a recently calibrated rms voltmeter known to be four times as accurate as the Model 427A over the same band of frequencies rms voltmeter serves as a refer ence Each time the oscillator frequency is changed readjust the output for the reference The Model 427A ac calibration is based on a 400 Hz absolute refer ence so always start the ac calibration or perform ance checks at 400 Hz 9 45 RESISTANCE CIRCUITS 5 46 Ifa decade resistor is not available a selec tion of precisionresistors may be used The resistors should be at least 1 resistors andthe values selected should correspond to the RANGE settings hp part numbers for 1 resistors for each range given in Table 5 3 01791 3 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A Table 5 3 1 Resistors RESISTOR 1 hp PART NO 0757 0984 0757 0198 0757 0159 0757 0839 0757 0367 0698 3583 0698 3592 9 47 DC CIRCUITS 5 48 A precision dc voltage source is required for de calibration and performance checks Since the 427A is only calibrated on the 1 volt 0 3 volt and 0 1 volt ranges only three different voltages are needed 5 49 Amercury battery has good short term stability Connecta series voltage divider with a variable output acrossthe batte
71. it according to the procedures in Paragraph 5 25 If calibration is impossible then proceed with the troubleshooting steps 9 58 Check the instrument for obvious evidence of trouble such as loose or broken wires or broken connectors Check the printed circuit boards for cracks and separations and ensure that all connectors and pins are clean and tight 9 99 Isolate thetrouble to a particular circuit using the troubleshooting table Table 5 4 and the Theory of Operation Section IV Then refer to the Trouble shooting steps for that circuit in the following para graphs Table 5 4 Troubleshooting PROBABLE TROUBLE SYMP Battery ok no re Power Supply sponse to input Paragraph 5 o a ranges pegged DC offset circuit Check with no input ACV and A2CR1 Then check OHMS ok A1Q6 Nonlinear tracking on DC Amplifier Check voltage ranges 108 and associated circuit Check value of range resistors Check A1R14 and A1Q9 DC Amplifier See Paragraph 5 63 Constant upscale deflec tion on lower DCV ranges voltage at TP1 low Meter pegs on and OHMS ranges DC Amplifier check A1Q6 108 and A1Q9 See Paragraph 5 65 OHMS range always reads near zero DCV and ACV Range resistor in Figure 4 3 open Check R19 through R25 51 Range resistors Rp Figure 4 3 shorted Check R12 through R18
72. kard Australia Pty Ltd 61 Alexander Street Crows Nest 2065 New South Wales Tel 43 7866 Cable HEWPARD Sydney Telex 21561 Hewlett Packard Australia Pty Ltd 97 Churchill Road Prospect 5082 South Australia Tel 65 2366 Cable HEWPARD Adelaide Hewlett Packard Australia Pty Ltd 2nd Floor Suite 13 Casablanca Buildings 196 Adelaide Terrace Perth W A 6000 Tel 21 3330 CEYLON United Electricals Ltd Box 681 Yahala Building Staples Street Colombo 2 Tel 5496 Cable HOTPOINT Colombo CYPRUS Kypronics 19 190 Hommer Avenue Box 752 Nicosia Tel 6282 75628 Cable 1 ETHIOPIA African Salespower amp Agency Private Ltd Co 0 Box 718 i 58 59 Cunningham 51 Addis Ababa Tel 12285 Cable ASADO Addisababa HONG KONG Schmidt amp Co Hong Kong Ltd Box 297 1511 Prince s Building 10 Chater Road Hong Kong Tel 240168 232735 Cable SCHMIDTCO Hong Kong INDIA The Scientific Instrument Co Ltd 6 Tej Bahadur Sapru Road Allahabad 1 Tel 2451 Cable SICO Allahbad The Scientific Instrument Co Ltd 12 5 Dickenson Road Bangalore 1 Cable SICO Bangalore The Scientific instrument Co Ltd 240 Dr Dadabhai Naoroji Road Bombay 1 Tel 26 2642 Cable SICO Bombay The Scientific Instrument Co Ltd 11 Esplanade East Calcutta 1 Tel 23 4129 Cable SICO Calcutta The Scientific Instrument Co Ltd
73. l 5K 8870 Schematic Diagram 6 3 Figure 6 3 Section Model 427A 2 4 MP8 MP7 MP6 MPS MPI3 MPI4 MP20 MPI9 6 MPI8 5 MPI7 427 8 0540 OPTION OI ONLY Figure 7 1 Location of Mechanical Parts 01791 1 7 0 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A Section VII SECTION VII REPLACEABLE PARTS 7 1 INTRODUCTION 7 2 This section contains information for ordering replacement parts Table 7 1 lists parts in alpha meric order of their reference designators and indi cates the description hp part number of eachpart together with any applicable notes and provides the following 7 3 Miscellaneous parts are listed at the end of Table 7 1 Each factory selected component is keyed to paragraph describing the selection of the component value 7 4 ORDERING INFORMATION 1 5 To obtain replacement parts address order or inquiry to your local Hewlett Packard Field Office See Appendix B for list of office locations Identify a Total quantity used in the instrument T d y TQ parts by their Hewlett Packard part numbers column 7 6 NON LISTED PARTS b Description of the part See list of abbrevia tions below 7 7 To obtain a part that is not listed include Instrument model number c Typical manufacturer of the part in a five digit code See Appendix A
