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HP 431-PowerMeter-1

1. e Pa No 0121 0055 0140 0204 0140 0280 0150 0012 0160 0174 0160 0185 0170 0069 0180 0049 0180 0059 0180 0105 0180 0106 0180 0158 0340 0086 0340 0090 0370 0064 0370 0067 0370 0104 851 16 431A 16G 431A 60A 431A 64A 4314 648 4318 16A4 4318 16C 4518 160 451 16 4218 16 4218 16 4318 16F 4318 16G 451B 16G 4518 19 4318 198 4518 19W 4318 65A 431B 95A 0510 0123 0683 1025 0683 2215 0683 2435 0683 2725 0683 3305 0686 1025 0686 1525 0686 5525 0686 7525 6 8 AIR 7 2 145 7 C FXD MICA 47 5 500VDCW C FXD MICA 200 PF 1 300VDCW C FXD CER 0 01 UF 20 1000VDCW C FXD CER 0 47 UF 80 20 25VDCW C FXD MICA 2100 PF 1 300VDCW C FXD POLY 0 1 UF 2 5OVOCW C FXD ELECT 20 UF 50VDCW C FXD ELECT 10 UF 100 10 25VDCW C FXD ELECT 50 UF 25VDCW C FXD ELECT 60 UF 20 6VDCW C FXD ELECT 100 UF 100 10 INSULATOR BLACK S sau site INSULATOR 2 HOLE OUTSIDE KNOB VERNIER KNOB ZERO KNOB POWER RANGE ASSY CABLE 5 THERMISTOR MOUNT ASSY CABLES INCLUDES 1251 0149 ASSY COIL CONCLUDES L1 RB SUPPORT BATTERY COVER BATTERY WIRING HARNESS WIRING HARNESS ASSY CABLE 20 THERMISTOR MOUNT ASS Y ASSY ASSY 55 ASSY ASSY ASSY ASSY ASSY ASSY CABLE 50 THERMISTOR MOUNT 486A CABLE 50 THERMISTOR MOUNT 37842 CABLE 100 THERMISTOR MOUNT 486 CABLE 100 THERMISTOR MOUNT 478A CABL
2. Vary line voltage from 103 to 127 vac 207 to 253 vac 18 vdc should not vary perceptibly 5 58 OSCILLATOR FREQUENCY ADJUSTMENT 5 59 If both 100 and 200 ohm thermistor mounts are tobeused interchangeably with the Model 431B the frequency of the 10 oscillator amplifier should be adjusted in the following sequence the 200 ohm mount procedure paragraph 5 61 then the 100 ohm mount procedure paragraph 5 62 If only one type of mount will be used with the power meter only the appropriate procedure is required 5 60 An oscilloscope and frequency counter are needed for these adjustments See table 5 1 Test Equipment for requirement A plastic alignment tool should be used for the adjustment of L101 to avoid core damage 5 61 200 OHM MOUNT The following procedure adjusts the 10 ke oscillator frequency when a 200 ohm thermistor mount is connected to the Model 431B a Connect the 200 thermistor mount and cable to the Model 431B set the MOUNT RES switch to 200 52 b Connect the frequency counter between the plus end of C125 and ground adjust L101 to give a frequency of 10 150 cps c Connect the oscilloscope to the base of Q108 and observe the feedback signal amplitude It should not exceed 12 mv peak to peak 5 62 100 OHM MOUNT The following procedure adjusts the 10 ke oscillator frequency when 2100 ohm thermistor mount is connected to the Model 431B a Connect the 100 ohm thermistor mount and cable to
3. 1 0 Block Diagram e os RF Circuit gt dv CES Metering Bridge Circuit y ux ded Nulling Circuit Synchronous Detector Differential Amplifier cia E Feedback Current Generator Meter Circuit DC Calibration and Substitution cosa 0 Regulated Power Supply 1 2 1 The Combining Case side SI 2 2 Steps to Place Instrument into Combining Case 2 2 2 3 Adapter Frame Instrument Combinations 2 2 2 4 Two Half Modules in Rack Adapter 2 3 2 5 Repackaging for Shipment d L t I ai CO CO WI CO I P gt Lf P WH PW 1 C Pw C DI NIN 3 1 Front and Rear Panel Controls and Indicators 3 2 11 Power Switch Arrangement 3 2 Turn On Nulling Procedure 3 3 3 3 DC Substitution Technique 3 4 3 4 Permanent Record Pei 9 5 3 5 Increased Resolution 3 6 5 1 Cover Removal 5 0 3 6 Leveler Setup pris 3 6 5 2 Top View Ay es 3 7 Monitor Control Systems Re sa 3 7 5 3 Power Meter Assembly EE es 3 8 Determining Insertion Loss or Gain 3 7 5 4 Power Supply 5 14 LIST OF TABLES Number Title Page 1 1 Specifications e a 1 1 1 2 Model 431B Thermistor ME 1 2 3 1 Voltmeter Readout to Power Multipliers 3 6 5 1 Test Equipment
4. RECORDER The RECORDER input is a grounded telephone jack for monitoring the current which operates the Model 431B meter DC CALIBRATION amp SUBSTITUTION This terminal permits application of known direct current to the rf bridge The power reading obtained with the accurately known dc power applied is then compared with the reading ob tained when rf power was applied The dc sub stitution technique is used both to calibrate the 431B and to increase the accuracy of power measurement LINE VOLTAGE The LINE VOLTAGE switch S is a two position slide switch that selects the mode ac operation The line voltage for which the instrument is set to operate appears on the slider of the switch A 15 100 slow blow fuse is used for both 115 and 230 volt operation Figure 3 1 Front and Rear Panel Controls and Indicators 01370 2 Model 4518 l E O 1 Connect thermistor mount and cable to the THERMISTOR MOUNT thermistor mounts and their frequency ranges are given in table 1 2 Model 431B Thermistor Mounts Note When possible the Model 431B should be zeroed and nulled with the power source to be measured connected to the thermistor mount Ifthis is not possible anda coaxial thermistor mount is used terminate the rf input into a 50 ohm load Power source should be off while zero and null setting the Model 431B Power Meter 2 Set MOUNT RES to match thermistor mount resistance 100 or 200 ohms
5. 3 Set RANGE to 01 MW 4 Set POWER to AC AC amp CHARGE lamp will glow If instrument is battery operated rotate POWER to BATTERY ON 5 Adjust ZERO control for 25 to 75 of full scale on meter 6 Rotate RANGE to NULL and adjust null screw driver adjust adjacent to NULL on RANGE switch for a minimum reading gt MOUNT RES E Section Figure 3 2 VERNIER ZERO 000 4318 POWER METER RANGE Mw 01 03 2 3 1 3 iO DAR 20 15 10 58 5 10 100 200f f 7 Repeat steps 5 and 6 until NULL reading is within NULL region on the meter Note If instrument is battery operated and you are not able to zero the meter orif meter pointer fluctuates rapidly battery needs recharging Refer to paragraph 3 11 8 Set RANGE switch to the power rangetobe used and zero set the meter with ZERO and VERNIER controls Note Zero setaccuracy of 0 5 of fullscalecan be obtained by zero setting the meter onthe most sensitive range 01 mw only and assumingthe meter is properly zeroed on less sensitive ranges For maximum accuracy zero set the meter onthe range to be used 9 Apply rf power at the thermistor mount and read power on Model 431B meter Power is indicated on the meter directly in mw or dbm Note This instrument is accurate to within 4300 Accuracy to 1 or better is possible using the dc substitution technique de Scribed in figure 3 3 See alsoparagrap
6. lt lt 5 1 5 2 Troubleshooting sod de 5 3 5 3 Power Supply DC Voltage Checks ea 5 5 5 4 Power Supply Ripple Checks 5 5 5 5 10 Oscillator Amplifier DC Voltage Checks 5 5 5 6 10 Amplifier DC Voltage Checks ex 2 55 5 7 DC Voltages in Squaring Circuit 5 5 5 8 Data for Calibration Tracking Accuracy Check seda X ou ow ovx yell Reference Designation Index 6 1 6 2 6 2 Replaceable Parts 6 8 6 3 Code List of Manufacturers 6 11 01370 3 111 Section I Mode1 4918 Figure 1 1 Figure 1 1 Mode1 431B Power Meter 1 0 01370 1 Model 4518 Section I Paragraphs 1 1 to 1 4 SECTION I GENERAL INFORMATION 1 1 DESCRIPTION 1 2 The e Model431B Power Meter with temper ature compensated thermistor mounts measures power from 10 microwatts 20 dbm to 10 milliwatts 10 dbm in the 10 mc to 40 gc frequency range Direct reading accuracy of the instrument is 3 of full scale Instrument specifications are given in table 1 1 1 3 The design of the Model 431Bandits thermistor mount results in almost complete freedom from measurement error caused by ambient temperature changes The instrument incorporates two self balancing bridges with one arm of each bridge being a thermistor The two matched thermistors both located within the mount are thermally coupled but Table 1 1 Instrument Type Automatic self balanc
7. 4 22 A simplified schematic diagram ofthe amplifier is shown in figure 4 6 The pulsating dc from the synchronous detector is filtered by C117 C118 C119 25V OUTPUT 1 0106 RI39 2 0107 I5K 18V Cii8 CI RIA RISO RECTIFIED N SYNCHRONOUS DETECTOR in R 44 RI43 5V 50 8 864 Figure 4 6 Differential Amplifier 01370 2 TO FEEDBACK CURRENT SQUARED GENERATOR 106 loc DC BIAS TO METERING BRIDGE FEEDBACK CURRENT GENERATOR FROM US 0107 COLLECTOR 0104 Q O sio2 _ 25V 18VDC 50 65 74 Figure 4 7 Feedback Current Generator and R140 amplified by Q104 and fed to both the feed back current squared generator Q106 figure 4 7 and feedback current generator Q107 Temperature com pensation and low emitter circuit resistance for Q107 are provided by Q105 Diode CR106 protects Q106 and Q107 from excessive reverse bias when Q104 is cut off 4 25 FEEDBACK CURRENT GENERATOR Q107 4 24 A simplified schematic diagram of the feedback current generator is shown in figure 4 7 The dc signal from the differential amplifier is applied to feedback current generator 0107 0107 has two functions 1 it 4 3 Section IV Paragraphs 4 25 to 4 35 METER MIO RECORDER 9102 1 5V FEEDBACK SQUA GENERATOR 9106 AMPLIFIER 18VDC Figure 4 8 Meter Circuit completes the metering loop to the metering bridge and 2 it operates i
8. Chicago lil Philadelphia Pa New York N Y No Chicago 111 New Butan Conn Hamilton Watch Co Hewlett Packard Co Receiving Tube Dept Lectronm inc Stanwyck Coil Products Lid Hawkesbury Ontario Canada P R Mallory Co inc Indianapolis Ind Mechanical Indust es Prod Akron Dhio Miniature Precision Beatiags Inc Keene N H Muter Co Chicago Norgren Co Engiewood Colo Ohnite Mfg Co Skokie Polaroid Corp Cambridge Mass Precision Thermometer Inst Co Southampton Pa Lexington Mass Westminster M Wallham Mass Selma Raytheon Company Rowan Cotttollet Co Sanborn Co Shallcross Mig Co Simpson Elactric Co Chicago IH Sonotone Corp Eimsford Raytheon Co Commercial Apparatus amp Systems Div So Norwalk Conn Spaulding Fibre Co tac Tonawanda N Y Sprague Electtic North Adams Mass Telex Inc St Paul Minn Thomas amp Belts Co Elizabeth N J Terplett Electrical 1051 Bluttton Ohio Union Switch and Signal Div Westinghouse Au Brake Co Pittsburgh Universal Electric Co Owosso Mich Ward Leanard Electric Co MI Vernon N Y Western Electric Inc Mew York Weston Inst Div of Daystrom Inc Newark N J Wittek Mig Co Chicago Ill Revere Wollansak Div Mina Mining amp Mtg Co St Paul Winn Allen Mtg Co Hartford Conn Allen Mfg Co Hartlotd Conn Altmetal Screw Product Co
9. Since the order of magnitude of this error is small 0 3 uwatt it need be minimized only on the two most sensitive ranges of the Model 431A B Power Meter Refer to the Model 8402A Power Meter Calibrator manual for procedure used to minimize this error 3 17 POWER METER ACCURACY OF 1 OR GREATER USING THE DC SUBSTITUTION METHOD 3 18 Highly accurate instruments are available for measuring direct current Thus where optimum accuracy is required there is considerable advantage in uSing a technique where the rf measurement is used only as a reference and the determination of rf power is based on precise dc measurements In general the technique involves a Applying rf power to the Model 431B inthe usual manner and noting the resulting meter indication for use as a reference b Removing the rf power and applying sufficient dc at the DC CALIBRATION amp SUBSTITUTION terminals to exactly duplicate the meter indication produced by the rf power Using the value of dc which duplicated the ref erence in calculating rf power 3 19 Although the dc substitution technique is the most accurate method of measuring rf power there are sources of error that must be considered The accuracy of the de substitution technique depends largely upon a how precisely the reference is duplicated TEMPERATURE COMPENSATED RF SOURCE THERMISTOR Section Paragraphs 3 17 to 3 26 b how accurately the value of the substituted
10. 09250 09569 10214 10411 10646 11236 11227 11242 11312 11534 11711 11717 11870 121 12697 12859 1298 12930 13103 13396 13835 14099 14193 14298 14493 14655 14960 15203 15291 15558 18272 15818 15309 16037 16352 15688 15758 17109 18476 18486 18583 18873 19315 19500 19201 Manufacturer Address Transistor Electronics Corp Minneapolis Minna Westinghouse Electric Corp Electronic Tube Div Filmohm Corp New York Cinch Graphik Co City of Industry Calif Avenel Corp Los Angeles Calit Fawchild Camera inst Corp Semiconductor Dis Mountain View Cail Minnesota Rubber Co Minneapolis Minn The Birtcher Corp Los Angeles Cali Technical Wwe Praducis inc Ciantord N J Continental Device Corp Hawthorne Calif Raytheon Mfg Co Semiconductor Div Shockley SemiConductor Laboratories Boonton Radio Corp U S Engineering Bunn Delbert Co Burgess Battery Co Miagara Fails Ontario Canada The Bristol Co Waterbury Conn Sloan Company Sun Valley Calif ITT Cannon Electric Inc Phoenix div Phoenix Arizona CBS Electronics Semiconductol Operations Div C 8 S Inc Lowell Mass Mel Rain Indianapolis tnd Babcock Reiays Div Costa Mesa Calif Texas Capacitor Co Housion Texas Atohm Etectranics Sun Valley Cali Electro Assemblies Inc Chicago Ill Mallory Battery Co of Canada Ltd Totooto Ontario Canada General Traosis
11. Connect the oscilloscope or ac vtvm between ground and the base of 0103 d Switch the Model 431B on and set RANGE to 10 MW e Adjust the ZERO control to maintain a meter indication of less than 5 of full scale on the Model 431B while adjusting L102 for a minimum indication on the oscilloscope or vtvm f Set RANGE to 01 MW and repeat step e this time maintaining an on scale meter indication on the Model 431B g Move the oscilloscope or vtvm connection from the base of Q103 to the lead of R138 nearest 103 h Adjust null capacitor C103 to minimize oscillo scope or vtvm indication Minimum indication should occur with the capacitor near the center of its range Note A decade capacitance box can be used to determine the value of capacitance to be added refer to table 5 1 i Set Model 431B RANGE switch to NULL Adjust the null capacitor C103 for a minimum indication on the Model 431B meter Minimum indication should occur at less than 4 of full scale and C103 should be near its mid range Note When only a 100 ohm thermistor mount will be used with the Model 431B the value of C104 may be changed to obtain the null re quirements specified above 9 68 200 OHM The following procedure is used to make coarse null adjustment when a 200 ohm therm istor mount is connected to the Model 431B a Set MOUNT RES to 200 0 Section V Paragraphs 5 69 to 5 74 b Set RANGE to 01 MW Connect the oscill
12. DIFFERENTIAL 4 ALL VALUES OHMS AND AMPLIFIER 0101 11 PICOFARADS UNLESS R101 103 105 ili 113 144 OTHERWISE INDICATED pore I 5 FRONT PANEL SJN l 20108 UC ENGRAVING B REAR PANEL lt J ENGRAVING RI44 UNASSIGNED RII2 e enda 6 ROTARY SWITCH OR TIO4 di iid O POTENTIOMETER RI43 7 ww DC 560 wm OKC jOKC ERROR SIGNAL B X VALUE SELECTED AT FACTORY UNREG AVERAGE VALUE SHOWN 9 01 VOLTAGE MEASURED WITH RESPECT 18V REG 2 TEST POINT COPYRIGHT 1962 BY NEWLETT PACKARD COMPANY 4518 PWR METER 3OIAB PAGE 2 ti Figure 5 3 Power Meter Assembly 5 13 9 p o SINS P O AIQI POWER METER ASSY _ _ 1 5V UNREG TO RI43 AND RI78 43 TO 0 l BLK RED GRN i 0L TO D l 8vrms 20UF L5V CAS CR6 1 31 3V 2 PA 115 VAC 10K LINE VOLTAGE DIFFERENTIAL AMPLIFIER I ce BLK 230v GRN 04 05 2N1304 1854 0003 OA SERIES 10 6MVrms BLK REGULATOR CONTROLS Sy ms ve 01 02 AMPLIFIER 3300 93 l RI E NISTO 2N1370 05 18v 33K REG Livems 5 ADJ AC 051 H E MAX 1800 Tcs 4 a 9 O UF 4700 CHARGE gt D IBV REG Do 2 X 25 6 o 24 0 25V UNREG oFF ac CHARGE i TO RI39 i BATTERY I I R
13. Large unbalance in the metering bridge C105 C104 10 kc amplifier failure Thermistor mount in strong rf field Interference from stray 10 signal Thermistor mount Meter not mechanically zero set Meter MOUNT RES switch Power supply Battery 10 ke amplifier Resistor collector Q101 Q107 Q106 Q102 Resistors emitter Q107 Q106 10 kc amplifier 5 23 STEP 1 a Connect the oscilloscope between the positive lead of C125 and ground check the 10 kc oscillator amplifier output amplitude and waveform Output amplitude with a 200 ohm thermistor mount con nected to the Model 431B should be 15 vac 20 peak to peak If a 100 ohm mount is used the amplitude should be 8 vac 20 peak to peak The waveform must be sinusoidal with only slight cross over distortion caused by Q110 and 9111 b Check the frequency of the oscillator amplifier If a Model 478A thermistor mount is used terminate the rf input to the mount in 50 ohms A Model 486A thermistor mount does not require termination Con nect the frequency counter between the positive lead of C125 and ground With Model 478A thermistor mount connected to the Model 431B the oscillator amplifier frequency should be 9750 10 000 cps With a Model 486A thermistor mount connected the fre quency should be 10 kc 50 cps 5 24 STEP 2 a Connect the oscilloscope between the base of Q108 and ground observe the amplitude of the feed back signal to the oscillator ampl