74. may require the changing of an associated factory selected component 5 73 A1R19 5 74 A1R19 adjusts the range of the BAL re sistor AIR15 If AMP BAL 1 15 cannot be ad justed properly after replacing transistor 106 1 R19 may need to be changed Use the following steps to select AIR19 a Set RANGE to 0 3 Set DC 2 adjustment to center and A1R15 to its center 01791 3 Guaranteed 888 88 SOURCE www artisantg com Model 427A Select the FUNCTION 0 or DCV which will produce an upscale deflection d If the FUNCTION selected is DCV increase the value of A1R19 if DCV is selected de crease A1R19 The value range of A1R19 15 0 to 18509 5 75 A2C2 5 76 A2C2 adjusts the range of the high frequency calibration capacitor A2C3 1 MC ADJ If during the high frequency calibration Paragraph 5 35 A2C3 can not be adjusted for the proper reading the value of A2C2 should be changed Ifthe reading is consistently high change the value of A2C2 to 47 pF If the read ing is consistently low remove 2 2 9 11 A2R14 5 78 A2R14 is factory selected to improve upscale meter tracking and correct any non linearity of diodes A2CR3 and A2CR4 If diode A2CR3 or A2CR4 re placed A2R14 may need to bechanged Use the pro cedure outlined in the following paragraph to select A2R14 5 79 If a zero offset greater than 2 two minor divisions
75. ms Operation 4 1 6 1 Introduction 6 1 4 9 AC Operation 4 1 4 12 Circuit 4 2 Section Page 4 13 DC Amplifier A1 4 2 REPLACEABLE 5 7 1 4 16 DC Offset 2 4 2 7 1 Introduction 7 1 4 19 AC Metering Circuit A2 4 3 1 4 Ordering Information 7 1 4 23 Battery Regulator Al 4 3 1 6 Non Listed Parts 7 1 Section Page Appendix V MAINTENANCE 5 1 5 1 Introduction 5 1 A CODE LIST OF MANUFACTURERS 5 3 Required Equipment 5 1 B SALES AND SERVICE OFFICES 9 5 Performance Checks 5 1 C MANUAL BACKDATING CHANGES LIST OF TABLES Number Page Number Page 1 1 1 0 5 3 1 5 7 3 1 Effects of Harmonic Distortion 3 2 5 4 Troubleshooting 5 1 3 2 DB Range Identification 3 2 0 5 Power Supply Voltages 5 8 5 1 Required Test Equipment 9 0 5 6 Metering Circuit Voltages 5 8 5 2 Resistance Accuracy 5 2 7 1 Replaceable 7 1 01791 2 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Table of Contents Model 427A LIST OF ILLUSTRATIONS Number Page Number Page 1 1 Model 427A Voltmeter 1 0 5 2 Resistance Accurac
76. n OHMS ATTENUATOR 427A RO Figure 4 3 AC RANGE ATTENUATOR DC AMPLIFIER FEEDBACK 427A ROA Model 427A DC AMPLIFIER FEEDBACK Ohms Operation AC POST ATTENUATOR AC METERING CIRCUIT AC FEEDBACK Figure 4 4 AC Operation 4 11 The AC Metering Circuitcontains both a feedback stabilizedac amplifier andan averaging meter circuit The meter circuit converts the ac signal to a dc volt age proportional to the average of the ac amplifier output A2R1 adjusts the current through the meter so that the scale reading is in rms volts 4 12 CIRCUIT DESCRIPTIONS 4 13 DC AMPLIFIER A1 4 14 Figure 6 3 is the schematic diagram of the Model 427A input to the DC Amplifier A1 is applied through Pin 2 to the impedance converter A1Q6 A field effect transistor is used as the impe dance converter because ofits characteristically high input impedance Transistors 107 and A1Q9 make up a two stage amplifier with A1Q9 as an emitter follower output stage The signal from the emitter of 199 is fed back to the base of A1Q7 for gain sta bilization 4 15 A1Q8actsasa constant current sourcefor A1Q6 The constant current from A1Q8 assures linearity in A1Q6 and helps minimize drift 4 2 4 16 DC OFFSET A2 4 17 The gate leakage from 196 Icsg amounts to a fraction of nanoamp This current is insignificant with the input shorted but with the input open it flows through the DC Ra
77. nge Attenuator resistance of 10 resulting in a few millivolts deflection on the lower ranges Consequently the meter indications with the input open and with the input shorted can be different When measuring across a low impedance flows mostly through the low impedance and this difference does not effect the measurement Unless is compensated for it will effect measurements made across high impedances gt 1 M 0 4 18 The DC Offset Circuit A2 see Figure 4 5 compensates for the leakage from 106 positive voltage tapped from A2R7 reverse biases A2CR1 The reverse leakage current from 2 1 Ig meets extremely high resistance at the gate of A1Q6 and passes through the much lower resistance of the at tenuator in a direction opposite to that of adjusting A2R7 can be set it and Iqgg cancel eachother The net voltage dropacrossthe attenuator 01791 2 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A 2 R6 TO EMITTER OF lt RESISTANCE lt ATTENUATOR lt IO MEGOHMS Y 2 0550 Figure 4 5 DC Offset Circuit would then be zero An alternative method of mini mizing the effects of Iggg would beto zero the instru ment with the impedance of the measurement source connected to the input terminals rather than with the input shorted A2C
78. nge Reading X10 X100 X1K X10K X100K 1 10 4 DC ACCURACY CHECK 2 of full scale 5 AC REJECTION CHECK 100 times full scale input lt 1 change 6 INPUT RESISTANCE CHECK 10 9 all ranges e INPUT CAPACITANCE CHECK 40pF 01 1votRange 3 300 volt Range 20 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A Section VI SECTION VI CIRCUIT DIAGRAMS with the switches flattened out The front of the in 6 1 INTRODUCTION strument is at the bottom of the page 6 2 This section contains the schematic diagram of the Model 427A and the circuit diagrams Figure 6 1 6 3 Figure 6 2 shows the layout of the two circuit shows the layout of both the FUNC TION and RANGE boards and the bottom view of the instrument Fig Switches The switches are viewed from the bottom ure 6 3 is the schematic diagram of the Model 427A REFERENCE DESIGNATIONS PARTIAL REFERENCE DESIGNATIONS ARE SHOWN PREFIX WITH ASSEMBLY OR SUBASSEMBLY DESIGNATION S OR BOTH FOR COMPLETE DESIGNATION COMPLETE ASSEMBLY SUBASSEMBLY COMPONENT DESIGNATION A2 NONE Q1 A2Q1 A2 A1 R1 A 2A1R1 NONE NONE 41 41 Assembly Reference Assembly Assembly Part Number Designation Name includes A2A1 subassembly not mounted on 4 4 Assembly 2 Connector mounted on Chassis or another Number indi
79. ngton Wis 00853 Sangamo Electric Co Pickens Div Pickens 00866 Engineering City of Industry Cal 00891 Car Holmes Corp Los Angeles Calif 00929 Microlab Inc Livingston N J 01002 General Electric Co Capacitor Dept Hudson Falls N Y 01009 Alden Products Co Brockton Mass 01121 Allen Bradley Co Milwaukee Wis 01255 Litlon Industries Inc Beverly Hills Calif 01281 TRW Semiconductors Inc Lawndale Calif 01295 Texas Instruments Inc Transistor Products Div Dallas Texas 01349 The Alliance Mfg Co Alliance Ohio 01538 Small Parts Inc Los Angeles Calif 01589 Pacilic Relays Inc Van Nuys Calif 01670 Gudebrod Bros Silk Co New York N Y 01930 Amerock Corp Rockford Ill 0196 Pulse Engineering Co Santa Clara Calif 02114 Ferroxcube Corp of America Saugerties N Y 02116 Wheelock Signals Inc Long Branch N J 02286 Cole Rubber and Plastics Inc Sunnyvale Calif 02660 Amphenol Borg Electronics Corp Broadview Ill 02735 Radio Corp of America Semiconductor and Materials Div Somerville N J 02771 Vocaline Co of America Inc Old Saybrook Conn 02777 Hopkins Engineering San Fernando Calif 02875 Hudson Tool amp Die Co Newark J 03508 Semiconductor Prod Dept Syracuse N Y 03705 Apex Machine 8 Dayton Ohio 03797 Eldema Corp Compton Calif 03818 Parker Seal Co Los Angeles Calif 03877 Transttron Electric Corp Wakefield Mass 03888 Py
80. nn United Transformer Corp New York N Y Oxlord Electric Corp Chicago 111 Bourns Inc Riverside Calif Acro Div of Robertshaw Controls Co Columbus Ohio FSC Handbook Supplements Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com CODE LIST OF MANUFACTURERS Continued Appendix A Code No Manufacturer Address 80486 All Star Products Inc Defiance Ohio 80509 Avery Labe Co Monrovia Calif 80583 Hammarlund Co Inc Mars Hill 80640 Stevens Arnold Co Inc Boston Mass 80813 Dimco Gray Co Dayton Ohio 81030 International Instruments Inc Orange Conn 81073 Grayhill Co LaGrange IH 81095 Triad Transformer Corp Venice Calif 81312 Winchester Elec Div Litton Ind Inc Oakville Conn 81349 Military Specification 81483 International Rectifier Corp Et Segundo Calif 81541 Electronics Inc Cambridge Maryland 81860 Barry Controls Div Barry Wright Corp Watertown Mass 82042 Carter Precision Electric Co Skokie Ill 82047 Sperti Faraday tnc Copper Hewitt Electric Div Hoboken N J 82116 Electric Regulator Corp Norwalk Conn 82142 Jeffers Electronics Division of Speer Carbon Co Du Bois 82170 Fairchild Camera amp Inst Corp Space amp Defense System Div Paramus N J 82209 Maguire Industries Inc Greenwich Conn 82219 Sylvania Electric Prod Inc Electronic Tube Division Emporium Pa 82376 Astron Corp East New