14. order by de TI titanium dioxide CONN connection scription TOG toggle CRT cathode ray tube IMPG impregnated i tolerance a E RIM trimmer DEPC deposited carbon INCD incandescent PC printed circuit TWT traveling wave tube BIA Tubes transi i INS insulation ed board I din Electronic PF picofarads micro 10 9 Industries Associa 5 PP VAC vacuum tion standards will LIN linear taper V p VAR variable normally result in ithmi n INVERSE W with instrument operating ds POR 22 w watts within specifications M 6 POS 7 porcelain WW wirewound tubes and transistors gt position s W O without s le milliamperes POLY polystyrene Witnou af perior mance willbe MINAT miniature POT potentiometer supplied if ordered A optimum value 5 by 3 stock numbers rectifier selected at factory i rotary average value ELECT electrolytic MTG mounting RMS root mean square shown part may ENCAP encapsulated MY mylar RMO rack mount only be omitted 01370 3 6 1 Section VI Model 431B Table 6 1 Table 6 1 Reference Designation Index Reference Designation Description 1101 cdi 101 4518 65 ASSY ETCHED CIRCUIT INCLUDES C1 THRU C6 R102 R103 C102 C106 8105 THRU R110 C110 THRU C125 R113 THRU R116 CR1 THRU CRO R125 THRU R140 CR101 THRU CR113 R142 THRU R149
15. resistance arm of the rf bridge 5 thatthe bridge will function with either a 100 or 200 ohm thermistor mount OKC BIAS TO METERING BRIDGE R Cb i 200 3 9200 3 mla l 2000 IND 1 4 aloon REI I SHIELDI FF i 5 0 1 10KC elo ee AMPLIFIER ERROR Figure 4 2 RF Circuit 4 1 Section IV Paragraphs 4 12 to 4 19 4 12 METERING BRIDGE CIRCUIT 4 13 simplified schematic diagram ofthe metering bridge circuit is shown in figure 4 3 Operation of the metering bridge circuit is similartothe r bridge cir cuit It uses the same principle of self balancing through a closed loop metering loop The major dif ference is that dc rather than 10 kc power is used to rebalance the loop The resistive balance point is adjusted by the ZERO and VERNIER controls which constitute one arm of the bridge The MOUNT RES switch not shown in figure 4 3 whichis mechanically linked to both the rf bridge and metering bridge changes metering bridge reference resistance from 100 to 200 ohms When the MOUNT RES switch is in the 200 ohm position some of the feedback current is shunted to ground through R101 This maintains the I2R function constant when mount resistance is changed from 100 or 200 ohms The switch also adds the necessary reactance for each position 4 14 The same 10 kc power change produced inthe rf bridge by rf power also affects the metering bridge through the series connection of T
16. 16A RETAINER INDICATOR LIGHT USED WITH 05 HEAT SINK TRANSISTOR CARTON CORRUGATED PAD FOAM See list of abbreviations in introduction to this section 01370 3 Model 431B Reference Desig 01370 3 ation Section VI Table 6 1 Table 6 1 Reference Designation Index Cont d Stock No Description OPTIONS OPTION 01 1420 0009 BATTERY RECHARGEABLE BT1 431A 54A SUPPORT BATTERY 431 648 COVER BATTERY 4318 95A RECHARGEABLE BATTERY INSTALLATION KIT OPTION 02 431A 16G ASSY CABLE SPECIAL PURPOSE INCLUDES 1251 0149 CONNECTOR FEMALE OPTION 10 4518 160 ASSY CABLE 20 THERMISTOR MOUNT FOR USE WITH HP MODEL 486A OR 478A THERMISTOR MOUNT OPTION 11 451B 16E ASSY CABLE 50 THERMISTOR MOUNT FOR USE WITH HP MODEL 486A THERMISTOR MOUNT OPTION 12 4318 16F ASSY CABLE 100 THERMISTOR MOUNT FOR USE WITH HP MODEL 486A THERMISTOR MOUNT OPTION 12 8518 1606 ASSY CABLE 200 THERMISTOR MOUNT FOR USE WITH HP MODEL 486A THERMISTOR MOUNT OPTION 21 451 16 ASSY CABLE 50 THERMISTOR MOUNT FOR USE WITH HP MODEL 478A THERMISTOR MOUNT OPTION 22 4518 16 ASSY CABLE 100 THERMISTOR MOUNT FOR USE WITH HP MODEL 478A THERMISTOR MOUNT OPTION 25 431B 16G ASSY CABLE 200 THERMISTOR MOUNT FOR USE WITH HP MODEL 478 THERMISTOR MOUNT See list of abbreviations in introduction to this section 6 7 Section V Table 6 2 Table 6 2 Replaceable Parts Model 431B
17. 431B is disconnected from the ac line b Connect the current meter to monitor the current in one of the leads between the battery terminals and the BATTERY and BATTERY terminals on the circuit board c Set the POWER switch to BATTERY ON and observe the reading on the current meter it should read 40 to 53 ma 5 45 CHARGING CHECKS 5 46 The following procedures test the recharge and trickle charge capability of the Model 431B A direct current meter see table 5 1 a 7500 ohm 1 2 watt resistor and a 780 ohm 1 3 watt resistor are re quired for these tests The battery is disconnected from the BATTERY and BATTERY circuit board terminals during both tests 5 47 TRICKLE CHARGE CURRENT The following procedure is used to check the trickle charge current applied to the battery when the power meter is operated from ac primary power a Connect the 7500 ohm 2 watt resistor between the BATTERY and BATTERY terminals of the circuit board b Connect the current meter to monitor the current through the resistor c Connect the Model 431B to the ac line set the POWER switch to AC and observe the reading of the current meter Trickle charge current should be 3 2 to 4 8 ma 5 48 CHARGE CURRENT The following procedure checks the current supplied for recharging the battery a Connect the 180 ohm 3 watt resistor between the BATTERY and BATTERY terminals of the circuit board b Connect the current meter t
18. Francisco Ca f Miller D at amp Nameplate Co Monte Calf Materials Co Chicago 1 Inc Allieboso Mass Dale Electronics Inc Columbus Nest E co Corp Willow Grove Pa Crema Mtg Co Inc Waselield Mass K F Development Co Redwood City Cali Honeywell Inc Micro Switch 01 Freeport 11 Oakland Calil Peabody Mass Rochesles N Y Nahm Bios Soung Co Tiu Connector Corp E geet Optical Co Inc Universa industries Inc City of Industry Calf Tensolite Insulated Wire Co Inc Tanytown N Y Sylvan a Electuc Prod Inc Seruconducier Dev Woburn Mass Code No 33365 233 23 88 32825 31 3 94144 94149 94154 94 57 94222 54310 91337 31567 95023 95736 95255 95763 85264 45765 95275 95348 35334 35712 95987 96667 96095 96256 96296 96330 95341 96501 97464 97539 91979 97983 9814 98153 98223 98278 98291 98405 CODE LIST OF MANUFACTURERS Continued Manufacturer Address New York N Y Mansfield Ohio Port Monniouth N J Livingston N J Bayonne N Robbins and Myeis Inc Stevens Mig Co Inc Howard J Smith Inc S V Controls Genera Cable Corp Raythega Co Comp ad Come Operations Quincy Mass Scientilic Electromes Products Inc Loveland Colo Teng Sol E ectic inc Newark N J Cutliss Weight Corp Elecltenics Div South Crester Corp T in Ohm Pindne s Mercar Components Div Huatiagton 100
19. Inc Garden City N Y Atlantic india Rubber Works Inc Chicago Mi Co Inc Union City N J Belden Mig Co Chicago BI Bird Electronic Cotp Cleveland Ohio Birnbach Radio New York N Y Boston Gear Works Div of Murray of Texas Bud Radio Inc Witloughdy Ohio Camloc Fastener Corp Paramus Cardwell Condenser Corp L indenturst L 4 N Y Bussmann Mig Div of McGraw Edison Co Chicago Condenser Corp Calif Spring Co Inc CTS Corp ITT Cannon Elecluc Inc Cinema Engineering Co C P Clare amp Co Centralab Div Globe Union Inc Milwaukee Wis Chicago 111 New Yaik N Y Chicago IH Quincy Mass St Louis Mo Chicago lil Picc Rivera Calil Elkhart Ind Los Angeles Calif Burbank Calf Chicago Wl Commercial Plastics Co The Cornish Wire Co Chicago Miniature Lamp Works 0 Smith Corp Crowley Div West Grange N Cinch Mfg Co Howard 8 jones Div Chicago 11 Dow Corning Corp Midiand Mich Electro Molive Mig Co Inc WHtiemantic Conn Coto Coll Co inc Providence Jahn E Fast Co Div Vicloreen instr Co hicago Qualight Corp Brooklyn NY indiana General Corp Electronics Dtv Keasby N J Drake Mig Co Chicago MI 77825 12928 72964 72982 1108 13076 73138 13293 73445 13506 13559 23682 13134 13143 13793 73846 73899 73905 74276 74455 7486 14868 74970 15042 75373 15382 7581
20. MW ranges power is read in the same way as when the arrangement shown in figure 3 5 is used decimal placement being determined by the setting of RANGE On the 03 3 and 3 MW ranges however to obtain the power readings the voltmeter indication must be multiplied by the factor given in table 3 1 Table 3 1 Voltmeter Readout to Power Multipliers 03 MW 0 0316 3 0 316 3 3 16 3 28 LEVELER Figure 3 6 is a block diagram of a closed loop control circuit for maintaining output power at a constant level It is recommended for use in leveling the output of various types of p microwave equipment such as bwo sweep oscillators twt micro wave amplifiers and rf generators In additionto the Model 431B and its thermistor mount such a leveling system requires the 01 8401 Leveler Amplifier and a directional coupler with good directivity suchas one of the 0 752 series of waveguide couplers or 770 Series of coaxial couplers The output of the power Source is sampled by the coupler and applied to the Model 431B A dc signal proportional to the power sample is fed from the Model 431B RECORDER jack to the Leveler Amplifier In the H01 8401A the signal from the Model 431B is compared to an internal ref erence voltage and the difference is amplified and fed back as a controlvoltageto hold output power constant 3 29 MONITOR CONTROL SYSTEMS By addinga dc amplifier and relay circuittothe rf monitoring arm of a system the dc s
21. Ri66 38 05K A FEEDBACK CURR GENERATOR Q107 1854 0003 25 UNRE SYNCHRONOUS DETECT RISI 5 3RD R132 3300 POWER METER ASSEMBLY AMPLIFIER 0103 2 1370 OF 1 FOR THIS Section V Figure 5 3 1 1 I ZETA RISO Ri67 10 46vu RI73 1 194 lop 82 09K 18 710 307 57 46K RIG ES o Ri68 9 64v 0 1 1 DA CRII2 RI75 t XRI63 REG 1 l i 6730 i 29 SEN i LJ i i TRIGA RI76 Loa I RITO t4 47VU s Mares 46 67K 4 39vl 42 y 1 i o RITI c ACRII0 8177 J i J XRI66 I 12 52V 1 1 38 05K 41 46K 12 48V 256 8K l if 1 1 1 R172 69 o 1103 Moi 52 3K CRIOS A ovo 25 ES 1 RIOS FEEDBACK S GURRENT MNA RECORDER FEEDBACK CRIO7 ir SENERA ica 854 0045 1 FEEDBACK CURRENT GENERATOR T RIB Q107 1000 1854 0003 4 R 39 15 25V UNREG NOTES 18V REG I DC VOLTAGE LIMITS GIVEN AT REFERENCE DESIGNATORS POINTS THRU THERMISTOR MOUNT 15 ATOI CONNECTED TO THE 4318 CIOI JO6 125 FOR THESE MEASUREMENTS 0 13 2 L CHASSIS GROUND 3101 102 103 LIOI 105 3 y CIRCUIT BOARD COMMON
22. at DEVICES hp 478A 4854 10000 80 5 255 RF SOURCE coupLeR PH LOAD Figure 3 7 Monitoring Control Systems RF TEMPERATURE RECORDER sii wicrowave COMPENSATED pod ee I THERMISTOR METER MOUNT i 418A 486A SWEEP X OUTPUT INPUT 80 256 Figure 3 8 Determining Insertion Loss or Gain 01370 2 Section IV Model 431B Figure 4 1 ax uer Adm 1 DC CALIBRATION i 8 SUBSTITUTION a ato Iiokc I 1 IOKC OSCILLATOR AMPLIFIER DETECTION 0108 Qitt THERMISTOR 1 F microwave DE POWER Ro LEGEND RES SO lo Sow lt J 0KC SYNCHRONOUS j AMPLIFIER DETECTOR l 2 101 0103 CR101 CRIO4 VLA 18 4 Rc c f NULL t ADJ DIFFERENTIAL a 4 AMPLIFIER 0104 0105 FEEDBACK CURRENT GENERATOR 0107 CURRENT CONTROL VERNIER FEEDBACK 7102 CURRENT uS 52 GENERATOR Iw y 0106 R18 115 230V AC 50 1000CPS OR 24V DC OPTIONAL BATTERY 1 5V DC 18V DC REG 25V DC REG REGULATED POWER SUPPLY 9D 3208 Figure 4 1 Block Diagram 4 0 01370 2 Model 431B Section IV Paragraphs 4 1 to 4 11 SECTION IV THEORY OF OPERATION 4 1 OVERALL DESCRIPTION 4 2 Figure 4 1
23. de substitution method dc is used to duplicate the rf power reading An accurate known current 146 is supplied externally at the DC CALIBRATION and SUB STITUTION terminals Calculation of the substituted dc power gives an accurate measure of the rf power Effectively dc power is substituted for rf power 4 33 REGULATED POWER SUPPLY 4 34 A simplified schematic diagram of the power Supply is shown in figure 4 10 The power supply operates from either a 115 or 230 volt 50 to 1000 cps ac source or from an optional 24 volt 30 ma rechargeable battery Three voltages andtwo current outputs are provided by the power supply Regulated voltages of 18 and 25 vdc and unregulated 1 5 vde operate the power meter circuits The current outputs are used for maintaining battery charge trickle charge for recharging the battery 4 35 18 vdc is regulated by a conventional series regulator 01 through Q5 The 25 vdc is developed across CR9 a 6 8 volt zener diode refer enced at 18 vdc The unregulated 1 5 vdc is taken 01370 1 Model 431B across the series diodes CR5 and CR6 The 18 vdc supply is adjusted by R13 4 36 POWER SWITCH 4 37 A simplified schematic diagram of the power switching arrangement is shown in figure 4 11 The power switch 52 has four positions OFF AC BATTERY ON and BATTERY CHARGE In the AC position the instrument operates from the conven tional line voltage if a battery has been installed i
24. figure 4 2 The rf bridge circuit consists of the rf bridge and 10 kc oscillator amplifier bridge includes thermistor the secondary winding of T101 resistors R102 and R103 the MOUNT RES switch 5101 and capacitance represented by and Cp The rf bridge and 10 kc oscillator amplifier are connected ina closed loop the detection loop which provides regenerative feedback for the oscillator amplifier This feedback causes the 10 oscillator amplifier to oscillate 4 9 When the power meter is off thermistor Ra is at ambient temperature and its resistance is about 1500 ohms the rf bridge is unbalanced When the power meter is turned on this unbalance of the rf bridge causes a large error signal to be applied to the 10 oscillator amplifier Consequently maximum 10 ke bias voltage is applied to the rf bridge As this 10 kc voltage biases R to its operating resistance 100 or 200 ohms the rf bridge approaches a state of balance and regenerative feedback diminishes until there is just sufficient 10 kc bias power to hold Rg at operating re sistance This condition is equilibrium for the detection loop 4 10 With application of rf power thermistor Ry s resistance decreases causing the regenerative signal from the rf bridge to decrease Accordingly 10 kc power diminishes the thermistor returnstooperating resistance and the detection loop regains equilibrium 4 11 MOUNT RES switch 5101 changes the
25. first three digits of the serial number on your instrument do notagree with those on the title page of this manual consult the Ap pendix for information regarding manual changes 01370 3 Model 4518 Section Paragraphs 2 1 to 2 8 SECTION INSTALLATION 2 1 INSPECTION 2 2 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 check for supplied accessories and test the electrical performance of the instrument using the procedure outlined in paragraph 5 71 If there is damage or deficiency see the warranty on the inside rear cover of this manual 2 3 INSTALLATION 2 4 The Model 431B is fully transistorized there fore no special cooling is required However the instrument should not be operated where the ambient temperature exceeds 55 140 F 2 5 RACK MOUNTING 2 6 The Model 431B is a submodular unit that when used alone can be bench mounted only However when used in combination with other submodular units it can be bench and or rack mounted The combining case and adapter frame are designed specifically for this purpose DIVIDER LATCH 2 7 COMBINING CASE The combining case isa full module unit which accepts varying combinations of submodular units Being a full modu
26. the Model 431B and set MOUNT RES to 100 9 b Connect the frequency counter between the posi tive end of C125 and ground The frequency should be 10 KC 50 cps If it is not proceed with step c Substitute values of capacitance for C101 until the frequency is within the limits of step b Note A decade capacitance box can be used to de termine proper value of capacitance that must be used See table 5 1 01370 2 Section V Paragraphs 5 56 to 5 68 9 63 COARSE NULL ADJUSTMENT 5 64 If both 100 and 200 ohm thermistor mounts are to be used interchangeably with the Model 431B the coarse null adjustment should be made in the following sequence the procedure in paragraph 5 67 first and then the procedure in paragraph 5 68 5 65 If only a 200 ohm thermistor mount is be used with the power meter follow the procedure of para graph 5 68 When only a 100 ohm thermistor mount is to be used the procedure of paragraph 5 67 is sufficient 5 66 An oscilloscope or ac vtvm is needed for these adjustments See table 5 1 Test Equipment for requirements A plastic alignment tool should be used for the adjustment of L102 to avoid core damage 5 67 100 OHM MOUNT The following procedure is used to make coarse adjustment of the null when a 100 ohm thermistor mount is connected to the Model431B Set MOUNT RES to 100 b Observe the arrangement and travel of null capacitor C103 then mechanically center C103 c
27. the voltage is measured across 1000 ohms This current is Iac Calculate power in mw from the expression 2 Dac R Power MW 5 4 10 where operating resistance of the term istor 100 or 200 ohms and I de substitution current in milliamps from step 6 To minimize error due to drift in either the reference or substituted power level steps 1 through 6 should be repeated Figure 3 3 DC Substitution Technique 01370 2 Model 4518 c Instrument Error This is the inability of the power meter to accurately measure and interpret the information available at the thermistor element In specifying the accuracy of a power meter instrument error is the figure usually given For the Model 431B instrument error is 3 of full scale 20 C to 35 C This error can be reduced by special techniques such as the dc substitution method discussed in para 3 17 d Error Due to the Unilateral Properties of a Thermistor The thermistor used in conjunction with the Model 431A B exhibits unilateral properties which when the source of power is a dc current causes a slightly different indication of power than is obtained by the calculation of 12R Thus the de power required to produce a reading on the Model 431A B Power Meter is not the same as the rf power required to produce the same reading on the Model 431A B Power Meter The maximum error produced from this source of error is 40 5 uwatts typical error is 0 1 uwatt
28. 0180 0049 CsFXD ELECT 20 UF 5OVDCW CRI THRU CRE 1901 0025 DIODE SILICON 50 1V 100 PIV 5 AND CR6 1901 0026 DIODE SILICON CRI 1902 0017 DIODE SILICON AVALANCHE CRB 1902 0018 DIODE SILICON AVALANCHE 1N941 CRI 1902 001 i DIODE SILICON AVALANCHE R10 TH CR100 NOT ASSIGNED 101 THRU CR104 1910 0016 DIODE GERMANIUM 100 MA 1V 60 PIV E S z See list of abbreviations in introduction to this section 01370 3 Model 4918 Table 6 1 Reference Designation Index Cont d Reference Stock No Description CR105 1901 0025 DIODE SILICON 50 MA 1V 100 PIV CR106 1901 0025 DIODE SILICON 50 1 100 PIV CR107 THRU CR113 1901 0024 DIODE SILICON 051 1450 0048 LAMP NEON NE2H Fl 2110 0017 FUSE CATRIDGE 0 15 J1 1251 0148 CONNECTOR POWER MALE 3 J2 THRU J100 NOT ASSIGNED J101 1251 0149 CONNECTOR FEMALE 6 CONTACT J102 1251 0066 JACK TELEPHONE FOR 2 CONNECTOR PLUG J105 DC CALIBRATION amp SUBSTITUTION CONSISTS OF 5060 0632 BINDING POST BLACK 5060 0633 BINDING POST RED 0340 0086 INSULATOR BLACK 0340 0090 INSULATOR sBLACK 2 HOLE OUTSIDE LI NSR PART OF Z1 L2 THRU L100 i NOT ASSIGNED 101 9140 0122 COIL VAR 2 WINDINGS 9 20 UM EACH L102 9140 0122 COIL VAR 2 WINDINGS 9 20 UH EACH L103 THRU L105 9110 0040 INDUCTOR AUDIO 2 5 MH M101 1120 0311 METER CALIBRATED P1 NSR PART OF 1 P2 NSR PART OF W1 91 1850 0
29. 02A OUTPUT CURRENT to ON note and record the Model 431B percent of power reading error 1 7 division on 0 3 meter scale i Repeat steps b through h for all Model 431B RANGE positions j Connect a decade resistance box across R179 see figure 5 2 k Select the resistance value which equalizes the maenitude of the largest positive and negative percent error m Remove the decade resistance box and replace with a resistor of the value selected in step k n Check all Model 431B RANGE positions Test limits the Model 431B full scale power reading error must not exceed 3 at ambient temperatures of 20 C to 35 C on all range positions refer totable 5 8 5 71 PERFORMANCE CHECK 5 72 The tests described below which verify that the Model 431B meets specifications use only panel con trols and connectors These tests can be used for in coming quality control for routine preventive main tenance and after repair A thermistor mount must be connected to the Model 431B for the performance checks though no power will be applied Note If there is possibility of rf pick up the ther mistor mount should be appropriately shielded 5 13 Check the mechanical zero set of the Model 431B meter according to paragraph 5 54 5 74 ZERO CARRY OVER CHECK a Set Model 431B RANGE to 01 MW 01370 2 Model 4518 b Adjust ZERO and VERNIER controls to set the meter pointer over the zero calibration mark c Rota
30. 065 TRANSISTOR GERMANIUM 2 152570 92 1850 0065 TRANSISTOR 2N1183 Q3 1850 0065 TRANSISTOR GERMANIUM 2N1370 94 1851 0017 TRANSISTOR GERMANIUM 281504 95 1854 0003 TRANS ISTOR SILICOM Q6 THRU 9100 ASSIGNED 9101 1850 0065 TRANSISTOR GERMANIUM 2N1370 910 1851 0017 TRANSISTOR GERMANIUM 2N1304 0105 THRU 810 1850 0065 TRANSISTOR GERMANIUM 2N1370 9106 1854 0045 TRANSISTOR SILICON Q107 1854 0003 TRANSISTOR SILICON 9108 1850 0065 TRANSISTOR GERMANIUM 2 812570 Q109 1851 0017 TRANSISTOR GERMANIUM 2N1304 9110 1850 0040 TRANSISTOR 2N583 0111 1851 0024 TRANSISTOR GERMANIUM 2N388A RI 0687 3331 R FXD COMP 33K OHM 10 1 2W R2 0687 3321 R FXD COMP 3 3K OHM 10 1 20 R3 0690 5911 R FXD COMP 590 OHM 10 1 R amp 0690 1221 R FXD COMP 1 2 OHM m R5 687 4721 R FXD 4 7K OHM 10 1 2W R6 0687 2711 R FXD COMP 270 OHM 10 1 2W R7 0687 3321 R FXD COMP 3 3K OHM 10 1 2w R8 NSR PART OF Z1 R9 0687 4721 R FXD COMP 4 amp 7 OHM 10 1 24 R10 0687 5521 R FXD COMP 3 3K OHM 10 1 2 gt A e See list of abbreviations in introduction to this section 01370 3 Section VI Table 6 1 Section VI Table 6 1 Reference Desig 11 R12 R13 R14 R15 R100 OPT R102 R103 OPT OPT OPT OPT R105 OPT OPT OPT R106 OPT OPT OPT OPT R107 R106 109 R110 ation THRU 10 21 12 21 25 10 11 21 12 22 15 25 1
31. 1 21 12 22 15 25 11 21 12 22 15 25 10 11 21 12 22 15 25 R111A B R112 R115 R114 R115 R116 R117 R118 R119 R120 R121 R122 R123 R124 R125 R126 6 4 Model 431B Table 6 1 Reference Designation Index Cont d fj Stock No 0687 1821 0758 0006 2100 0182 0758 0005 0727 0595 0727 0483 0727 0484 0727 0485 0727 0486 0811 0051 0811 0096 0811 0085 0811 0086 0811 0087 0811 0051 0811 0099 0811 0088 0811 0089 0811 0090 0811 0065 0811 0094 0811 0095 0811 0112 0811 0101 0811 0064 0811 0091 0811 0098 0811 0092 0811 0095 0811 0065 0811 0066 0758 0020 0811 0065 2100 0342 0686 7525 0686 5525 0686 2725 0685 5525 0683 4315 0683 3305 0683 7505 0683 2215 0683 1025 0683 2435 0683 9115 0683 2725 0686 1025 0686 1525 Description Note R FXD COMP 1 8 OHM 10 1 2W R FXD MET FLM 10K OHM 5 1 2 R VAR COMP 3 3K OHM 10 LIN 1 3W R FXD MET FLM 4 7K OHM 5 1 2W NOT ASSIGNED R FXD DEPC 316 OHM 1 2 1 2w R FXD DEPC 518 1 OHM 1 1 2W R FXD DEPC 320 1 OHM 1 1 2W R FXD DEPC 323 4 OHM 1 1 2W R FXD DEPC 329 8 OHM 1 1 2W R FXD WW 200 3 OHM 0 1 1 4W R FXD WW 200 7 OHM 0 1 1 4W R FXD WW 201 5 OHM 0 1 1 4W R FXD WW 203 3 OHM 0 1 1 4W R FXD WW 207 1 OHM 0 1 1 4W R FXD WW 200 3 OHM 0 1 1 4W R FXD WW 202 5 OHM 0 1 1 4W R FXD WW 206 6 OHM 0 1 1 4W R FXO WW 215 0 OHM 0 1 1 5W R FXD WW 226 3 OHM 0 1 1 4W R FXD WW 189 0 0 1 1 4W R FXD WW 190 2 OHM 0 1 1 4W R F
32. 101 and T102 pri maries Although this change of 10 kc power has equal effect on both the rfand metering bridges it is initiated by the rf bridge circuit alone The metering bridge cannot control 10 kc bias power but the 10 kc bias power does affect the metering circuit Once a change in the 10 bias power has affected unbalanced the metering bridge a separate closed dc feedback loop metering loop re establishes equilibrium in the metering circuit 4 15 Variations in 10 bias level initiated in the rf bridge circuit cause proportional unbalance of the metering bridge and there is a change the 10 kc error Signal 510 applied to the 10 kc tuned ampli fiers in the metering loop These error signal vari ations are amplified by three 10 kc amplifiers and rectified by the synchronous detector From the synchronous detector the dc equivalent 130 of the 10 ke signal is returned to the metering bridge and is monitored by the metering circuit to be indicated by the meter This dc feedback to the metering bridge acts to return bridge to its normal near balance condition IO KC METERING BRIDGE FROM RF BRIDGE BIAS IOKC ERROR SIGNAL Sioxc RECTIFIED ORC TUNED OKC SYNCHRONOUS AMPLIFIERS DETECTOR 0101 102 4103 DC BIAS CIRCUIT 0107 gt AMPLIFIER 004 105 5 5 78 Figure 4 3 Metering Bridge Circuit Mode1 431B FROM RF BRIDGE 1OKC BIAS A
33. 1121 GB 3911 1 DEPC OHM 1 1 2 19701 DC 1 OBD 1 DEPC 3K OHM 1 1 27 119701 DC 1 26 080 2 DEPC 3920 OHM 1 1 288 119701 DC 1 26 080 1 DEPC 12K OHM 1 29 1 24 19701 DC 1 2 080 1 DEPC 38 05K OHM 1 24 1 2W i 19701 DC 1 2A 08D 1 DEPC 65 18 OMM 1 24 1 2 19701 DC 1 2 1 DEPC 316 OHM 1 2 1 2W 19701 DC 1 2 080 1 DEPC 1 194X OHM 1 2 1 2W 19701 DC 1 2 1 DEPC 2 13K OHM 1 2 1 28 19701 DC 1 2A OBD 1 OEPC 3 79K OHM 1 2 1 2W 19701 DC 1 2 08D 1 DEPC 6 73K OHM 1 2 1 24 19901 DC 1 2 080 1 DEPC 21 56 OHM 1 2 1 2W 119701 DC 1 2A 1 DEPC 41 46 OHM 1 2 1 2W 19701 DC 1 2A 080 1 DEPC 46 67K OHM 1 2 1 20 19701 DC 1 24 080 1 DEPC 52 3K OHM 1 29 1 2 19701 DC 1 2 080 1 DEPC 52 55K OHM 1 2 1 2W 19701 DC 1 2 080 1 DEPC 57 46K OHM 1 2 1 2W 19701 0 1 2 080 1 DEPC 69 49K OHM 1 2 1 2W 119701 DC 1 2 OBD 1 DEPC 82 09K OHM 1 24 1 2W 119701 DC 1 2A 080 1 DEPC 94 2K OHM 1 2 1 2W 19701 OC 1 2 080 1 DEPC 142K OHM 1 2 1 24 19701 1 2 080 1 DEPC 256 8 OHM 1 2 1 28 19701 1 2 080 1 518 1 OHM 1 2W 28480 0727 0483 1 OEPC 520 1 OHM 1 1 2W 28480 0727 0484 1 DEPC 323 4 OHM 1 1 2W eos 0727 0485 1 DEPC 529 8 OHM 1 1 2 28480 0727 0486 1 FLM 1K OHM 5 1 2w 07115 20 OBD 4 MET FLM 4 7K OHM 5 0 5 107115 20 080 1 MET FLM 10K OHM 07115 20 OBD 1 MET FLM 22K OHM 5 1 2 07115 C 20 OBD 1 MET FLM 51K O
34. 318 10 320 11 323 40 32987 eos Rios 190 2 192 70 j PAGE IOF 2 P O tel Figure 5 3 Power Meter Assembly 5 12 01370 2 Model 431B 01370 3 m ee ee _ rd w o A 1 du e Lo P O AIOI JOKC OSCILLATOR AMPLIFIER 1 5 2 y EMITTER DRIVER RI55 FOL NEM 291304 51 2N383 2N388A 10 0V C123 K 47UF E AMPLIFIER 20 0108 Qui 5 0V ci24 AL ciel 3000 4 ATUF prec AMPLIFIER RUZ 9 7500 8126 1500 RI28 3300 1 1 l 2ND IOKC IO AMPLIFIER i 02 L 281304 IST ob 2 5 AMPLIFIER as 12 1000 fio Cus 281370 UE Biss JUF 42 RIS 2700 18V QUO 5 C125 I 20UF w x I w e n nm i 4 t t t 4 t 1 q 4 1 RISO 194 lo RI6 2130 3790 Ri63 6730 RI64 i2K RI65 1 21 36K
35. 4 4 4 31 DC Calibration Substitution 4 4 4 33 Regulated Power Supply 4 4 4 36 Power Switch 4 5 V MAINTENANCE 5 1 6 1 Introduction 5 1 5 4 Cover Removal Replacement 5 1 5 6 Top Cover Removal 5 1 5 7 Top Cover Replacement 5 1 5 8 Bottom Cover Removal 5 2 5 9 Bottom Cover Replacement 5 2 5 10 Side Cover Removal 5 3 9 12 Test Equipment 5 3 5 14 Troubleshooting 5 3 5 17 The Power Supply 5 3 5 21 10 Oscillator Amplifier Check 5 4 5 2 10 KC Amplifier Check 4 5 7 5 32 Metering and Feedback Circuit 5 7 9 34 Squaring Circuit Checks 5 7 5 40 Battery and Charging Checks 5 7 5 42 Battery Check 5 7 5 45 Charging Checks 5 8 9 50 Battery Warranty 5 8 5 52 Repair 5 8 5 54 Mechanical Adjustment ol Meter Zero La 5 8 5 56 Adjustments 5 9 5 57 Power Supply Adjustments 5 9 5 58 Oscillator Frequency D 9 5 63 Coarse Null Adjustment 5 9 5 69 Zero and Vernier Control Adjustment s s s 9 10 5 70 Full Scale Accuracy Adjustment 5 10 5 71 Performance Check 5 10 5 74 zero Carry Over Check 5 10 5 75 Calibration and epee ee Accuracy 5 11 VI REPLACEABLE PARTS 6 1 6 1 Introduction 6 1 6 4 Ordering Information 6 1 APPENDIX MANUAL CHANGES 11 1 1 013 10 3 Model 4918 List of Illustrations and Tables LIST OF ILLUSTRATIONS Number Title Page Number Title Page 1 1 Model 431B Power Meter
36. 4721 0687 5611 0687 5651 0690 1221 0690 3911 0727 0100 0727 0124 0727 0151 0727 0541 0727 0542 0727 0546 0727 0395 0727 0396 0727 0597 0727 0598 0727 0299 0727 0405 0727 0404 0727 0405 0727 0406 0727 0407 0727 0408 0727 0409 0727 0410 0727 0485 0727 0484 0727 0485 0758 0021 0811 0051 0811 0065 0811 0064 0811 0065 01370 3 R FXD R F XD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD RsFXO R FXD R FXO R FXD R FXD R FXO R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R FXD R F XD R FXD R FXD R FXD R FXO R FXO R FXD R FXD Section VI Table 6 2 Table 6 2 Replaceable Parts Cont d Description Mfr Mfr Part No TQ COMP 1 2K OHM 10 1 2W 01121 1221 1 COMP 150 OHM 10 1 2W 01121 EB 1511 1 COMP 1 5K OHM 10 1 2W 01121 1521 1 COMP 15K OHM 10 1 2W 01121 EB 1521 1 COMP 1 8K OHM 10 1 2W 01121 1821 1 270 OHM 10 1 2 EB 2711 1 COMP 320 OHM 10 1 2 01121 EB 5511 1 COMP 5 5 OHM 10 1 2W 01121 E8 5521 5 COMP 33K OHM 10 1 24 01121 EB 5551 1 COMP 39K OMM 10 1 2 101121 EB 3931 1 COMP 4 7 OHM 10 1 2W 101121 EB 4721 2 COMP 560 OHM 10 1 2W 01121 EB 5611 4 COMP 56K OHM 10 1 2W 01121 EB 5631 2 COMP 1 2K OHM 10 1W i 01121 98 1221 1 COMP 390 OHM 10 1W 0
37. 5 40 BATTERY AND CHARGING CHECKS 5 41 The information and procedures which follow pertain to power meters having the optional nickel cadmium battery The battery is an assembly of 20 individual permanently sealed cells connected in series At full charge battery terminal voltage should be 27 volts 1 volt Aninoperative cell reduces terminal voltage by approximately 1 3 volts 5 42 BATTERY CHECK 5 43 BATTERY VOLTAGE A dc voltmeter is needed for this test See table 5 1 for voltmeter requirements a Make sure that the Model 431B is disconnected from the ac line Connect the dc voltmeter between the BATTERY and BATTERY terminals on the etched circuit board b Set the POWER switch to BATTERY ON and observe the voltmeter reading Battery voltage should be 24 to 27 volts Ifitis not and the battery has been charged check the charging circuits and the current drain imposed by the Model 431B circuitry If the state of charge of the battery is uncertain allow a 48 hour recharge then recheck the battery voltage Check the charging circuits if the battery voltage is still not within 27 1 volt 5 17 Section V Paragraphs 5 44 to 5 55 5 44 BATTERY CURRENT DRAIN The current supplied by the battery to the Model 431B circuitry Should be checked if the battery does not seem to maintain a charge A clip on or series connected current meter see table 5 1 is required for the following procedure a Check that the Model
38. 6197 86529 86685 87216 8 413 87564 57936 88130 3822C 95421 38698 89231 89473 29665 90179 92973 91267 9 345 91418 91506 91637 91662 91737 91827 91923 91961 92189 2367 92195 92607 93332 TABLE 6 3 Manufacturer Address Festus Great Meza NY San Francesc Cal Qga a Nes Bizum Ind Berio 8 San Fsanc sco Cali San Francisco Cas Haden Carn Chicago HI Loyd Scruggs Co Electran cs Inc A J Glesenes Co Inc TRW Cagaciter Dev Satkes Inc Boonlon Me ding Company A B Beye Cc R M Bracamonte X Co Koiled Kags Inc Sean less Redbe Co CHfton Precis cn Products Co Inc Heights Pa Precision Rubber Preducts Coie Dayton Ore Radio of America Electronic Corp Devices Harrisc N J Phiicy Corgatat oe Lansdale D vesen Lansdale Pa Western Fibrous Glass Producis San Fraociscc Calil Van Waters E Rogers inc San Francisco Coif Tower Mig Coro Providence R I Cutier Hammes tne Lincoln IH Gould Nalsonat Batteries Inc St Paul Minn Telephone amp Radi Corp Chiffon N J General Mills Inc Buffale N Y Graybar Electric Co Oakland Call Genera Electric Distributing Corp Schenectady United Transto mer Co Chicago 144 US Rubber Co Consumer lod amp Plastics Div Passaic N Bearing Engineering Co San Francisco Canl Connor Spring Mfg San