81. nteed 888 88 SOURCET www artisantg com l 1 3 6 7 S2E F FROM 7 9 n 2 6 14 926 MG 902 18 925 R7 DC OFFSET ADJ CRI 927 2 R6 20K 8 gt d DC AMPLIFIER amp BATTERY REGULATOR ASSEMBLY 00427 66501 2i 6 7 l IMPEDANCE 1 CONVERTER 2 1 FUNCTION RANGE FUNCTION Q6 1 1 S2C F 934 7 SID R 927 S2D R 5 12 0 A 43 9 7 13 6 7 15 8 RIO 2 2 2800 i 1 5 H 15 6 7 0 4 0 14 3 15 100 9 BAL 16 13 15 285 250 ASSEMBLY 2 667V UM SCREW 4 S2D F 956 95 S 12 4 0 RI 6 7 Q BAT TO R358 MI R SEE TABLE 5 5 FOR VOLTGE LEVELS 022 eh v R368MI 6 7 52 FROM lt 7 9 12 0 926 MG 902 oO DC OFFSET ae aos 5086 327 R6 20K 8 FENDER Re DC AMPLIFIER amp BATTERY REGULATOR ASSEMBLY 00427 66501 6 7 S2C R AMPLIFIER du io 6 7 9 o 7777 IMPEDANCE 1 CONVERTER ZERO Q00 4 DC OHMS 06 E AC POST sy amp 82 934 SID R 927 562
82. oup Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A Section V SECTION V MAINTENANCE 5 1 INTRODUCTION 5 2 This section contains information necessary to maintain the Model 427A The following paragraphs describe the Performance Checks the Calibration Procedures and the Troubleshooting Procedures 5 3 REQUIRED EQUIPMENT 5 4 Table 5 1 isa list of the equipment needed to properly maintain the Model 427A If the recommended model is not available use any substitute that meets the required characteristics 5 5 PERFORMANCE CHECKS 5 6 The Performance Checks in cabinet tests that compare the Model 427A with its specifications These procedures can be used both for incoming in spection and periodic inspection A Performance Check Test Cardis providedat the endof this section for recording the performance of the Model 427A during the performance checks The card canbe removed from the manual and used as permanent record of the incoming inspection or of a routine performance check If the Model 427A does not meet its specifi cations refer tothe Adjustment and Calibration Pro cedures Paragraph 5 25 5 7 AC ACCURACY AND FREQUENCY RESPONSE CHECK 5 8 The AC Accuracy and Frequency Response Check requires a test oscillator that is flat within 0 5 from 10 Hz to 1 MHz The absolute value of the ap plied voltage must be accurate within 40 2 hp Model 738B
83. p Chicago 111 Westinghouse Electric Semi Conductor Dept Youngwood Pa Ultronix Inc San Mateo Calif Union Carbide Corp Elect Div New York N Y Viking Ind Inc Canoga Park Calif core Electro Plastics Inc Cosmo Plastic Electrical Spec Co Barber Coiman Co Tiffen Optical Roslyn Heights Long Island N Y Westbury N Y Sunnyvale Calif Cleveland Qhio Rockford Metro Tel Corp Stewart Engineering Co Santa Cruz Calif Wakefield Engineering Inc Wakelield Mass Bassick Co Div of Stewart Warner Corp Bridgeport Conn Redwood City Calif Bausch and Lomb Optical Co Rochester N Y E T 4 Products Co of America Chicago Amatom Electronic Hardware Co Inc New Rochelle N Y Beede Electrical Instrument Co Inc Penacook N H Indianapolis Ind Phoenix 2 Raychem Corp General Devices Co Inc Components Inc Ariz Div Torrington Co West Div Van Nuys Calif San Carlos Calif Van Nuys Calil Pasadena Calif Minneapolis Minn Varian Assoc Eimac Div Kelvin Electric Ca Digitran Co Transistor Electronics Corp Westinghouse Electric Corp Electronic Tube Div Elmira N Y Filmohm Corp New York N Y Cinch Graphik Silicon Transistor Corp Avnet Corp Fairchild Camera amp Inst Corp Semiconductor Div Mountain View Calif Minnesota Rubber Co Minneapolis Minn Birlcher Corp The Monterey Park Calif
84. ring Co Inc Pico Rivera Calif CTS Corp Elkhart Ind Los Angeles Calif Burbank Calif Chicago ITT Cannon Electric Inc Cinema Div Aerovox Corp C P Clare amp Co Cenlralab Div of Globe Union Inc Milwaukee Wis Commercial Plastics Co Chicago Ill Cornish Wire Co The New York N Y Coto Coil Co Inc Providence Chicago Miniature Lamp Works Chicago Ill Cinch Mfg Co Howard B Jones Div Chicago Dow Corning Corp Midland Mich Electro Motive Mig Co Inc Willimantic Conn Dialight Corp Brooklyn N Y Indiana General Corp Electronics Div Keasby N J General Instrument Corp Cap Div Newark N J Drake Mfg Co Harwood Heights 11 Hugh H Eby Inc Philadelphia Pa Gudeman Co Chicago Elastic Stop Nut Corp Union N J Robert M Hadley Co Los Angeles Calif Erie Technological Products Inc Erie Pa Hansen Co Inc Princeton Ind Harper Co Chicago Helipot Div ol Beckman Inst Inc Fullerton Calif Hughes Products Division of Hughes Aircraft Newport Beach Calif Amperex Elect Co Hicksville L l N Y Bradley Semiconductor Corp New Haven Conn Electric Inc Hartford Conn Circle F Mfg Co Trenton N J George K Garrett Co Div MSL Industries Inc Philadelphia Pa Federal Screw Products lac Chicago Fischer Special Co Cincinnati Ohto General Industries Co The Elyria Ohio Goshen
85. rofilm Resistor Co Inc Cedar Knolls N J 03954 Singer Co Dieht Div Finderne Plant Sumerville J 04009 Arrow Harl and Hegeman Elect Co Harlford Conn 04013 Taurus Corp Lamberlville N J 04062 Arco Electronic inc Great Neck N Y 04217 Essex Wire Los Angeles Calif 04222 Hi Q Division of Aerovox Myrtle Beach S C 04354 Precision Paper Tube Co Wheeling 111 04404 Dymec Division of Hewlett Packard Co Palo Alto Calif 04651 Sylvania Electric Products Microwave Device Div Mountain View Calif 04673 Dakota Engr Inc Culver City Calil 04713 Motorola Inc Semiconductor Prod Div Phoenix Arizona 04732 Filtron Co Inc Western Div Culver City Calif 04773 Aulomalic Electric Co Northlake 04796 Sequoia Wire Co Redwood City Calif 04811 Precision Coil Spring Co El Monte Calif 04870 Motor Company Westchester 04919 Component Mfg Service Co W Bridgewater Mass 05006 Twentieth Century Plastics Inc Los Angeles Calif 00015 48 Revised Oclober 1969 Code No 05245 05277 05347 05397 05574 05593 05616 05624 05728 05729 05783 05820 06004 06090 06175 06402 06540 06555 06666 06751 06812 06980 07088 07126 07137 07138 07149 07233 07256 07261 07263 07322 07387 07397 07700 07829 07910 07933 07980 08145 08289 08358 08524 08564 08717 08718 08727 08792 08806 08984 09026 09134 Address Manufacturer Components Car
86. ronic Co Ltd P 0 Box 1558 Room 404 Chia Hsin Building No 96 Chung Shan North Road Sec 2 Talpei Tel 555211 Ext 532 539 545936 546076 548661 Cable VICTRONIX Taipei TANZANIA R J Tilbury Ltd Box 2754 Suite 517 518 Ambassadeur Nairobi Tel 25670 26803 68206 58196 Cable ARJAYTEE Nairobi THAILAND The International Engineering Co Ltd P Q Box 39 614 Sukhumvit Road Bangkok Tel 910722 7 lines Telex INTENCO BK 226 Cable GYSOM BANGKOK UGANDA R J Tilbury Ltd Box 2754 Suite 517 518 Hotel Ambassadeur Nairobi Tel 25670 26803 68206 58196 Cable ARJAYTEE Nairobi VIETNAM Peninsular Trading Inc Box H 3 216 Hien Vuong Saigon Tel 20 805 Cable PENINSULA Saigon ZAMBIA R J Tilbury Zambla Ltd Box 2792 Lusaka Zambia Central Africa FOR AREAS NOT LISTED CONTACT Hewlett Packard INTERCONTINENTAL 3200 Hillview Ave Palo Alto California 94304 Tel 415 326 7000 TWX 910 373 1267 Cable HEWPACK Palo Alto Telex 034 8461 E 1 70 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A MANUAL BACKDATING CHANGES MODEL 427A Appendix C VOLTMETER This manual backdating sheet makes this manual applicable to earlier instru ments Instrument component values that differ from those in the manual yet are not listed in the backdating sheet shoul
87. rumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A Section I SECTION GENERAL 1 1 DESCRIPTION 1 2 The Hewlett Packard Model 427A is aversatile compact self contained voltmeter It is capable of making dc measurements from 1 mV to 1000 volts ac measurements from 0 3 mV to 300 volts at frequencies from 10 Hz to 1 MHz and resistance measurements from 0 2 ohms to 500 megohms With the 01 option the Model 427A may be powered either by a 115 or 230 volt line or by an internal 22 1 2 volt dry cell battery 1 3 The use of solid state components throughout gives the Model 427A both ruggedness and reliability Battery operation makesthe instrument ideal for field use or isolation from common mode ground loops 1 4 Figure 1 1showsthe Model427A and Table 1 1 contains a list of the Model 427A Specifications 1 5 BATTERY 1 6 The battery used in the Model 427A is a 22 1 2 volt dry cell Eveready No 763 or an RCA 5102 Typical battery life is morethan 300 hours continuous operation or 700 hours intermittent operation 1 7 INSTRUMENT AND MANUAL IDENTIFICATION 1 8 Hewlett Packard uses two section serial num ber the first section serial prefix of the serial number on your instrument does not agree with those on the title page of this manual change sheets sup plied with the manual will define the differences be M ai