39. 687 1551 R FXD COMP 15K OHM 10 1 2W R140 0686 1025 R FXD COMP 1K OHM 5 1 2W R141 0687 5951 R FXD 39K OHM 10 1 2 R142 0687 1221 R FXO COMP 1 2K OHM 10 1 2W R143 0687 5611 R FXD COMP 560 OHM 10 1 2W RI44 0687 5611 R FXD COMP 560 OMM 10 1 2W 8145 THRU R149 NOT ASSIGNED R150 0727 0151 R FXD 5920 OHM 1 1 2W R151 0687 5221 R FXD COMP 3 3K OHM 10 1 2W R152 0727 0124 R FXD DEPC 3K OHM 1 1 2W R153 0727 0124 R FXD DEPC 3K OHM 1 1 2W R154 0687 5611 R FXD COMP 560 OHM 10 1 24 R155 0687 5511 RsFXO COMP 330 OHM 10 1 28 R156 THRU R159 NOT ASSIGNED R160 0727 0596 R FXD DEPC 1 198 OHM 1 2 1 2W R161 0727 0397 R FXD DEPC 2 12 OMM 1 29 1 2W R162 0727 0598 R FXD DEPC 3 79K OHM 1 2 1 2W R163 0727 0399 R FXD DEPC 6 73K OHM 1 2 1 24 R164 0727 0341 R FXD DEPC 12K OHM 1 2 1 2W R165 0727 0400 R FXD DEPC 21 36K OHM 1 2 1 2 R166 0727 0342 R FXD DEPC 28 05K OHM 1 24 1 2W R167 0727 0407 R FXD DEPC 82 09 OHM 1 2 1 24 R165 0727 0346 R FXD DEPC 63 14K OHM 1 2 1 2W R169 0727 0408 R FXD DEPC 52 55K OHM 1 2 1 2W R170 0727 0402 R FXD DEPC 46 67K OHM 1 2 1 2W R171 0727 0401 R FXD DEPC 41 46K OHM 1 2 1 2W R172 0727 0403 R FXD DEPC 52 3K OHM 1 29 1 gW R173 0727 0405 R FXD DEPC 57 46K OHM 1 2 1 2W R174 0727 0406 R FXD DEPC 69 49K OHM 1 2 1 54 R175 0727 0408 R FXD DEPC 94 2K OHM 1 28 1 2W R176 0727 0409 R FXD DEPC 142K OHM 1 28 1 2W R177 0727 0410 R FXD DEPC 256 8 OHM 1 24 1 2W R178 0
40. 687 5631 R FXO COMP 56K OHM 10 1 2W R179 0687 5631 R FXD COMP 56K OHM 10 1 2W R180 0758 0021 R FXD MET FLM 51K OHM 5 1 2W R181 0727 0100 R FXD OEPC 1K OHM 1 1 2W 51 3101 0033 SWITCH SLIDE LINE VOLTAGE sz 3100 0370 SWITCH ROTARY POWER 55 THRU 5100 NOT ASSIGNED 101 3101 0032 SWITCH SLIDE MOUNT RES 5102 2100 0273 SWITCH sROTARY RANGE See list of abbreviations in introduction to this section 01370 3 6 5 Section VI Table 6 1 Reference Designation 6 6 Model 431B Table 6 1 Reference Designation Index Cont d 4p Stock No Description No 9100 0141 9120 0066 9120 0066 9120 0065 9120 0065 8120 0078 1400 0084 431B 60A 0570 0064 0570 0067 0270 0104 5000 0705 5060 0718 2000 0717 5060 0728 431B 16A 8218 19 4518 198 451B 10W 0510 0122 1205 0002 9211 0160 9220 0225 TRANSF ORMER POWER NOT ASSIGNED TRANSF ORMER AUDIO TRANSFORMER AUDIO TRANSF ORMER AUDIO TRANSFORMER AUDIO ASSY POWER CABLE SMOOTH BLACK EXTRA LIMP 7 5 FT NEMA PLUG IN FUSEHOLDER EXTRACTOR POST ASSY COIL INCLUDES L1 RB MISCELLANEOUS KNOB VERN IER KNOB ZERO KNOB sPOWER RANGE COVER 6 X ll COVER HALF RECESS COVER HALF MODULE BOTTOM FOOT ASSY HALF MODULE ASSY CABLE 5 THERMISTOR MOUNT ASSY POWER SWITCH INCLUDES Rl S2 ASSY MOUNT RES SWITCH INCLUDES R101 S101 ASSY RANGE SWITCH INCLUDES 8117 THRU R124 102 R160 THRU R166 STK 4318
41. 8 79915 76005 76210 16433 76487 76433 76530 75545 76854 11066 11015 71221 77252 77342 77630 77638 11164 11969 18189 78283 78280 78452 78411 78488 78493 78553 78790 28947 73136 79342 79251 7972 79963 8003 40120 80130 8013 80207 80223 80748 89294 80411 80486 80509 Manvfocturer Address Hugh H Eby Inc Gudeman Co Rober M Hadley Co Philadelphia Pa Chicago 111 Los Angeles Techaologicat Products Inc Pa Hansen Nig Co Inc Princeton Ind B M Harper Co Chicago Helipot Div of Beckman inst inc Fullerton Calit Hughes Products Division Hughes Artcraft Co Newport Beach Call Electronic Co Div of North American Phillips Co Inc Hicksville N Y Bradley Semiconductor Corp Hamden Conn Carling Electric inc Hanford Coon George K Garreti Ca Duy MSL Industries Inc Federal Screw Products inc Fischer Special Co The General Industries Co Goshen Stamping 8 Tool Co JFD Electronics Corp Jennings Radio Mig Corp Signatite Inc Philadelphia Pa Chicago 111 Concianali Ohio Goshen Ind Brooklyn San Jose Cal Neptune N J J H Winns and Sons Winchester Mass Industrial Condenser Corp Chicago III ALF Products Division of Amphenol Borg Electromes Corp Danbury Conn Johnson Co Waseca Minn International Resistance Co Philadelp
42. 8135 1N941 D2361 313 150 215564 K5 8D 0 6613M SPECIAL 46 5000 0703 2000 6717 5060 0718 Model 431B PPHPP PPPpP _PPPPH PNPP 01370 3 Model 4518 Code No Menufacturet Address 50 20 U S A Common Any supplier U S 05136 McCoy Electiomcs Mount Holty Springs Pa 552213 Sage Electronics Corp Rochester N Y 36334 Murridial Cotton Cal 20373 Garioch Inc Electonics Products On Camden 00656 Aerowos Corp New Bedtord Mass 39719 dec Harrisburg Pa 09781 Auctolt Radio Corp Boonlon R J 05815 Norinerr Engineering Laborioci s Inc Burlington Wis 00852 Sangame Elecnic Co Picxens Dor Pickens S C 00866 Engineering Co Los Angeles Calif 00891 Holmes Corp Los Angeles Calif 01121 Area Bradley Milwaukee Wis 651255 Litlon Industries Inc Beverly Hills Call 0126 Semiconductoss Inc Lawndale Calif 01295 Texas Jasisuments Inc Transistor Products Div Dallas Texas 01349 The All ance Mfg Co Ailiance Omo 01589 Pacific Relays Inc Van Nuys Call 01930 Amecgek Corp Rocktora WI 0196 Pulse Engineering Co Santa Clara Calif 02114 Ferroacube Corp of America Saugerbes X Y 02286 Cole Rubber and Plastics Inc Palo Alto Catit 02660 Ampheno Borg Eleclronics Corp Chicago 02735 Radio Carp af America Semiconductor and Malesials Dov Somerville R J 02771 Vocaline of America in
43. A 57 1200 1 1 Ferte 1 I 4 NOTES 28 LI S oJ CHARGE I UPPER AND LOWER BE il tied ea ae VOLTAGE LIMITS GIVEN i REFERENCE DESIGNATORS VARIOUS POINTS THRU CIRCUIT PI THERMISTOR MOUNT IS I 01 5 CONNECTED 4318 I FOR THESE MEASUREMENTS 1 Ri 7 9 19 i 5 2 2 Jz CIRCUIT BOARD COMMON A RAI CE m CHASSIS GROUND FRONT PANEL C ENGRAVING REAR PANEL L ENGRAVING COPYRIGHT 1962 BY HEWLETT PACKARD COMPANY 5 SCREWDRIVER ADJUSTMENT 1 8 SWP S po v 22 8CDEF 8 ROTARY SWITCH 7 amp TEST POINT Figure 5 4 Power Supply TIPO Model 4318 Section VI Paragraphs 6 1 to 6 7 SECTION VI REPLACEABLE PARTS 6 1 INTRODUCTION 6 2 This section contains information for ordering replacement parts Table 6 1 lists parts in alpha numerical order of their reference designators and indicates the description and stock number of each part together with any applicable notes Table 6 2 lists parts in alpha numerical order of their stock numbers and provides the following information on each part a Description of the part see list of abbreviations below b Typical manufacturer of the part in a five digit code see list of manufacturers in appendix c Manufacturer s stock number d Total quantity used in the instrum
44. DO NOT CHANGE THE SETTING OF THE LINE VOLTAGE SWITCH WHEN THE POWER METER IS OPERATING 2 15 INITIAL BATTERY OPERATION CHECK 2 16 The following applies to option 01 instruments or instruments that have field installed batteries When the battery is used as the Model 431B power source for the first time perform the following steps a Connect Model 431B to ac source Set POWER switch to CHARGE and charge battery for a minimum of 16 hours or overnight Note the battery can be maintained in the charging state indefinitely without damaging the battery It will assume its full capacity 1 25 ampere hour and no more b Perform turn on procedure given in figure 3 2 with POWER at AC If the procedure checks out normally proceed to step c O ADAPTER FRAME INSTRUMENT We SPACER CLAMP RETAINING SCREWS Figure 2 4 Two Half Modules in Rack Adapter 01370 3 Section II Paragraphs 2 14 to 2 18 c Repeat turn on procedure given in figure 3 2 with POWER at BATTERY ON If operationis not the same as that obtained with ac power applied refer to paragr 5 40 Battery and Charging Checks 2 17 REPACKAGING FOR SHIPMENT 2 18 The Model 431B is shipped in a foam pack and cardboard carton see figure 2 5 When repackaging the instrument for shipment the original foam pack and cardboard carton can be used if available If not available they can be purchased from Hewlett Packard Co refer to section VI misc
45. E 200 THERMISTOR MOUNT PER CABLE 200 THERMISTOR MOUNT 478A POWER SWITCH INCL 1 52 4518 16 MOUNT RES SWITCHCINCL R101 5101 RAND SWITCH INCL R117 THRU R166 ETCHED CIRCUIT RECHARGEABLE BATTERY INSTALLATION KIT RETAINER INDIGATOR LIGHT R FXD COMP 1K OHM 5 1 4W R FXD COMP 220 OHM 5 1 4W R FXD COMP 24K OHM 5 1 4W COMP 2 7K OHM 5X 1 AW R FXD COMP 33 OHM 5 1 4 R FXD COMP 430 OHM 5 1 AW R FXD COMP 75 OHM 5 1 R FXD COMP 910 OHM 5 1 4W R FXD COMP 1K OHM 5 R FXD COMP 1 5K OHM 5 1 2W R FXD COMP 15K OHM 5 1 2W R FXD COMP 2 7K OHM 5 1 2W R FXD COMP 3 3K OHM 5 1 2W R FXD COMP 7 5K OHM 5 1 24 See list of abbreviations in introduction to this section 0121 0035 OMI 56 470 DM15F 201F 500 H 1038 5G11A CD20F 212F 114P1042R5S3 300198A1 300182A1 597541 1500606 000682 41D 0340 0086 0340 0090 0370 0064 0370 0069 0370 0104 4314 16A 431A 166 451 6 431A 64A 421 648 4218 16 4318 16C HHHIOHP P 4318 160 L 2215 16 4518 16E 431B 16F 4318 16F 4318 16G 4318 16G 851 19 451 198 4518 19W 4518 65 4518 95 PH C12008 014 4 CB 1025 CB 2915 CB 2435 2725 CB 3305 Eeee OPTIONAL 01370 3 Model 4918 Stock 0687 1221 0687 1511 0687 1521 0687 1521 0687 1821 0687 2711 0687 5511 0687 5521 0687 5551 0687 3931 0687
46. EMENT a Rest the cover flat on the cast guides projecting inward near the top of each side frame see I figure 5 1 b Slide the cover forward allowing its forward edge to enter the groove in the front c Replace the two cover retaining screws Test Equipment Range 0 5 to 50 volts dc Accuracy 0 2 Resolution three digit Ohmmeter Continuity amp resistance Range 1 ohm to 10 megohms checks Accuracy 5 of full scale Milliammeter Calibrator EE MEME 3 to 60 ma dc A 5 Oscilloscope AC voltmeter Instrument Recommended fp 405BR CR 410B 412A Sensitive Research Instrument Corp Model B Bamilek Accuracy 0 1 of full scale Range Oto 30 ma 8402 Power Meter Calibrator Current accuracy 0 1 Resistance accuracy 0 2 tp 412A 9 428 Bandwidth 100 ke Accuracy 5 Input impedance 1 megohm Sensitivity 130B C d 120B 122A 1 mv em Accuracy 5 Input impedance 1 megohm Range 01 to 100 mv 400D H L 403A B 5 1 Section V Paragraphs 5 8 to 5 9 431B Table 5 1 Test Equipment Cont d Instrument L EN instrument tical 5 ficat DC Source or Power Meter Calibrator Calibration accuracy check Range 0 to 220 vdc or Current Output 0 to 20 ma tp 711A 712B Power Supplies 8402A Power Meter Calibrator Thermis
47. HM 5 1 2W 07115 20 08D 1 WW 200 3 OHM 0 1 1 4W 05347 LR 205RP 080 2 WW 189 OHM 0 5 1 4W 05347 LR 205RP 080 1 ww 255 OHM 0 5 1 4W 05347 LR 205RP OBD 1 WW 511 OHM 1 0 08W 99957 M3 A 080 2 4 See list of abbreviations in introduction to this section 6 9 Section VI Table 6 2 Table 6 2 fp Stock No Description 0811 0066 R FXD ww 887 OHM 1 0 08W 0811 0085 R FXD W 201 5 OHM 0 1 1 4W 0811 0086 R FXO WW 203 3 OHM 0 1 1 4W 0811 0087 R FXD Ww 207 1 OMM 0 1 1 38 0811 0088 R FXD ww 206 6 OHM 0 1 1 4W 0811 0089 R FXD WW 213 0 OHM 0 1 1 4W 0811 0090 R FXD WW 226 3 OHM 0 1 1 4W i 0811 0091 R FXO WW 256 0 OHM 0 1 1 4W i 0811 0092 R FXD WW 261 4 OHM 0 1 1 4W 0811 0093 R FXD WW 268 2 OHM 0 1 1 4W 0811 0098 R FXD WW 190 2 OHM 0 1 1 44 0811 0095 R FXD ww 192 7 OHM 0 1 1 4W 0811 0096 R FXD WW 200 7 OHM 0 1 1 4W 0811 0098 R FXD ww 258 0 OHM 0 1 1 4 0811 0099 R FXD ww 202 5 OHM 0 1 1 4W i 0811 0101 R FXD ww 208 2 OHM 0 1 1 4W 0811 0112 R FXD WW 197 7 OHM 0 1 1 4W 1120 0511 ME TER sCAL SRATEO i 1205 0002 HEAT SINK TRANSISTOR 1251 0066 JACK TELEPHONE FOR 2 CONNECTOR PLUG 1251 0148 CONNECTOR sPOWER MALE 3 PIN 1251 0149 CONNECTOR FEMALE 6 CONTACT 1400 0084 FUSEHOLDER EXTRACTOR POST TYPE 1420 0009 BATTERY RECHARGEABLE 1 25 AH 1450 0048 LAMP NEON 1850 0040 TRANSISTOR GERMANIUM 2N383 1850 0064 TRANSISTOR GERMANIUM 2 1185 1850 0065 TRANSIS
48. L101 THRU L105 R150 THRU R155 THRU 05 R167 THRU R178 0101 THRU 0111 R180 R2 THRU R Z1 RQ THRU R14 SEE 01 0180 0049 ELECT 20 UF 50VDCW C2 0180 0138 C FXD ELECT 100 UF 100 10 40VDCW C3 0150 0012 C FXD CER 0 01 UF 20 1000VDCW 0160 0174 C FXD CER 0 47 UF 80 20 25VDCW 5 0180 0059 C FXD ELECT 10 UF 100 10 25VDCW C6 0180 0105 C FXD ELECT 50 UF 25VDCW C7 THRU C100 NOT ASSIGNED C101 0140 0220 C FXD MICA 200 1 300VDCW C102 0160 0185 C FXD MICA 2100 PF 1 300VDCW C103 0121 0035 C VAR AIR 7 2 145 2 PF C104 0140 0204 C FXD MICA 47 PF 5 SOOVDCW 105 0140 0220 C FXD MICA 200 PF 1 300VDCW C106 0180 0106 C FXD ELECT 60 UF 6VDCW C107 THRU C109 NOT ASSIGNED 110 0160 0174 CER 0 47 UF 480 205 25VDCW C111 0180 0059 C FXD ELECT 10 UF 100 10 25VDCW C112 0170 0069 C FXD POLY 0 1 UF 2 50VDCW C113 0160 0174 C FXD CER 0 47 UF 80 20 25VDCW C114 0180 0059 C FXD ELECT 10 UF 100 10 25VDCW 0115 0170 0069 C FXD POLY 0 1 UF 2 SOVDCW C116 0180 0059 C FXD ELECT 10 UF 100 10 25VDCW C117 0160 0174 C FXD CER 0 47 UF 80 20 25VDCW C118 0180 0105 C FXD ELECT 50 UF 25VDCW C119 0180 0105 C FXD ELECT 50 UF 25VDCW C120 0160 0174 CER 0 47 UF 80 20 25VDCW C121 0180 0059 C FXD ELECT 10 UF 100 10 25VDCW C122 0180 0059 C FXD ELECT 10 UF 100 10 25VDCW C123 0160 0124 C FXD CER 0 47 UF 80 20 25VDCW C124 0170 0069 C FXD POLY 0 1 UF 2 50VDCW C125
49. ND COMPENSATION THERMISTOR AMPLIFIER 0101 102 T103 MIOI RI38 CRIO5 Figure 4 4 Nulling Circuit 4 16 The reactive components of the metering bridge are balanced with variable capacitor C103 and inductor L102 Null adjust C103 is an operational adjustment and L102 is a maintenance adjustment Null adjust C103 is adjusted with the RANGE switch inthe NULL position A simplified schematic diagram ofthe NULL circuit is shown in figure 4 4 The 10 kc signal is taken at the synchronous detector rectified by CR105 and read on the meter The rectified signal contains both reactive and resistive voltage components of the bridge unbalance 4 17 SYNCHRONOUS DETECTOR 4 18 The synchronous detector converts the 10 kc error signal from the metering bridge to a varying dc signal simplified schematic of the synchronous detector is shown in figure 4 5 The detector isa bridge rectifier which has a rectifier in series with a linearizing resistance in each of its arms Two 10 kc voltages designated and E4 in figure 4 5 are applied to the bridge 1 voltage induced in the secondary of transformer 103 is proportional to the metering bridge error signal and is incoming from 10 kc tuned amplifier Q103 2 voltage E4 induced in the secondary of T104 is proportional to a voltage supplied by the 10 kc oscillator amplifier Voltage E4 is much larger than voltage E3and switches appro priate diodes in
50. OPERATING AND SERVICE MANUAL MODEL 431B POWERMETER SERIALS PREFIXED 451 FOR OTHER SERIALS SEE APPENDIX Copyright HEWLETT PACKARD COMPANY 1962 1501 PAGE MILL ROAD PALO ALTO CALIFORNIA U S A 2 1370 3 Printed SEP 1955 Table of Contents TABLE OF CONTENTS Section I GENERAL INFORMATION 1 1 Description 1 6 Accessories E 1 8 Instruments with Options 1 10 Instrument Identification H INSTALLATION 2 1 Inspection 2 3 Installation 2 5 Rack Mounting 2 9 Three Conductor Power Cable 2 12 Primary Power Requirements 2 15 Initial Battery Operation Check 2 17 Repackaging for Shipment OPERATION 3 1 Introduction 3 3 Mechanical Adjustment of Meter Zero 3 5 Controls and indicatore 3 7 Operating Instructions 3 9 Battery Operation 3 11 Battery Charging Pies 3 13 Battery Charge Check 3 15 Major Sources of Error Microwave Power Measurements Power Meter Accuracy of 1 Greater Using the DC Substitution Method Equipment Used for DC Substitution Additional Applications EORY OF OPERATION Overall Description Circuit Description RF Bridge Circuit Metering Bridge Circuit Synchronous Detector Differential Amplifier Q104 Q105 Feedback Current Generator Q107 lt 4 SUE ae io a pa gt 9 D I t NI Ea DI DI NIN Model 4518 Section Page 4 25 Meter Circuit
51. Pla view N Y 05783 Stewart Engineering Co Santa Ciu2 Call 05820 Wakefield Engineering Inc Wakefield Mass 06094 The Bassich Co Bndgepori Conn 06175 Bausch and Lomb Optical Rochester N Y 06402 E TA Products Co of America Chicago III 06475 Westein Devices inc Burbank Cait 06540 Amaiom lecttonic Hardware Co inc New Rochelie N Y 06555 Beede Ejectitcal Instrument Co Inc Penacook N H 08586 General Devices Ca Inc Indianapolis Ind 0675 Corp of America U S Semcos Div Phoenix Anz 06812 Mtg Co West Div Van Nuys Cali 06980 Etet McCullough Inc San Carlos 07088 Kelvin Electric Co Van Ruys Cali 01115 Comming Glass Wok Electronic Companenis Dept Bradford a 07126 Digittan Co Pasadena Calif 00015 4 6 3 CODE LIST MANUFACTURERS Section Table 6 3 The following code numbers are from the Federal Supply Code for Manufacturers Cataloging Handbooks H4 1 Name to Cade 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 Revised 1365 01370 3 Code No 97137 07138 97149 07233 07261 07253 07322 07387 07700 07910 07933 07966 07980 08 45 08289 08358 08664 08717 08718 08792 98384 09026 09134 9145