88. ry and monitor the output with a recently calibrated dc voltmeter knownto be four times as accur ate as the Model 427A Use this output to calibrate the 0 1 0 3 and 1 volt ranges 9 90 AC REJECTION 5 51 To check AC Rejection on 0 1 volt range oscillator with output of 10 volt peak to peak into 10 M ohms may be used If the hp Model 738BR Volt meter Calibrator is available a 400 Hz 10 volt peak to peak output may also be used to check the AC Re jection of Model 427A 9 92 INPUT IMPEDANCE CHECK 5 53 Measurethe resistance betweenthe VOLTS and COM terminals directly with the Model 427A Function Switch at DCV or DCV using an accurate ohmmeter Another Model 427A could be used for this purpose If an L C meter or capacitance bridge is available measure the input capacitance between the VOLTS and COM terminalsdirectly Be sure the Model 427A FUNCTION switch is in the ACV position 5 54 BATTERY REPLACEMENT 5 55 Figure 5 7 showsthe battery holder and the bat tery connections Turnthetwist lock fastener 1 4 turn counterclockwise tilt the battery and holder toward the rear ofthe instrument and lift out Replace the battery with an Eveready 763 RCA VS102 22 1 2 volt dry cell 427 0565 Figure 5 7 Battery Replacement 01791 3 Artisan Technology Group Quality Instrumentation Section V 5 56 TROUBLESHOOTING 9 97 Whenthe Model 427A operates improperly first adjust and calibrate
89. s Colorado Springs Colorado 000MM Rubber Eng amp Development Hayward Calif QOONN D Mfg Co San Jose Calif 000QQ Cooltron Oakland Calif 000WW California Eastern Lab Burlington Calif 000YY 5 Smith Co Los Angeles Calil From FSC Handbook Supplements Guaranteed 888 88 SOURCE www artisantg com Model 427A UNITED STATES ALABAMA Box 4207 2003 Byrd Spring Road S W Huntsville 35802 Tel 205 881 4591 TWX 810 726 2204 ARIZONA 3009 North Scottsdale Road Scottsdale 85251 Tel 602 945 7601 TWX 910 950 1282 5737 East Broadway Tucson 85716 Tel 602 298 2313 910 952 1162 CALIFORNIA 1430 East Orangethorpe Ave Fullerton 92631 Tel 714 870 1000 3939 Lankershim Boulevard North Hollywood 91604 Tel 213 877 1282 TWX 910 499 2170 1101 Embarcadero Road Palo Alto 94303 Tel 415 327 6500 TWX 910 373 1280 2591 Carlsbad Avenue Sacramento 95821 Tel 916 482 1463 TWX 910 367 2092 1055 Shafter Street San Dlego 92106 Tel 714 223 8103 TWX 910 335 2000 COLORADO 7965 East Prentice Englewood 80110 Tel 303 771 3455 910 935 0705 CANADA ALBERTA Hewlett Packard Canada Ltd 11745 Jasper Ave Edmonton Tel 403 482 5561 TWX 610 831 2431 CONNECTICUT 508 Tolland Street East Hartford 06108 Tel 203 289 9394 TWX 710 425 3416 111 East Avenue Norwalk 06851 Tel 203 853 1251 TWX 710 468 3750 DELAWARE
90. sistance accuracy precision resistances are needed Figure 5 2 shows the resis tance accuracy check using a General Radio Model 143227 Decade Resistor The resistance used should be accurate to within 0 5 and should have a range of 10 ohms to 10 M ohms a With the input open set the Model 427A FUNCTION to OHMS and the RANGE to X10 Adjust the DC ZERO Qe adjustment for an indication of on the meter face The needle should rest on the mark just to the left of b Connect the decade resistor and the Model 427A as shown in Figure 5 2 and set the decade for 10 9 427A meter should read within 5 of the known resistance one small scale divi sion one half small division d Repeat steps a through c using the RANGE and decade resistor settings listed in Table 5 2 DECADE RESISTOR GENERAL RADIO 14322 20 0 09 9 06 0 Model 427A NOTE DC 7 adjustment need only be made on the X10 and ranges Table 5 2 Resistance Accuracy Check 5 16 DC ACCURACY 5 17 The DC Accuracy Check requires a dc voltage standard that is accurate to within 0 2 of its indi cated output from 0 1 volt to 300 V The hp Model 738BR Voltmeter Calibrator is accurate to within 40 1 of the indicated output Figure 5 3 shows the test setup for the DC Accuracy Check a Set the Model 427A FUNCTION to DCV and the RANGE to 0 1 hp 427A VOLTMETER 4274 8 0533 Figure 5 2 Resis