52. TOR GERMANIUM 2N1370 1851 0017 TRANSISTOR GERMANIUM 2N1304 1851 0024 TRANSISTOR GERMANI UM 2N388A 1854 0003 TRANSISTOR SILICON 18 TRANSISTOR SILICON 1901 0024 DIGDE SILICON 1901 0025 DIODE SILICON 50 1V 100 PIV 1902 0017 DIODE SILICON AVALANCHE 1902 0018 DIODE SILICOM AVALANCHE 1910 0016 DIODE GERMANIUM 100 MA 1 60 PIV 2100 0182 R VAR COMP 5 5 OHM 10 LIN 1 50 2100 0542 R VAR WW 2SECT 10K 800 OHM 10 2W 2110 0017 FUSE CARTRIDGE 0 15 5100 0275 SWITCH ROTARY RANGE 3100 0370 SWITCH sROTARY POWER 5101 0052 SWITCH SLIDE MOUNT RES 3101 0033 SWITCH SLIDE LINE VOLTAGE 5000 0703 COVER 6 X 11 5000 0717 COVER HALF MODULE BOTTOM 5060 0652 BINDING POST BLACK 5060 0633 BINDING POST RED 5060 0718 COVER HALF RECESS TOP 5060 0728 FOOT ASSY HALF MODULE 8120 0078 9100 0141 9110 0040 9120 0065 9120 0066 9140 0122 ASSY POWER CABLE BLACK TRANSFORMER POWER INDUCTOR AUD I 0 TRANSFORMER AUDIO TRANSFORMER AUDIO COIL VAR 2 WINDINGS 9 20 UH EACH See list of abbreviations in introduction to this section Replaceable Parts Cont d Mtr Mfr Part No M3 A OBD 0811 0085 0811 0086 0811 0087 0811 0088 0811 0089 0811 0090 0811 0091 0811 0092 0811 0095 0811 0094 0811 0101 0811 0112 1120 0311 3AL635 2R 24 1359 106 16 51 Al PC6F 1000 542015 OBD 858 R 28585 281185 281370 2 1504 2N388A 5 5056 RT 2022 G 552 1 0502692 PS
53. Use the following as a general guide for repackaging the instrument a Place the instrument in the foam pack as shown in figure 2 5 b Mark the packing box with Fragile Delicate Instrument Note If the instrument is to be shipped to Hewlett Packard for service or repair attach to the instrument a tag identifying the owner and indicating the service or repair tobeaccom plished include the model number and full serial number of the instrument In any correspondence identify the instrument by model number serial number and serial number prefix di INSTRUMENT ___ FOAM PACK lt 7 __ CARTON gt w 620 Figure 2 5 Repackaging for Shipment 2 3 2 4 Model 4518 Section Paragraphs 3 1 to 3 16 SECTION Ill OPERATION 3 1 INTRODUCTION 3 2 The Model 431B Power Meter measures power ranging from 01 to 10 milliwatts with power meter accuracy of 3 zero carries over from range to range within 0 5 of fullscale whenthe me ter is zeroed on the most sensitive scale 3 3 MECHANICAL ADJUSTMENT OF METER ZERO 3 4 The procedure for performing the mechanical adjustment of the meter zero is given in section V paragraph 5 54 3 5 CONTROLS AND INDICATORS 3 6 The front and rear panel controls and connectors are explained in figure 3 1 The explanations are keyed to corresponding controls and indicator on the drawing of the fro
54. VING CURRENT 4 30 ZEROING Perfect balance of the metering bridge would mean that no 10 ke error signal would be applied to the 10 kc amplifiers there would be no dc feedback from Q107 and the metering loop would be open With an open metering loop zero reference could not be accurately established In the Model 4 4 Model 431B TO METERING BRIOGE OKC BIAS _ BRIDGE DETECTION HERMISTOR Ry DC CALIBRATION L LA SUBSTITUTION J102 I IO KC ERROR SIGNAL 50 5 176 Figure 4 9 DC Calibration and Substitution 431B this occurrence is prevented by insuring a closed metering loop even when the ZERO control causes the meter pointer to deflect downscale from zero By the combined actions of R141 and R179 the zero setting of the meter pointer does not coincide with absolute balance of the metering bridge A slight unbalance of the bridge is maintained by R141 while R179 provides a counter action in the feedback current squared generator Q106 so that the meter can indicate zero even though the metering bridge is not perfectly balanced Resistor R179 also sets the full scale accuracy of the meter 4 31 DC CALIBRATION AND SUBSTITUTION 4 32 A simplified schematic diagram of the dc cali bration and substitution circuit is shown in figure 4 9 Highly accurate rf power measurements be made using the dc substitution technique given in figure 3 3 In the
55. Wire Cloth Products Inc Bellwood Ill Worcesle Pressed Aluminum Corp Worcester Mass George Philbi cs Researchers Inc Boston Mass Miami Fla Woodside Long Island N Y Burbank Cali Sheridao Wyo Bridgeport Conn Bloomfield N J Chicago Franklin Ind Chicago Sunnyvale Cal Eas Paterson N J Chester Pa Alles Products Contenentat Connector Corp Leecratt Mfg Co Inc terca Electronics Inc National Coll Co Vitramon Inc Gordo 8 Corp Methode Mig Co Qage Electric Co Inc Wockesser Co Huggias Lobotatoties Hi Q Div of Aetovox Corp Olean N Y Thordarson Merssnet Div Maguire Indusimes Mt Carmel 111 Sola Manutaclusing Co Carilon Screw Co Microwave Associates Inc Excel Transformer Co industrial Retasmag Ring Co Automatic Precision Mfg Reon Resistor Corp Litton System loc Adlei Mestric Commun Div New Rochelle N Y R Troncis Inc Jamaica N Y Rubber Teck Inc Gaidena Calif Francis L Moseley Pasadena Calil Microdot Inc 50 Pasadena Call Sealectio Corp Mamaroneck N Y Catad Corp Redwood City Los Angeles Calf Chicago Burlington Mass Oakland Calit Irvington N J Englewood N J Yonkers N Y Code No 95731 98821 98925 98978 99109 99313 99515 9970 99800 99832 99934 99912 9957 Model 431B Manufacturer Address Genera Mills Inc Electronics Div Minneopn
56. XD WW 192 7 OHM 0 1 1 4W R FXD Ww 197 7 OHM 0 1 1 4W R FXD WW 208 2 OHM 0 1 1 4W R FXD WW 255 0 OHM 0 1 1 4W R FXO WW 256 0 OHM 0 1 1 4W R FXD WW 258 0 OHM 0 1 1 4W R FXD WW 268 2 OHM 0 1 1 4W R FXD WW 511 OHM 1 0 06W R FXD WW 887 OHM 1 0 08 R FXO FLM 22K OHM 5 1 2W R FXD WW 511 OHM 1 0 08W R VAR CONCENTRIC FRONT SECT WW 10K OHM 10 LIN 28 REAR SECT WW 800 OHM 10 LIN 2W NOT ASSIGNED R FXD R FXD R FXD R FXD R FXD R FXO R FXD R F XD R FXD FXB R FXD R FXD R FXD R FXD COMP COMP COMP COMP 7 5 OHM 5 1 2W 3 3K OHM 5 1 2W 2 7 OHM 5 1 2W 2 2 OHM 5 1 2W COMP 430 OHM 5 1 4W COMP 33 OHM COMP 75 OHM COMP 220 OHM COMP 1K OHM 5 1 4W 24K OHM 1 4W COMP 5 910 OHM 5 1 4W A COMP COMP COMP COMP 2 7K OHM 5 1 4W 1K OHM 5 1 2W 1 5K OHM 5 1 2W See list of abbreviations in introduction to this section 01370 3 Model 431 Section Table 6 1 Table 6 1 Reference Designation Index Cont d SE SIE n Stock No Description Note R127 0686 7525 R FXD COMP 7 5 OHM 5 1 2W R128 0686 3325 R FXD COMP 3 3K OHM 1 2W R129 0686 1535 R FXD COMP 15K OHM 5 1 2 R130 0687 3521 R FXD COMP 3 3K OHM 10 1 24 R131 0687 5611 R FXD COMP 560 OHM 10 1 24 R132 0686 3325 R FXD COMP 2 2 OHM 5 1 2W R133 0687 1511 R FXD COMP 150 OHM 10 1 2W R134 THRU R137 0758 0003 R FXD MET FLM 1K OHM 5 1 2W R138 0687 1521 R FXD COMP 1 5K OHM 10 1 2W R139 0
57. a Co Spruce Pine N C Computer Diode Corp Lodi N idea Prec Meter Co Inc De Jur Meter Diy Brooklyn Deico Radio Oiv of G M Corp Kokomo Ind Thermofelics Inc Canoga Park Calif Tranex Company Mountain View Cali Ty Cat Mtg Inc Hollislon Mass Radio Industries Des Plaines Curtis Instiyment Inc Mi Kisco DuPont and Co lac Wilmington Del The Bendix Corp Ecligse Proneer Div Thomas A Edison Industries Div ot McGraw Eoison Co West Orange N J Electra Mfg Co independence Kansas Teterboro N S Elmira NY Code 20183 21226 21520 21335 24455 24655 26365 26462 26992 28480 33173 39434 36196 37942 39543 40920 42190 43990 44555 47904 48620 49956 52090 52983 54294 55026 55433 55938 6137 56289 59446 59730 60741 61775 62119 63743 64959 65092 66295 65346 70276 70309 70318 10485 20563 70993 10998 71002 71041 11218 11286 11313 11400 71436 7144 71450 71468 71471 73482 11590 11616 11700 71744 31753 11185 11384 12136 7170 72354 12619 72656 72765 Manufacturer Address Genera Atronics Corp Esecutone Inc Fansieel Metallurgical Coro The Fafnu Bearing Co G E Lamp Divisio Nela Park Cleveland Orio General Radio Co West Concord Mass Gries Reproducer Corp New Rochelle X Y Grotet File America Inc Caristadt N J Lancaster Pa Palo Alto Call Owensboro Ky
58. and out ofthe circuitto rectify voltage Section a of figure 4 5 shows the current path through diodes CR102 and CR104 for a positive going signal section b shows the current path through diodes CR101 and CR103 for a negative going signal The rectified output is taken at the center taps of trans formers T103 and T 104 4 19 Operation of the circuit is as follows When the left side of T104 is positive with respect to the right side as in figure 4 5a diodes CR102 and CR104 con duct while diodes CR101 and CR103 are biased off With the polarities reversed as in figure 4 5b the 01370 2 Model 4918 SYNCHRONOUS DETECTOR FROM IOKC TUNED AMPLIFIER 3 lt RECTIFIED OUTPUT OSCILLATOR AMPLIFIER Section IV Paragraphs 4 20 to 4 24 SYNCHRONOUS DETECTOR FROM TUNED AMPLIFIER 0105 RECTIFIED OUTPUT eo lt er i FROM OSCILLATOR AMPLIFIER Figure 4 5 Synchronous Detector diodes CR102 and CR104 are biased off The resultant output is a pulsating dc signal equivalent tothe applied 10 ke error signal This pulsating dc signal is filtered and applied to differential amplifier Q104 Q105 4 20 Proper synchronous detector output requires an in phase relationship between E3 and E4and for ampli tude of E4 to be larger than that of E3 4 21 DIFFERENTIAL AMPLIFIER Q104 Q105
59. ard motion c Use a special tool to remove components having multiple connections such as potentiometers trans formers etc Refer to table 5 1 for type of soldering tip required d Use a toothpick to free hole of solder before in stalling a new component 5 54 MECHANICAL ADJUSTMENT OF METER ZERO 9 55 When meter is properly zero set pointer rests over the zero calibration mark on the meter scale when the instrument is 1 atnormal operating temper ature 2 in its normal operating position and 3 turned off Zero set as follows to obtain best accu racy and mechanical stability a Allow the instrument to operate for at least 20 minutes this allows the meter movement to reach normal operating temperature b Turn instrument off and allow 30 seconds for all capacitors to discharge c Rotate mechanical zero adjustment screw until pointer is on zero Reverse direction of adjustment screw approximately 3 in order to free adjustment screw from meter movement If the pointer moves while freeing the adjustment screw this step must be repeated Note Use of the parallax eliminating mirror on the meter scale increases the accuracy of the mechanical zero set 01370 1 Model 4918 5 56 ADJUSTMENTS 5 57 SUPPLY ADJUSTMENT a Connect dc voltmeter see table 5 1 for quired specifications between the negative end o C6 and Model 431 ground b Adjust 18 v REG ADJ R13 for 18 vdc
60. are secure frame g The complete assembly is ready for rack mounting 2 9 THREE CONDUCTOR POWER CABLE 2 10 To protect operating personnel the National Electrical Manufacturers Association NEMA rec ommends that the instrument panel and cabinet be grounded All Hewlett Packard instruments are equipped with a three conductor power cable which when plugged into an appropriate receptacle grounds the instrument The offset pin on the power cable three prong connector is the ground wire 2 11 To preserve the protection feature when oper ating the instrument from a two contact outlet use a three prong to two prong adapter and connect the green pigtail on the adapter to ground 2 12 PRIMARY POWER REQUIREMENTS 2 19 The Model 431B can be operated from an ac or de primary power source The ac source can be either 115 or 230 volts 50 to 1000 cps de source is a 24 volt rechargeable battery The rechargeable battery is supplied with option 01 instruments only 01370 3 Model 4518 2 14 For operation from ac primary power the instrument be easily converted from 115 to 230 volt operation The LINE VOLTAGE switch Sl a two position slide switch located at the rear of the instrument selects the mode of ac operation The line voltage for which the instrument is setto operate appears on the slider of the switch A 15 100 ampere slow blow fuse is used for both 115 and 230 volt operation CAUTION
61. c Old Saybrook Conn 02777 Hopkins Engineering Co San Fernando Cali 03508 Semiconductor Prod Dept Syracuse NY 03705 Apex Machine amp Tool Co Dayton ho 0379 Elgema Comptos Cal 03877 Tiansitton Eleclric Corp Wakelield Mass 03888 Pyrolsim Resistor Co lac Cedar Xnolls 03954 Singer Co Died Doe Finderne Plant Somerville N J 04009 and Hegemao Elect Co Hartford Conn 04013 Taurus Corp Lambeilvilie 04062 Elmenco Products Co New York 04222 Ki Q Division of Aetovos Myitie Beach S C 04354 Precision Papes Tube Co Chicago Hl 04404 Dymec Division Hewlett Packard Co Palo Alto Calif 0465 Sylvania Electerc Products Mictawave Device Div Mountain View Caldi 04713 Motorola inc Semiconductor Prod Drv Phoenix Arizona 04732 Fatson Co inc Westera Div Culver City Calit 04773 Automatic Electric Co Northlake 111 04296 Sequoia Wire Co Redwood City Calif 04811 Precesian Carl Spring Co El Monte Catt 04870 P M Motor Company Westchester ili 05006 Twentieth Century Plastics Inc Los Angeles Cant 0521 Westinghouse Electiic Corp Semi Conductat Youngwaod Pa 05347 Ulironis tac San Mateo Calif 05593 linmitconic Engineering Sunnyvale Calif 05616 Cosmo Plastic 70 Electrical Spec Cleveland Ohio 05624 Barber Colman Co Rockford HI 05728 Tulen Optical Co Rosiyn Heights Long Island 05729 Mero Tel Corp
62. ces by substituting dc power for 10 power Since the 10 power equaled the applied rf power the substituted dc power is also equal to the applied rf power Instead of metering the feedback current directly which would require the use of a nonlinear meter scale an analog current is derived which is proportional to the square of the feedback Since power is a square law function of current the analog current thus derived is pro portional to rf power making possible the use ofa linear scale on the meter 4 5 There is little drift of the power meter zero point when ambient temperature at the thermistor mount changes If for example ambient temperature at the mount increases a decrease in electrical power to the thermistors is required to hold their operating resistances constant The decrease for both therm istors is made automatically by the detection loop figure 4 1 which reduces 10 kc power The amount of dc power in the metering loop remains unchanged however and since this dc power controls the meter action the ambient temperature changes do not affect the meter indication The compensation capa bility depends upon the match of thermistor tempera ture characteristics When thermistor mounts are built the thermistors are selected to insure optimum match of thermal characteristics 01370 2 4 6 CIRCUIT DESCRIPTION 4 7 RF BRIDGE CIRCUIT 4 8 A Simplified schematic diagram of the rf bridge circuit is shown in
63. cy range Table 1 2 gives thermistor mount operating frequency mount configuration and operating resistance Specifications Weight Net 8 lb 3 63 kg with cover and cables 11 1 2 lb 5 44 kg including battery shipping approx 13 lb 5 9 kg Accessories Furnished 5 ft 1 5 m cable for temperature compensated thermistor mounts 7 1 2 ft 2 3 m power cable NEMA plug Accessories Available 431A 95B Rechargeable Battery Pack for field installation j Models 478A and 486A Thermistor Mounts 9 Model 8402A Power Meter Calibrator fg Model 01 8401 Leveler Amplifier Options 01 Rechargeable battery installed provides up to 24 hours continuous operation 02 Rear input connector wired in parallel with front panel input connector 10 With 20 foot cable for 100 Q or 200 mount 11 With 50 foot cable for 100 12 With 100 foot cable for 100 13 With 200 foot cable for 100 21 With 50 foot cable for 200 22 With 100 foot cable for 200 23 With 200 foot cable for 200 mount mount mount mount mount mount 1 1 Section I Paragraphs 1 5 to 1 11 Table 1 2 Mode1 431B Thermistor Mounts Type Operating Frequency Resistance Range in ohms Coaxial Waveguide p 478A 10 mc to 10 gc 200 L6 to 95 gc S486A 0 J486A 5 3 to 8 2 gc C H486A 7 05 to 10 0 gc K486A 18 0 to 26 5 td K486AC R486A 26 5 to 40 0 td RA86AC With circular contact flange adapter 1 5 The Mo
64. d MARCH Je 01370 3 Model 4918 Appendix APPENDIX MANUAL CHANGES This manual describes directly instruments with serial prefix 451 For other serials change the manual as indicated below If your serial prefix does not appear either here or on a change sheet supplied with the manual the correct information can be obtained from your nearest Hewlett Packard Field Office see lists on following pages Serial Prefix 432 Table 1 1 Change Zero Carry Over to read Less than 1 of full scale when zeroed on most sensitive range Paragraph 1 3 last sentence change to read within 1 for all higher power ranges Paragraph 3 2 second sentence change to read from range to range within 1 of full scale Figure 3 2 item 8 Note change to read Zero set accuracy of 1 be obtained Paragraph 5 74c Change last sentence to read zero must carry over from range to range within 1 of full scale Serial Prefix 221 223 and 301 Make above changes plus Figure 5 3 Q106 Change type to 1854 0003 Table 6 1 0106 Change hp Stock No to 1854 0003 Table 6 2 1854 0003 Change TQ to 3 1854 0045 Delete 01370 3 1 1
65. dc is known c the actual operating resistance ofthe thermistor and d the actual ratio of current division in the rf bridge 3 20 With precision components in the substitution setup and careful procedure error produced by the Model 431B Power Meter can be reduced to 1 or less This is assuming nominal thermistor mount resistance 100 or 200 ohms and that half the applied dc flows through the rf thermistor The dc substitution tech nique using the Model 431B is shown in figure 3 3 3 21 EQUIPMENT USED FOR DC SUBSTITUTION 3 22 The Model 8402A Power Meter Calibrator was Specifically designed to be used for calibration and dc substitution measurements of rf power addition the instrument will accurately measure the operating resistance of the thermistor mount being used Use the procedures given the manual provided with the Model 8402A Power Meter Calibrator to perform the dc substitution measurements 3 23 Althoughthe most convenient and accurate means of applying the dc substitution technique is by using Model 8402A Power Meter Calibrator it is also possible to accurately measure power using the dc substitution technique with the arrangement shown in figure 3 3 The digital voltmeter is used to monitor the substitution current The power supply output and voltmeter input are ungrounded to eliminate ground currents 3 24 ADDITIONAL APPLICATIONS 3 25 At the RECORDER output the Model 431B fur nishe
66. del 431B has provisions for using the dc substitution method of measurement and for check ing calibration accuracy of the power meter The dc substitution method of measurement which requires other equipment provides greater power measurement accuracies than can be obtained by the power meter 1 2 Model 431B alone In additiona jackin series with the panel meter permits digital or chart recording of measurements operation of alarm or control systems and use in a closed loop leveling system 1 6 ACCESSORIES 1 7 Two accessories are supplied with the Model 431B Power Meter a 7 1 2 foot detachable power cable and a 5 foot cable that connects the thermistor mount to the Model 431B Thermistor mounts are available see table 1 2 but not supplied with the instrument A rechargeable battery with installation kit is also available A list of supplied and available accessories is given in table 1 1 Specifications 1 8 INSTRUMENTS WITH OPTIONS 1 9 The options available with the Model 431B Power Meter are given in table 1 1 The thermistor mount cable options require modification and recali bration of the Model 431B Power Meter The recali bration procedures for the cables are given in section V Maintenance under Oscillator Frequency Adjust ment paragraph 5 58 and Coarse Null Adjustment paragraph 5 63 1 10 INSTRUMENT IDENTIFICATION 1 11 Hewlett Packard uses atwo section eight digit serial number 000 00000 If the
67. e Oper ating Notes for each instrument Complex procedures and special equipment are needed for some of these operations Therefore if the trouble proves to be a thermistor mount contact an field office for assist ance Except as stated in the Operating Note DO NOT ATTEMPT TO REPAIR THE THERMISTOR MOUNT 5 4 COVER REMOVAL AND REPLACEMENT 5 5 Refer to figure 5 1 when removing instrument covers Removal of the top cover exposes the circuit areas shown in figure 5 2 Routine checks and adjust ments can be performed without the removal of other covers However operations such as soldering on Instrument Type DC voltmeter Table 5 1 DC voltage measurement Calibration accuracy check Calibration accuracy check Precision milliammeter or Power Meter Calibrator Milliammeter O circuit check Power supply ripple check 10 oscillator amplifier check 10 kc amplifier check 10 kc amplifier null adjust Oscilloscope or AC voltmeter 01370 2 the circuit board and removal of the meter RANGE POWER or MOUNT RES switch would require the removal of the bottom cover and one or both of the side covers 9 6 COVER REMOVAL a At the rear of the instrument remove the two screws which retain the cover b Grasp the cover from the rear slide it back 1 2 inch then tilt forward edge of the cover upward and lift the cover from the instrument 5 7 TOP COVER REPLAC
68. ent TQ column 6 3 Miscellaneous parts not indexed in Table 6 1 are listed at the end of the table 6 4 ORDERING INFORMATION 6 5 To order a replacement part address order or inquiry to your nearest Hewlett Packard field office 6 Specify the following information for each part Model and complete serialnumber of instrument 6 a b Hewlett Packard stock number c Circuit reference designator Description 6 7 To order a part not listed in tables 6 1 and 6 2 give a complete description of the part and include its function and location REFERENCE DESIGNATORS assembly F fuse P plug V vacuum tube neon B motor FL filter Q transistor bulb photocell etc m gt x R resistor n cable DL delay line L 2 XF Duseholder DS device signaling lamp meter switch XDS lampholder E misc electronic part MP mechanical part transformer Z network ABBREVIATIONS A amperes F farads normally closed S B siow blow BP bandpass FXD NE neon SE selenium BWO backward wave normally open section s oscillator a positive zero SI silicon glass zero temperature SIL silver C i CER SRD our coettielent t COEF coefficient NSR not separately tantalum H henries replaceable COM common HG MEP TD time delay composition HR i Nude OBD
69. hecks Test Point DC Voltage Limits Voltage Out of Limits Check Emitter of 0101 1 5 to 2 5 C112 R116 R115 C110 Q101 Collector of Q101 4 5 to 6 0 Q101 C113 R117 to R124 Positive end of C116 3 5 to 4 5 Q103 R132 Q102 C115 Table 5 7 DC Voltages in Squaring Circuit Test Point DC Voltage Limits Voltage Out of Limits Check Cathode CR113 10 30 to 10 46 CR113 R167 R173 Cathode CR112 8 50 to 9 64 CR112 R174 R168 Cathode CR111 6 41 to 6 51 CR111 R175 R169 Cathode CR110 4 39 to 4 47 CR110 R176 R170 Cathode CR109 2 48 to 2 52 CR109 R177 R171 Cathode CR108 0 08108 CR109 to CR113 01370 1 5 5 Section V Model 431B Paragraphs 5 25 POWER DC METERING AND R13 SUPPLY RI79 FEEDBACK CIRCUITS 18V REG AOV BATTERY TERMINALS RI4I SYNCHRONOUS DETECTOR IOKC OSC AMP AND IOKC RF BRIOGE AMPLIFIERS AND METERING BRIDGE L10 C105 Cio ci04 SQUARING CIRCUIT 1 02 MP 5 1149 Figure 5 2 View b Using the dc voltmeter measurements at the points listed in table 5 5 the presence of 10 kc signal interferes with the dc measurements the 10 kc oscillator can be disabled without appreciably affecting the dc voltages by grounding the collector of Q109 DC voltages are measured with reference to the Model 431B ground 5 25 STEP 3 If there is no 10 kc output from the oscillator amplifier proceed as follows a Disconnect the thermistor mount 5 6 b Disco
70. hia Pa james Knights Co Sandwich 11 Electric Corporation Mt Vernan Lenz Electric Mig Co Chicago Lettlefuse luc Des Plaines M Lord Mtg Co Ene Pa C W Marwedel San Francisco Cali General Instrument Corp Micamold Div James Mig Co Inc JW Millet Co Monadnock Mills Mueller Electric Co Oak Manufacturing Co The Bendix Corp Bendix Pacific Div Pacitic Metals Co Phanostsan Instrument and Electronic Co South Pasadena Calit Philadelptua Steel and Wire Corp Philadelphia Machine amp Foundry Co Potter amp Brumfield Div Princeton las Electronic Components Div Camden N J General lasitument Corp Rectitier Div Brooklya Kartisburg Torrance Caid Newark Maiden Mass Los Angeles Calif San Leandio Calit Cleveland Qhio Crystal Lake It No Hollywood Calif San Francesco Cali Resistance Products Co Rubbercraft Corp of Calf Shakeprool Division 11 015 Tool Works Elgis IH Signal indicator Corp New Stathers Duna nc Pitman Thompson Bremei Co Chicago 11 Tilley Mg Co Stackpole Carbon Co Standar Thomson Corp Tionerman Products Inc Transtotmet Engineers Ucimte Co Waides Kohinoo nc Veedes Root Int Wenco Mfg Co Continental Witt Electronics Coro Philadelphia Pa Nea Rochelle X Y San Francisco Calst 1 Marys Pa Waltham Mass C
71. hs 3 15 and 3 17 Figure 3 2 Turn On and Nulling Procedure 01370 3 Section Figure 3 3 o POWER SUPPLY 0 300vde accuracy 0 2 6 405BR CR DTILA With power supply turned off connect the Model 431B as shown above Set the Model 431B for normal operation on the appropriate range using the procedure given in figure 3 2 Apply rf power at the thermistor mount and note and record the reading of the Model 431B meter This is the reference for the substi tution measurement Note A second digital voltmeter in parallel with a 1000 ohm 10 1 watt resistor connected in series with the RECORDER output of the Model 431B will increase accuracy of reference duplication Turn off or disconnect the rf source Turn power supply on adjust the output voltage of the power supply until the reference of step 3 is duplicated A potentiometer arrangement may be substituted for the adjustable power supply However at least 10 000 ohms must remain in series with the supply IK 05 IW IOK 10 IOW Model 4918 DIGITAL VOLTMETER MODEL 4318 POWER METER DC CALIBRATION SUBSTITUTION DO 536 DO CAUTION Never apply more than 20 ma de to the DC CALIBRATION amp SUBSTITUTION termi nals of the Model 431B 6 Readthe voltmeter which monitors the substitu tion current The voltmeter reading can be interpreted as current in milliamperes because
72. ifier It must be less than 12 mv peak to peak if not 10 kc oscillator amplifier gain is incorrect The cause could be 9108 Q109 C124 L101 L105 or T101 IfT101 is the cause of trouble use a special soldering tip to remove it from etched circuit board see table 5 1 01370 2 Model 431 Section V Tables 5 3 5 4 5 5 Table 5 3 Power Supply DC Voltage Checks DC Voltage Limits Voltage Out of Limits Check 38 to 43 ac line voltage CR1 4 24 to 27 ac line voltage CR2 CR3 C2 battery 10 7 to 12 3 CR8 6 0 to 7 5 CRT Q3 18 R13 Q5 Q2 18 3 to 18 6 Q1 Q3 02 24 0 25 6 CR9 POWER switch 1 4to 1 5 CR5 CR6 Test Point Minus end of Minus end of C2 Anode of CR8 Anode of Minus end of C6 Base of Q1 Anode of CR9 Plus end of C1 Table 5 4 Power Supply Ripple Checks AC Voltage Limits Test Point Voltage Out of Limits Check Minus end of C1 1 8 v max 5 v max CR1 CR4 C1 Minus end of C2 1 1 v max 3 v max CR2 CR3 C2 C6 Q13 Minus end of C6 10 6 mv max 30 mv max Ql to Q5 CR15 C2 C6 Table 5 5 10 KC Oscillator Amplifier DC Voltage Checks Test Point DC Voltage Limits Voltage Out of Limits Check Collector of Q110 18 Power Supply Emitter of Q109 10 0 to 14 0 Q108 Q109 C122 C121 Minus end of C121 5 0 to 6 5 C121 Q108 R153 Table 5 6 10KC Amplifier DC Voltage C
73. ignal provided by the Model 431B can be used to actuate alarm or controlcircuits Ar rangement of equipment to provideanalarmor control System is Shown in block diagram form in figure 3 7 3 30 DETERMINING INSERTION LOSS OR GAIN AS A FUNCTION OF FREQUENCY Arrangement of a System to obtain information on insertion loss or gain as a function of frequency is indicated in figure 3 8 Initially the device under testis not connected into the SyStem connect the thermistor mount directly to the Sweep oscillator Set the sweep oscillator forthe band of interest and record variations in amplitude as frequency is swept this curve is the reference Next insert the device under test between the sweep oscillator and the thermistor mount and again record frequency response The difference between the second reading andthe reference at any one frequency is the insertion loss or gain of the device at that frequency RECORDER J102 TEMPERATURE GO MODEL 4318 DHOI 8401A POWER LEVELER THERMISTO METER AMPLIFIER MOUNT ATEA 486A AMPLITUDE MODULATION INPUT RF POWER SOURCE DIRECTIONAL COUPLER CONTROL VOLTAGE NEGATIVE FEEDBACK 80 5 2454 Figure 3 6 Leveler Setup 3 6 01370 3 Section III 1 431B Figures 3 7 and 3 8 TEMPERATURE RECORDER ALARM COMPENSATED o DC CONTROL POWER RELAY PROTECTIVE OR THERMISTOR METER CORRECTIVE
74. iis Mirs North Hulls Electronics Glen Cove N Y Semiconductor Div of Clevite Corp Wakhan Mass taternationa Etectronic Research Corp Bubana Cad Columbia Technical Corp New York N Y Varian Associates Palo Alto Calil Marshali nd Elect Products Div San Mire Call Control Switch Division Controls Co ol America EI Segunuo Cart Delevan Eleclionmies Corp East N Y Wilco 5 md Renbrandt luc Boston Mass Holfrian Electromes Corp Seniconduclor Div Technology Instrument Corp of Calf Newbury Pata Cala El Maule Cal THE FOLLOWING H P VENDORS HAVE X0 Ni BER ASSIGNED IN THE LATEST SUPPLEMENT Y3 THE FEDERAL SUPPLY CODE FOR MANUFAC TURERS HANDBOOK 0000F 1000 00002 900 000 000 00088 000 OOONN 00000 00055 0008 DOGYY Malco Tool and Die Los Angeles Ca Western Coi Div Automalic ind Inc Redwood City Ca Willow Leather Products Corp Newatn NJ British Radio Clecuonics Lid Washinglan D C ETA Stemens Ameiica Components Dev Precision lastiumest Componeals Co Rubbe Eng amp Dcvetopureni AN D Mfg Ca Cooliron Conti ot Elgin Walch Co California Eastern Lah S K Co White Plas N v Var uvs Cub Hayward Call San Jose Cal 3 Q slau2 Quibana Cat Burtingloo Ca Los Angeles Cals From FSC Hasdbuok Supytenents Dated DECEMBER tind 42 Date
75. ing error signals inter act loss cannot be calculated from the swr figure it can only be expressed as lying between two limits Limits of mismatch loss generally are determined by means of a chart such as the Mismatch Loss Limits chart included in each of the thermistor mount Operating Notes A tuner such as the Model 872A or 870A can be used to minimize loss although the tuner itself will introduce some loss b Bolometer Mount Efficiency and Substitution Error Not all the rf power applied to the mount is used to heat the rf thermistor Some of it is absorbed by the other elements in the mount such as the walls of the rf chamber the heat sinks the leads etc Sub stitution error results because rf power does not affect the thermistor to the same degree as dc power Sub stitution error and mount efficiency are often combined forsimplicity of measurement into what is termed calibration factor Typically the calibration factor of the Model X486A waveguide mount is 97 to 98 3 1 Section Figure 3 1 3 2 THERMISTOR MOUNT O VERNIER ZERO amp 4318 POWER METER POWER OFF ac BATTERY Om CHARGE O CHANGE POWER The POWER switch sets up connections to the selected power sources or to the battery charging circuit When the power switch is in the AC position externally supplied 115 or 230 volts is applied to the instrument Ifthe instru ment contains a battery a tric
76. ing for temperature com pensated mounts Power Ranges 7 ranges with full scale readings of 10 30 100 and 300 uw 1 3 10 mw Also calibrated in dbm from 20 to 10 External Bolometer Temperature compensated thermistor mounts required for operation 478A and 486A series Accuracy 3 of full scale from 20 C to 35 C 5 of full scale from 0 C to 55 C Zero Carry Over Less than 0 5 of full scale when zeroed on most sensitive range Recorder Voltmeter Output Phone jack on rear with 1 ma maximum into 1000 ohms 10 one side grounded Calibration Input Binding posts on rear for calibration of bridge with 8402A Power Meter Calibrator or precise dc standards Power Supply 115 or 230 volts 10 50 to 1000 cps 2 1 2 watts Dimensions 6 17 32 in 166 mm high 7 25 32 in 198 mm wide 12 1 2 in 318 mm deep 01370 3 electrically isolated One thermistor is used to absorb rf power the other is used to provide temper ature compensation Thus the thermal drift problems normally associated with the thermistor power meter arrangement have been greatly reduced A Single setting of the ZERO control on the most sensitive power range is maintained within 0 5 for all higher power ranges 1 4 The temperature compensated thermistor mounts used with the instrument are specifically de signed for Model 431A B Power Meters Coaxial and waveguide thermistor mounts cover the 10 mc to 40 gc frequen