91. ss US Rubber Co Consumer Ind amp Plastics Prod Div Passaic N J United Carr Fastener Corp Chicago Ill Bearing Engineering Co San Francisco Calif ITT Cannon Elect Inc Salem Div Salem Mass Connor Spring Mfg Co San Francisco Calif Miller Dial amp Nameplate Co El Monte Calif Radio Materials Co Chicago Augat Inc Attleboro Mass Dale Electronics Inc Columbus Nebr Elco Corp Willow Grove Wakefield Mass Redwood City Calif Gremar Mfg Co Inc K F Development Co Malco Mfg Co ine Chicago Ill Honeywell Inc Micro Switch Div Freeport 111 Nahm Bros Spring Co Oakland Calif Peabody Mass Rochester N Y Tru Con neclor Corp Elgeet Optical Co Inc Tensolite Insulated Wire Co Inc Tarrytown N Y Wesbury Long Island N Y Kearney N J IMC Magnetics Corp Hudson Lamp Co Sylvania Electric Prod Inc Semiconductor Div Woburn Mass Robhins amp Myers Inc Palisades Park N J Stemco Controls Div of Essex Wire Corp Mansfield Ohio Culver City Calif Livingston N J Waters Mfg Co G V Controls General Cable Corp Bayonne N J Phelps Dodge Yonkers N Y Raylheon Co Comp Div Ind Comp Operations Quincy Mass Scientific Electronics Products Inc Loveland Colo Wagner Elect Corp Tung Sol Div Newark N J Curtiss Wright Corp Electronics Div East Paterson N J South Chester Corp Chester Wire Cloth Products Inc B
92. st the set level control e Adjust A2C3 1 MC ADJ for exactly a 0 01 volt indication on the Model 427A 1f the range of adjustment 2 3 is insufficient refer to Paragraph 5 76 f Rotate 427A RANGE switch to 3 set S1 to position A Adjust the voltmeter calibrator for an output of 3 V at 400 Hz and record indication on 427A meter g Change 51 to position Set the oscillator to 400 Hz and adjust amplitude for 427A meter indication recorded in step f h Adjust the set level control REF SET for a convenient reference i Increase oscillator frequency to 100 kHz and readjust oscillator amplitude to set level reference established in step h j Adjust C3 3 V 100 kHz ADJ for exactly a 3 volt indication on the 427A 5 36 RESISTANCE INFINITY ADJUSTMENT 5 37 The resistance calibration is affected by the amplifier balance zero offset and regulator adjust ments Perform the steps in Paragraph 5 30 and 5 31 before makingthe resistance infinity adjustment Set FUNCTION to OHMS and RANGE to X10 b Short OHMSto COM and adjust theDC ZERO Qo for zero indication Open the input and adjust 1 18 X10 OHMS CAL for an o indi cation indicator should rest on the mark just to the left of o c Change RANGE to X1K short OHMSto COM and adjust DC 2 for zero indication Open the input and adjust 1 20 1 OHMS CAL for an indication 5 38 DC CALIBRATION 5 39 Adc voltage standard is n
93. tance Accuracy Check VOLTMETER CALIBRATOR hp 738BR hp 427A VOLTMETER 427A 8 0530 Figure 5 3 DC Accuracy and Linearity Check 01791 3 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Model 427A b Adjust the DC 7 for zero This ad justment need only be made on the 0 1 volt range Connect the voltmeter calibrator and the Model 427A as shown in Figure 5 3 Set the voltmeter calibrator output to 0 1 volts dc The Model 427A should read 0 1 volt 52 e Repeat steps a through e for each RANGE selection to 300 V by setting the voltmeter calibrator output to the full scale value for each range The Model 427A indication should not vary from the known input by more than 2 on any range 2 corresponds to 2 min or divisions on the 0 1 scale and 1 1 2 minor division on the 0 3 scale f Set the dc RANGE to 1000 V and the voltmeter calibrator to 300 V Model 427A should read 300 V 2 of full scale on the 1000 volt range Set the Model 427A to the 1 volt range and apply 0 9 0 8 0 7 0 6 0 5 0 4 0 3 0 2 and 0 1 volt de signals from the voltmeter calibrator In each case the reading should be within two minor divisions of the known input voltage h Set the Model 427A to the 3 volt range and apply 2 5 2 1 5 1 and 0 5 volt dc signals In each case the reading should be within 1 2 minor division on the 0 3 scale i Repe
94. tion Guaranteed 888 88 SOURCE www artisantg com 7 1 Section VII Model 427 Table 7 1 Replaceable Parts Cont d REFERENCE hp DESIGNATOR PART NO Q DESCRIPTION MFR PART NO 00427 66501 Assembly board DC Amplifier includes thru C6 Q1 thru Q9 CR1 thru CR5 R1 thru R21 1 0160 0170 1 fxd 0 22 uF 80 20 25 vdew 5 9 1 2 A1C3 0160 0168 2 fxd 0 1 uF 10 200 192 P10492 1 4 0150 0093 1 fxd 0 01 80 20 100 obd A1C5 0180 0224 1 fxd Al elect 10 uF 75 10 15 vdew 30D 106G015BA4 1 6 0180 1800 1 fxd Al elect 100 100 10 6 vdew Non polar 30D type obd 1 1 1901 0025 1 Diode Si 100 mA at 1V 100 piv 12 pF 1 2 1902 0568 1 Diode breakdown 6 2 V 5 DZ50801U 1 thru 1910 0022 5 Diode Ge HD1872 obd 1 5 101 1850 0111 2 PNP 2N404A 2N404A A1Q2 1854 0087 1 TSTR Si NPN 2N3417 2N3417 A1Q3 1854 0033 2 TSTR Si NPN 2 3391 2N3391 104 1850 0111 Ge PNP 2N404A 2N404A A1Q5 1854 0033 TSTR Si NPN 2N3391 2N3391 A1Q6 1855 0023 1 TSTR SU527 0527 107 1854 0057 4 TSTR Si 2N3855A 2N3855A A1Q8 1853 0036 2 TSTR Si PNP 2N3906 obd A1Q9 1854 0057 TSTR Si 2N3855A 2N3855A A1R1 0757 0198 1 fxd prec met flm 100 ohms 1 1 2 W CEC T O A1R2 0684 5611 1 R fxd comp 560 ohms 10 1 4 W CB5611 A1R3 0684 1541 1 fxd comp 150K 10 1 4 W CB1541 1 4 0757 0444 1 fxd prec met flm 12 1K 1