77. ing screws at the rear of the cover c Slide the cover rearward far enough to free its forward edge from the front foot assembly d Tilt the forward edge of the cover upward and lift the cover from the instrument 5 2 Range 10 to 1000 pf Capacitance per step 0001 u d Accuracy 1 decade General Radio Type 1419 B 5 9 COVER REPLACEMENT a Set the tilt stand as shown in figure 5 1 b Rest the bottom cover flat on the cast guides projecting inward near the bottom of each side frame see 2 figure 5 1 Slide the cover forward on the guides so that the formed portion at the rear of the cover slides over the two short projections at the rear corner of each side frame see figure 5 1 Replace the two retaining Screws and the rear foot assembly 01370 2 Model 431B 9 10 SIDE COVER REMOVAL 5 11 The side covers cannot be removed untilthe top and bottom covers are off see paragraphs 5 6 and 5 8 Each side cover is held in place by four screws retained by nuts which are not fastened to the side frames Note Replace side covers before replacing either the top or the bottom cover 5 12 TEST EQUIPMENT 5 13 Any instruments which satisfy the specifications of table 5 1 can be used for thetests described in this maintenance section 5 14 TROUBLESHOOTING 5 15 The first step in troubleshooting the Model 431B Power Meter should be isolation of trouble to the
78. is a block diagram which shows the Model 431B Power Meter and its associated thermistor mount The thermistor mount contains twothermistor elements and Rc Thermistor element Rg absorbs the rf power applied to the mount thermistor element Rc converts the applied rf power toa meter indication and provides compensation for ambient temperature changes at the thermistor mount 4 3 The power meter circuitry incorporates two bridges which are made self balancing by means of separate feedback loops Regenerative positive feed back is used in the detection loop degenerative feed back in the metering loop One thermistor element is used in one arm of each of the self balancing bridges In the detection loop the 10 kc oscillator amplifier supplies enough 10 kc power I19 ke tobias thermistor element Rq to the operating resistance which balances the rf bridge The same amount of 10 power is also supplied to thermistor element Rc by the series con nected primaries of transformers T101 and T102 4 4 When rf power is applied to thermistor element Ra an amount of 10 kc power equal to the rf power is removed from thermistor element Rq by the self balancing action of the rf bridge Since the primaries of T101 and T102 are series connected the same amount of 10 kc power is also removed from thermistor element R thus the action which balances the rf bridge unbalances the metering bridge The metering bridge loop automatically re balan
79. kle charge is applied to maintain the battery at full charge With POWER at BATTERY ON a 24 vdc battery within the instrument supplies primary power to the instrument With POWER at CHARGE 115 and 230 volt power is used to charge the battery 16 to 24 hours is required to obtain full battery charge The instrument is operative in this position Note Batteries are installed at the factory for option 01 instru ments only RANGE The RANGE switch can be set for full scale power readings from 01 to 10 milliwatts in seven steps It also includes a NULL posi tion which in conjunction with the adjacent null screwdriver adjust insures that the meter ing bridge is reactively balanced The THERMISTOR MOUNT connector is a female receptacle that accepts a specially made cable whichis supplied with the instrument cable connects the mount thermistors into their respective bridges within the power meter Model 431B THERMISTOR MOUNT OC CALIBRATION LINE 8 SUBSTITUTION VOLTAGE MOUNT RES This two position slide switch sets the power meter to accommodate therm istor mounts of 100 or 200 ohm nominal resistance ZERO and VERNIER The ZERO control coarsely sets the meter pointer near zero the VERNIER control is a more exact adjustment which sets the meter pointer on zero In Option 02 instruments only mount connector wired in parallel with front panel connector Two mounts cannotbe connected simultaneously
80. le unit it can be bench or rack mounted analogous to any full module instrument An illustration of the combining case is shown in figure 2 1 Instructions for installing the Model 431B in a combining case are given graphically in figure 2 2 2 8 ADAPTER FRAME The adapter frame is a rack frame that accepts any combination of sub modular units It can be rack mounted only An illustration of the adapter frame is given in figure 2 3 To assemble refer to Figure 2 4 and proceed as follows a Place the adapter frame 1 on edge of bench as illustrated b Stack the submodular units 2 in the frame Place the spacer clamps 3 between instruments d Place spacer clamps 4 on the two end instru ments e Push the combination into the frame DIVIDER ASSEMBLY razioni RETAINER MP S 1178 Figure 2 i The Combining Case 01370 3 2 1 Section II Paragraphs 2 9 to 2 13 STEP 1 SLIDE TOP PART TO LIMIT STEP SLIDE BOTTOM PART TO LIMIT 3 PUSH IN TO LIMIT STEP 4 SLIDE OVER TO LIMIT Model 431B PUSH DOWN TO RELEASE 6 PLACE INSTRUMENT INTO CASE 7 SET RETAINER BACK INTO PLACE STEP PUSH TO Figure 2 2 Steps to Place Instrument into Combining Case FILLER PANEL Figure 2 3 Adapter Frame Instrument Combinations 2 2 f Insert screws 5 on both sides of frame and tighten until submodular instruments
81. leveland Ohio San Gabriel Calif Newtonville Mass Long island City N Y Hartford Conn Chicago Ul Mtg Corp Mepco Division of Sessions Clock Co Morristown Schnitzer Alloy Products Co Elizabeth Times Telephoto Equipment New York N Y Electronic Industries Association brand Tube meeting ELA standar s Washington D C Unnar Switch Dev Maxon Electonics Corp United Transforme Coro Oxford Electric Corp Bourns Laboratories Inc Robeitshaw Conzols Co All Star Products Iac Avery Adhesive Label Cosp Wallinglord Conn New Yoik N Y Chicago il Cats Hillsboro Ohio Ohio Montovia Calit From FSC Handbook Supplements H Dated DECEMBER 1954 4 Dated MARCH 1962 6 11 Section VI Table 6 3 Code No Barry Contigis Div Barry Wught Waterton Mass 32642 Prec sion Electric Skox e Itl k2G47 Sperti Faraday lat Hewit lecinc Dov Hoboker N J 97142 Jelles Electronics Dives ca Speet Carmen Dr Boos Pa 22175 fach 8 Caneira Inst Carp Delense Prod Division N J 22723 Magus Indusines Inc Greenwich Conn 62249 Sylvan Eiectne Proc luc Etectroure Tute Division Emporium Pa 52315 Astron Division Renwel Industries lac East Newark N f 2389 Switch ialt Inc Chicago Ill 8264 Metals amp Conlrols Inc Spence Products Attleboro Mass 62765 Phe
82. lips Advance Cantsol Co Jelet 2866 Researzh Products Corp Madison Wis 22877 Rolron Mig Co Inc Waccslocx 82992 Veclor Electrenic Co Glendale Calil 82252 Wester Washer Mig Co Los Angeles Calif 23093 Can Fastener Co Canbridge Mass 53985 New Himashere Ball Bearing Inc Peterborough N H 83123 General Instrument Corp Capacitor Div Dar ington S C 32143 ITT Wire ana Cable Ov Los Angeles Cant e3l6b Victory Eng neering Spiinglield NJ 53298 Bendix Corp Red Bank Ow Banx N J 63315 Hubbel Core Mundelein LIL 43336 Swith derman H Inc Biooalyn N Y 2285 Centra Screw Co Chicago NI 83901 Gavall Wire and Cable Co Div of Arierace Corp Brookfield Mass 81594 Burroughs Corp Electronic Tube Div Plaintietd N J 83732 Eveready Div Nationa Carbon Div Unon Carbide Coro New York N Y 8377 Rode Eng and Mig Inc Huntingtar dnd 56015 40 Monufacturer Address New York Bast n Mass Harvrarlung Co I Stevems Inc International Instruments Int Giuayhi Co Trag Tiasstgirer Corp Vence Calif Winchester Elections Co inc Norwalk Specstecation ee eee wiku Products Inc Cleveland Ohio International Rectil er Com E Segunda Calif The Apak Products Carbedge Mass Rev sec May 1965 6 12 Orange Con LaGrange 111 Code 3252 471 4296 84411 81970 89154 85471 85424 35063 8591 8
83. n the instrument a trickle charge is supplied to the battery In the BATTERY ON position instrument operation is entirely dependent on the battery In the CHARGE position 25 volts is connected to the battery for recharging the Model 431B cannot be operated during this time Approximately 37 ma dc is applied to the battery during charge time Section IV Paragraphs 4 36 to 4 37 40V FROM CR A CRS R4 A 25 VOC PEG CRY 25 FROM CR2 8 CR3 18 REGULATOR 1 5 VDC UNREG CENTER TAP OF TI SD_S 177 CR5 CRE Figure 4 10 Regulated Power Supply FI pie an Ji b Da 1 40 VOLT Re R3 18V REG RECTIFIER REGULATOR POWER O TRANSFORMER 25 VOLT RECTIFIER OPTIONAL BATTERY 1 5V UNREG CR5 CRE Figure 4 11 Power Switch Arrangement 01370 2 4 5 Section V Model 431B Figure 5 1 PLASTIC FOOT RELEASE BOTTOM COVER TILT STAND ASSEMBLY BUT TON REAR PANEL TOP COVER d SIDE COVER Figure 5 1 Cover Removal 5 0 01370 1 Model 431B Section V Paragraphs 5 1 to 5 7 SECTION V MAINTENANCE 1 INTRODUCTION 5 2 This section includes instructions and informa tion for the maintenance troubleshooting and repair of the Model 431B Power Meter 5 3 The testing and repair of Model 486 and 478A thermistor mounts are discussed in th
84. n conjunction with the first 10 kc amplifier Q101 and the RANGE switch to change metering loop gain so that the meter will read full scale for each power range Diode CR107 provides additional temperature compensation for Q107 4 25 METER CIRCUIT 4 26 The meter circuit is shown in figure 4 8 It includes feedback current squared generator Q106 a squaring circuit the meter and RECORDER jack J102 The purpose of the meter circuit is to convert a linear voltage function proportional to applied power to a squared function so that power may be indicated on a linear meter scale The linear voltage function is applied to the base ofQ106 and is converted to a square law function by the squaring circuit in series with Q106 emitter 4 27 SQUARING CIRCUIT The squaring circuit in cludes diodes CR109 113 and resistors R167 177 Temperature compensation for the squaring circuit is provided by CR108 4 28 The design of the squaring circuit is such that individual diodes conduct at discrete values of emitter voltage so that emitter conductance approximates a square law function Thus the collector current of Q106 is made to approximate a square law function and the meter indicates power on a linear scale 4 29 RECORDER OUTPUT The current which drives the meter can be monitored at the RECORDER output a telephone type two wire jack RESISTOR OF 1000 OHMS MUST REMAIN IN SERIES WITH THE METER FOR ALL APPLICATIONS USING THE METER DRI
85. nnect the positive lead of C125 from the circuit board c Make a direct connection between the positive lead of C125 and bridge side of C120 terminal 35 on the underside of the circuit board d Using the oscilloscope monitor the output of the oscillator amplifier If oscillation is present the metering and rf bridges should be examined for defect The waveform of the oscillation under this condition may show limiting 01370 1 Model 4518 9 26 If component replacement is required as a result of the foregoing tests note the following a After replacement of Q110 or Q111 check the amplitude of the 10 kc oscillator amplifier output paragraph 5 23a b If Q108 or Q109 has been replaced check the out put frequency ofthe oscillator amplifier para 5 23b After replacement of L105 or C124 readjustment of the oscillator frequency could be necessary See paragraph 5 58 for this procedure 5 27 10 KC AMPLIFIER CHECK 5 28 A voltmeter and oscilloscope are needed for checking the 10 kc amplifier Table 5 1 Test Equip ment gives equipment requirements Refer to figure 5 2 Top View for component location 5 29 Table 5 6 lists de voltage check points and possible causes for deviations from the given limits All voltages are referenced to the Model 431B ground If the presence of 10 kc signal interferes with dc measurement ground the center tap of L102 5 30 Calibration inaccuracy common to all powe
86. nt and rear panels of the instrument provided with the figure 3 7 OPERATING INSTRUCTIONS 3 8 Figure 3 2 Turn On and Nulling Procedure and figure 3 3 DC Substitution Technique give step by step instructions for operating the Model 431B In figure 3 2 each step is numbered to correspond with numbers on the accompanying drawing of the power meter 3 9 BATTERY OPERATION 3 10 The following applies to power meters having a factory or a field installed rechargeable nickel cad mium battery See figure 3 1 Turn On and Nulling Procedure for step by step instructions for operating the Model 431B from a battery 3 11 BATTERY CHARGING TIMES 3 12 The battery used in the Model 431B requires two hours of charge time for one hour of battery operation When the battery is fully charged the Model 431 can be continuously operated for 24hours with 48 hours of charge time However it is recom mended that battery operated instruments be operated for eight hour periods with a 16 hour recharge time This makes the Model 431B available for portable use daily yet maintains the battery at full charge 3 13 BATTERY CHARGE CHECK 3 14 Under normal conditions a fully charged battery will start at approximately 27 voits and drop to about 22 volts after 24 hours of continuous use at room temperature a Connect the Model 431B to ac primary power Set POWER to AC and perform the turn onand nulling 01370 3 procedure given in fig
87. o monitor current through the resistor Connect the Model 431B to the ac line set the POWER switch to BATTERY CHARGE and observe the reading of the current meter Charging current should be 27 to 40 ma 5 49 A battery which will not assume rated terminal voltage with proper charging current may have a defec tive cell or cells In such cases the battery must be replaced see section VI Table of Replaceable Parts 5 8 Mode1 431B 5 50 WARRANTY 5 51 warranty appearing the inside the rear cover of this manual also applies to the acces sory battery option 01 Within the warranty period the battery may be returned to Customer Service for repair or replacement 5 52 REPAIR 5 53 The etched circuit board used inthe Model 431B is of the plated through type which consists of a base board and conductor board does not include funneled eyelets The conductor material is plated to the wall of the holes thus the conductor is effectively extended into the hole This type of board can be soldered from either the conductor or component side of the board with equally good results The rules given below should be followed when repairing a plated through type etched circuit board a Avoid applying excessive heat when soldering on the circuit board b To remove a damaged component clip component leads near the component then apply heat and remove each lead with a straight upw
88. oscope or vtvm between ground and the lead of R138 nearest T103 d Mechanically center the null capacitor C103 by observing its rotor plates e Using the ZERO and VERNIER controls maintain on scale indication on the Model 431B meter while substituting values for C105 to obtain a minimum indication on the oscilloscope or vtvm f Adjust C103 the null capacitor to improve the minimum indication on the oscilloscope or vtvm The null capacitor should be near mid range Note A decade capacitance box can be used to de termine the value of capacitance to be added see table 5 1 g Set RANGE to NULL The Model 431B meter deflection should be less than 4 of full scale If it is not increase the value of C104 in approximately 50 pf increments to a maximum value of 500 pf If 100 and 200 ohm thermistor mounts are to be used repeat the null procedure for 100 ohm mounts paragraph 5 67 after each increase in capacitance of C104 5 69 ZERO AND VERNIER CONTROL ADJUSTMENT a Connect a de digital voltmeter see table 5 1 at the Model 4518 RECORDER jack Use a special telephone plug to dual banana plug cable assembly terminated with a 1000 ohm 0 1 0 25 watt wire wound resistor b Set Model 431B RANGE to 01 MW and adjust Model 431B ZERO and VERNIER controls for zero meter reading on the Model 431B Set Model 431B RANGE to 10 MW d Connect a decade resistance box across R141 see figure 5 2 and adjust to ob