95. ton N J Automatic amp Precision Mfg Englewood N J Reon Resistor Corp Yonkers N Y Litton System Inc Adler Westrex Commun Div New Rochelle N Y R Troncis Inc Jamaica N Y Rubber Teck Inc Gardena Caiif Hewlett Packard Co Moseley Div Pasadena Calif Microdot Inc 50 Pasadena Calif Sealectro Corp Mamaroneck N Y Zero Mfg Co Burbank Calif Etc lac Cleveland Ohio General Mills Inc Electronics Div Minneapolis Minn Paeco Div of Hewlett Packard Co Palo Alto Calif North Hills Electronics Inc Glen Cove N Y International Electronic Research Corp Burbank Calif Columbia Technical Corp New York N Y Varian Associales Palo Alto Calif Atlee Corp Winchester Mass Marshall Ind Capacitor Div Monrovia Calif Control Switch Division Controls Co of America El Segundo Calif Delevan Electronics Corp East Aurora N Y Wilco Corporation Indianapolis Ind Branson Corp Whippany N J Renbrandt Inc Boston Mass Hoffman Electronics Semiconductor Div Monte Calif Technology Instrument Corp of Calif Newbury Park Calif THE FOLLOWING HP VENDORS HAVE NO NUMBER ASSIGNED IN THE LATEST SUPPLEMENT TO THE FEDERAL SUPPLY CODE FOR MANUFACTURERS HANDBOOK 0000F Maico Toot and Die Los Angeles Calif 00002 Willow Leather Products Corp Newark 7 000 England 000 Precision Instrument Components Co Van Nuys Calif 00005 Hewlett Packard Co Colorado Spring
96. w Edison Co Manchester 18042 Power Design Pacific inc Palo Alto Calif 18083 Clevite Corp Semiconductor Div Palo Alto Calif 18324 Signetics Corp Sunnyvale Calif 18476 Ty Car Mfg Co Inc Holliston Mass 18486 TRW Elect Comp Div Des Plaines HI 18583 Curtis Instrument Inc Mt Kisco N Y 18612 Vishay Instruments Inc Malvern 18873 E l DuPont and Co Inc Wilmington Del 1891 Durant Mig Co Milwaukee Wis 19315 The Bendix Corp Navigation amp Contro Div Teterboro N J 19500 Thomas A Edison Indusiries Div of McGraw Edison Co West Orange N J 19589 Baldwin Park Calif 19644 Electronics Horseheads N Y 19701 Electra Mig Co Independence Kansas 20183 General Atronics Corp Philadelphia Pa 21226 Execulone inc Long Island City N Y 21335 Bearing Co The New Britain Conn 21520 Fansteel Metallurgical Corp Chicago 111 23042 Texscan Corp Indianapolis Ind 23783 British Radio Electronics Ltd Washington D C 24455 G E Lamp Division Nela Park Cleveland Ohio 24655 General Radio Co West Concord Mass 24681 Inc Comp Div Huntington Ind 24796 Parelco Inc San Juan Capistrano Calif 26365 Gries Reproducer Corp New Rochelle N Y 26462 Grobet File Co of America Inc Carlstadt N J 26851 Compac Hollister Co Hollister Calif 26992 Hamilton Watch Co Lancaster Pa 217251 Specialities Mfg Co Inc Stratford Conn 28480 Hewl
97. y Check 5 2 1 2 11096A High Frequency Probe 1 1 5 3 DC Accuracy and Linearity Check 5 2 3 1 Location of Front Panel Controls 5 4 AC Rejection 5 3 and Indicators 3 0 5 5 Input Impedance Check 5 4 3 2 Impedance Correction Graph 3 3 5 6 Location of Internal Adjustments 5 5 4 1 Simplified Block Diagram 4 0 5 1 Battery Replacement 5 1 4 2 Operation ax 4l 4 3 Ohms Operation 4 2 6 1 Location of Switch Components 6 2 4 4 Operation 4 2 6 2 Component 6 3 4 5 DC Offset Circuit 4 3 6 3 Schematic Diagram 6 3 5 1 AC Accuracy and Frequency Response 5 0 7 1 Location of Mechanical Parts 1 0 E E J iv 01791 2 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com Section I o HEWLETT PACKARU O FUNCTION Model 427A 427A VOLTMETER RANGE SIT 5 pc 00 Figure 1 1 Model 427A Voltmeter Table 1 1 Specifications DC VOLTMETER Voltage Ranges 100 mV to 1000 V full scale 1 3 10 sequence 9 ranges Accuracy 2 of full scale on any range 0 C to 509C Input Resistance 10 megohms on all ranges AC Rejection Superimposed peak ac voltages 60 Hz and above 100 times greater thanfull scal

model 427a voltmeter - Artisan Technology Group

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