89. pecifications The squaring circuit includes CR108 through CR113 and R167 through R177 Figure 5 2 Top View shows component location 01370 2 Section V Paragraphs 5 26 to 5 43 5 36 The Squaring circuit is tested under two condi tions 1 when all diodes are conducting and 2 when no diodes are conducting Both conditions should be used whenever the squaring circuit is tested 5 37 A digital voltmeter seetable 5 1 for specifica tions is recommended for the following measurements 5 38 DIODES CONDUCTING The following pro cedure measures the forward voltage drop of each diode in the squaring circuit a Set the Model 431B RANGE switch to 1 MW and adjust the ZERO and VERNIER controls for exact full scale deflection of the meter pointer b Disconnect the grounding link at the digital volt meter input and measure the voltage drop across the individual diodes of the squaring circuit The require ment is 0 4 to 0 5 vde 3 39 DIODES OFF The test points listed in table 5 17 the midpoints of five two resistor voltage dividers connected between 18 vdc and ground This check verifies that each diode is properly back biased a Adjust the Model 431B ZERO control for a below zero deflection of the meter pointer b Connect the voltmeter ungrounded input be tween the regulated 18 vdc supply and the test points listed in table 5 7 The voltmeter readings should be within the limits specified in the table
90. r ranges can be caused by the 10 ke amplifier In particular an out of tolerance resistor in the collector of Q101 or a defect in the Q102 stage which results in improper gain will produce calibration error 5 31 An open signal pathor very low gainin the 10 kc amplifier can drive the meter pointer to its downscale limit For signal tracing the 10 error signal from the metering bridge can be used or C110 can be discon nected and used as a means of injecting a substitute 10 ke test signal Note A special soldering tip is required to replace transformer T102 Refer to table 5 1 for the type of soldering tip to be used 5 32 METERING AND FEEDBACK CIRCUIT 5 33 Before performing this procedure refer to para graphs 5 69 and 5 70 and check values of R141 and R179 The differential amplifier 0104 and 9105 the feedback current squared generator Q106 the feed back current generator Q107 andthe squaring circuit comprise the metering and feedback circuit See figure 5 2 top view for component location Note Transistors Q106 and Q107 are selected for optimum calibration accuracy If Q106 or Q107 is replaced check calibrationaccuracy using procedure given in paragraph 5 76 or 5 78 It may be necessary to try several transistors to get proper calibration accuracy 9 34 SQUARING CIRCUIT CHECKS 5 35 A check of the squaring circuit is advisable if full scale or tracking accuracy ofthe Model 431B does not meet s
91. s a current 0 to 1 ma dc which is proportional to the power measured This feature makes possible a measurement system with more capability than simply the indication ofpowerona meter Some of the more Sophisticated measurement systems are shown in block diagram form in figures 3 4 through 3 8 3 26 PERMANENT RECORD Use of a recorder in the measurement system is indicated in figure 3 4 Resistance across the Model 431B RECORDER output should be 1000 ohms 10 for optimum measurement accuracy Any type of recorder may be used with the Model431B if input resistance exceeds 1000 ohms use a shunt across the recorder input Jio2 RECORDER fj MODEL 4318 METER 8D S 252 Figure 3 4 Making a Permanent Record 01370 2 3 5 Section Paragraphs 3 27 to 3 30 TEMPERATURE RF SOURCE fg MODEL 4318 COMPENSATED POWER THERMISTOR METER MOUNT gt 418A 4864 Model 431B f MODEL 405 DIGITAL VOLTME TER BD S 253 Figure 3 5 Obtaining Increased Resolution 3 27 INCREASED RESOLUTION Digital readout of power to three decimal places can be obtained with the arrangement shown in figure 3 5 The value of R1 is 316 2 ohms 1 and Ry is 1000 ohms 1 1 Correct placement of the decimal in the readout is determined by the setting of the power meter RANGE switch On the divider switch arrangement at the voltmeter input may be replaced by a single 1000 ohm 1 resistor With this arrangement on the 01 1 and 10
92. substitution using the equip ment and connections shown in figure 3 3 5 80 Using the data in table 5 8 the full scale cal ibration accuracy of each range and the tracking accuracy of the 10 mw range can be tested Table 5 8 Data for Calibration Tracking Accuracy Check Full Scale 8 mw 6 mw 4 mw 2 mw 01370 3 Test Point Substitution Current Iac Mount Res Mount Res 14 Model 431 Meter Reads 9 7 to 10 3 mw 7 8 to 8 2 mw 5 8 to 6 2 mw 3 8 2 1 2 0 0 0 0 0097 to 0 0103 mw Section V Mode1 431B Figure 5 3 WAVEGUIDE RF SHIELD ss NB sp TA n THERMAL CONDUCTING I ario TO Ne IOKC BIAS y 2 RF SIGNAL 3 P O AIO _ DC BIAS 4 ua ii DETECTION COMPENSATION THERMISTOR THERMISTOR I i j WAVEGUIDE THERMISTOR MOUNT S10 486A MOUNT RES J103 ET THERMISTOR RF SHIELD MOUNT COMPENSATION THERMIS TORS METERING BRIDGE Rios 189 0 y DETECTION THERMISTORS f Z Z 7 6 1 THERMISTOR i MOUNT C103 7 z 1 CABLE 7 144 NULL HERMAL CONDUCTING COAXIAL THERMISTOR MOUNT 478A NOTES B CONNECTION BETWEEN PIN 5 ON AND TERM 4 ON ASSY IN STANDARD 4318 8 OPTION IO ON OTHER OPTIONS NO CONNECTION i OPTION OPTION OPTIONS OPTIONS iO 1821 12822 15823
93. tain zero indication on Model 431B Power Meter e Note amount of resistance required from resis tance box to obtain zero indication f Remove the decade resistance box and replace with resistor of value noted in step e g Check the Model 431B range to range zero drift by 1 setting Model 431B RANGE to 01 MW and re adjusting its VERNIER for zero meter reading 2 switching the Model 431B through its complete range while observing the digital dc voltmeter reading Test limits digital dc voltmeter reading must not exceed 5 mv 0 005V on any Model 431B range 9 70 FULL SCALE ACCURACY ADJUSTMENT a Connect a Model 8402A see table 5 1 at the Model 431B POWER METER terminals Check that Model 8402A OUTPUT CURRENT is off 9 10 Model 431 b Set Model 4518 RANGE to 10 MW set Model 8402A RANGE MW to 10 MW and FUNCTION to CAL Adjust the Model 431B ZERO and VERNIER controls for a zero indication on the meter d Set Model 8402A OUTPUT CURRENT to ON connect decade box across terminals of R179 Adjust decade box for a reading of exactly 10 mw on 431B panel meter Switch Model 8402A to 8 mw 6 mw 4 mw then 2 mw Model 431B panel meter should track within 2 of full scale see table 5 8 Dis connect decade box e Set Model 8402A OUTPUT CURRENT to OFF f Set Model 431B RANGE to 3 MW set Model 8402 RANGE MW to 3 MW g Reset Model 431B VERNIER to zero the meter if necessary h Set Model 84
94. te RANGE through its 03 1 3 1 3 and 10 MW positions observing the accuracy of the zero setting at each position The zero must carry over from range to range within 0 5 of full scale 5 75 CALIBRATION AND RANGE TRACKING ACCURACY 5 76 Calibration and range tracking accuracy is verified by dc substitution Briefly dc substitution involves 1 applying enough direct current at the DC CALIBRATION amp SUBSTITUTION terminals to obtain the desired meter indication 2 accurately determining the applied current and 3 calculating the dc power applied The difference between the substituted de power and the meter indication it produced isthe cal ibration error The Model 8402A Power Meter Calibrator or other means of producing accurate direct currents is used as the substitution source Section V Paragraphs 5 75 to 5 80 5 77 CALIBRATION AND TRACKING ACCURACY TEST USING THE MODEL 8402A POWER METER CALIBRATOR The Model 8402A Power Meter Cal ibrator provides constant currents sufficient to cause full scale meter indication on each of the Model 431B power ranges It also has provision for checking the tracking accuracy of the Model 431B on the 10 mw range 5 78 Refer to the Operating and Service Manual of the Power Meter Calibrator for correct test procedure 9 79 ALTERNATE METHOD FOR CHECKING CAL IBRATION AND RANGE TRACKING ACCURACY The calibration and range tracking accuracy of the Model 431B can be checked by dc
95. thermistor mount and thermistor mount cable or tothe power meter itself The thermistor match check in the maintenance section of the Operating Note per taining to the thermistor mount in use will indicate a defective thermistor or thermistors A simple ohm meter continuity check and inspection of the thermistor mount cable and its connectors can be used to prove the cable Table 5 2 Section V Paragraphs 5 10 to 5 18 5 16 Table 5 2 Troubleshooting and the following detailed tests are given to aid in correcting trouble within the Model 431 To make localizing of trouble easier the 431B circuitry is divided into five sections the power supply the 10 ke oscillator amplifier in cluding the rf bridge the 10 amplifier including the metering bridge the dc metering and feedback amplifiers and the squaring circuit Tests are given for each of these sections 9 17 THE POWER SUPPLY 5 18 The de test point voltages shown on the power supply schematic diagram with two exceptions apply to instruments operated from either ac or battery pri mary power Voltage limits shown at C1 and C2 apply only to instruments operated from ac primary power Refer to figure 5 2 Top View for component location a Connect Model 431Btoa variable line transformer and set transformer for 115 vac 230 vac b Connect a dc voltmeter see table 5 1 for volt meter requirements between the negative terminal of C6 and Model 431B gro
96. tor Mount Completion of test See table 1 2 for list of suitable 9 478A 486A circuit mounts 10 kc oscillator amplifier check 10 oscillator amp lifier frequency adjust Frequency counter Variable Transformer 5 place readout Min input sensitivity 4 v rms Max frequency greater than10kc Accuracy better than 0 1 Power supply adjustment Range 43521C or E 9 5212A t 5512A 103 to 127 vac 3 7 1 2 amp 206 to 254 vac Q 4 amp General Radio type W10MT3A Voltmeter range 100 to 127 vac 200 to 254 vac Voltmeter accuracy 1 volt Soldering Iron amp Tips Resistor Charging checks Wattage rating 50 watts Min tip temp 8009F Tip size O D 1 16 to 3 32 Ungar 116 solder ing iron handle Ungar PL333 tiplet Ungar 854 Cup tip Value 780 2 Accuracy 1 Wattage 3 watts Resistor Charging checks Value 7500 2 Electra MF2 0 Accuracy 1 Wattage 2 watts Zero and vernier contro1 adjustment Full scale accuracy adj Decade Resistance Divider Zero and vernier control adjustment Precision Resistor Range 50 Q to 50K Q Multiple 10 0 Accuracy 1 per decade Value 1000 2 Accuracy 0 10 GR1432 P Decade Resistance Box Ultronex Type 205A Wattage 0 25 watts Oscillator frequency adjustment Coarse null adjustment Decade Capacitors 5 8 COVER REMOVAL a Set the tilt stand as shown in figure 5 1 b Remove the two retain
97. tot Western Corp Los Angeles Calif Mountains View Call Palo Atto Calif Rockaway Los Angeles Cali Pomona Calif Ti Tal Inc Berkeley Galit Carbarundum Co Niagara Falls N Y CTS of Berne Inc Beroe Ind Chicago Telephone of California Inc So Pasadena Calif Bay State Electronics Corp Waltham Mass Microwave Electronics Corp Palo Afta Duncan Electronics inc Costa Mesa Calif General Insitument Corp Semiconductor Div Praducts Group Newatk N J Imperia Electronic inc Buena Park Melabs Inc Palo Allo Cali Philadelphia Hardie Co Camden N J Clarostat Mfg Co Dover N H Nippon Electric Co Ltd Tokyo fapan Metex Electronics Corp Clark Detta Semiconductor Inc Newport Beach Calif Thermolloy Dallas Texas Telelunken G M 8 H Hanover Germany Midland Wsight Div of Pacific Industries inc Kansas City Kansas Rewbuiy Park Calit Santa Monica Cali Conshohocken Pa Loveland Colo Newark N J San Jose Cali New York NY K Hollywood Calif Sem Tech Calf Resisto Corp American Components Inc Hewlett Packard Company Cornell Dublies Electric Corp Williams Wig Co Webster Electronics Co Adjustable Bushing Co Micron Electronics Garden Lang tstaad N Y Twentieth Century Spring Co Santa Clara Amelco Inc Mt View Call Daven Div Thomas Edison Ind McGiaw Edison Co Long Island City N Y Speuce Pine Mic
98. und The voltage here should be 18 vdc adjust with potentiometer R13 c With the voltmeter connected as above test the regulation of the power supply for instruments Troubleshooting Trouble Indication Possible Cause Null impossible Meter does not indicate does not zero but does null Meter pointer drifts during readings Rotation of the ZERO or VERNIER control results in erratic movement of the meter pointer on the 01 MW range Movement of the thermistor mount cable causes ab rupt flicker of the meter pointer onthe 01 MW range Meter pointer stays down scale 01370 2 Thermistor mount Thermistor mount cable MOUNT RES switch T102 Q106 Thermistor mount Q106 0107 Thermistor mount in unstable thermal environment RF source unstable DC calibration substitution source unstable Oscillator amplifier 10 kc amplifier Interference from external 10 kc signal ZERO or VERNIER potentiometer Thermistor mount Thermistor mount cable T102 Thermistor mount Thermistor mount cable Power supply Meter RECORDER jack Q106 C102 C101 10 kc amplifier 5 3 Section V Paragraphs 5 19 to 5 24 Mode1 431B Table 5 2 Troubleshooting Cont d Trouble Indication Possible Cause Meter pointer stays up scale Calibration inaccurate all power ranges Calibration inaccuracy NOT all power ranges Zero setting does not carry over from range to range within specification operated from ac primary po
99. ure 3 2 This will check for normal operation from ac primary power Ifperform ance is normal proceed to step b b Set POWER to BATTERY CHARGE the AC CHARGE lamp will glow Allow Model431Bto charge the battery for 48 hours This will allow the battery to obtain a full charge c After the recharge interval set POWER to BATTERY ON Since battery is now fully charged you should be able to zero set and null the meter figure 3 2 If not the battery or battery charging circuit is at fault Refer to Battery and Charging Checks paragraph 5 40 3 15 MAJOR SOURCES OF ERROR MICROWAVE POWER MEASUREMENTS 3 16 In microwave power measurements the follow ing are the major sources oferror 1 mismatch error or tuner loss when a tuner isused to tune out mismatch error 2 bolometer mount efficiency 3 substitution error 4 instrument error and 5 error due to the unilateral properties ofathermistor Thus five errors must be known if accurate power measurements are to be obtained Expressed mathematically Total measurement error mismatch or tuner loss calibration factor instrument error error due to the unilateral properties of a thermistor a Mismatch Loss Unless the mount and rfsource are perfectly matched to the transmission system fraction of incident power is reflected and does not reach the thermistor Since there generally is more than one source of mismatch in a microwave meas urement system and the result
100. wer by varying the line voltage 10 about the nominal 115 or 230vac There should be no perceptible variation of the 18 vdc d If 18 volts cannot be obtained by adjustment of R13 or if regulation is not satisfactory proceed with the following test to determine the causes 1 Use a voltmeter see table 5 1 to check the ac voltage limits at the points listedintable 5 3 See figure 5 2 top view for component loca tion All voltages are measured with reference to the Model 431B ground 2 Check ripple voltages ac operation using an ac voltmeter or oscilloscope at the points listed in table 5 4 Table 5 1 gives require ments for the voltmeter or oscilloscope 5 19 If the power meter does not function normally e g pointer driven to its limits no power indication and power supply regulation isunsatisfactory another circuit area such at the 10 kc oscillator amplifier or 10 kc amplifier could be the cause 5 20 A 18 vde supply which is set high or low causes calibration inaccuracy of the Model 431B 5 21 10 KC OSCILLATOR AMPLIFIER CHECK 5 22 Tests of the oscillator amplifier should be made according to the step sequence in which they appear below dc voltmeter an ac voltmeter or oscil loscope and a frequency counter are needed for the tests see table 5 1 for test instrument specifications Figure 5 2 Top View shows component location 5 4 T102 Oscillator failure Thermistor mount cable

HP 431-PowerMeter-1

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