————— OPERATING AND SERVICE MANUAL 435B POWER METER (Including Options 001, 002, 003, and 004) SERIAL NUMBERS ‘This manual applies directly to instruments with serial numbers prefixed 2342A and 2342U. With changes described in Section VI, this man: | ual also applies to instruments with serial num- bers prefixed 205A, 2041 and 238A. For additional important information about serial numbers, see INSTRUMENTS COVERED BY MANUAL in Section 1. iz HEWLETT PACKARD © Copyright HEWLETT-PACKARD COMPANY 1980, 1963 4501 PAGE MILL ROAD, PALO ALTO, CALIFORNIA, U.S.A. OPERATING AND SERVICE MANUAL PART NO. 00435-0040, Operating Manual Part No. 00435-00061 Operating and Service Microtiche Part No. 00435-90042 Printed: FEBRUARY 1984® Model 4358 Safety Considerations SAFETY CONSIDERATIONS GENERAL ‘This product and related documentation must be reviewed for familiarization with safety markings and instructions before operation. This product is a Safety Class I instrument (pro- vided with a protective earth terminal). BEFORE APPLYING POWER Verify that the product is set to match the avail- able line voltage and the correct fuse is installed. SAFETY EARTH GROUND An uninterruptible safety earth ground must be provided from the main power source to the pro- duct input wiring terminals, power cord, or sup- plied power cord set. Any interruption of the protective (grounding) conducior (inside or outside the instrument) or disconnecting the protective earth terminal will cause a potential shock hazard that could resultin personal injury. (Grounding one conductor of a two conductor outlet is not sufficient protection). In addition, verify that a common ground exists between the unit under test and this instrument prior to energizing either unit. Whenever it is likely that the protection has been impaired, the instrument must be made inoperative and be secured against any unintended operation. If this instrument is to be energized via an auto- transformer (for voltage reduction) make sure the common terminal is connected to neutral (that is, the grounded side of the mains supply). Servicing instructions are for use by service: trained personnel only. To avoid dangerous elec: tric shock, do not perform any servicing uniess qualified to do so. Adjustments described in the manual are per- formed with power supplied to the instrument while protective covers are removed. Energy avail- able at many points may, if contacted, result in personal injury. Capacitors inside the instrument may still be charged even if the instrument has been discon- nected from its source of supply. For continued protection against fire hazard, re- place the line fuseis) only with 250V fuse(s) of the same current rating and type (for example, normal blow, time delay, ete.). Do not uge repaired fuses or short circuited fuseholders. SAFETY SYMBOLS AX, Instruction manual symbol: the product will be marked with this symbol when itis, necessary for the user to refer to the in- struction manual (see'Table of Contents for page references), ; Indicates hazardous voltages. Indicates earth (ground) terminal. ‘The WARNING sign denotes a (WARMING) sitar Itc attention procedure, practice, or the like, which, ifnot correctly performed oradhered to, could result in per- sonal injury. Do not proceed be- yonda WARNING sign until the indicated conditions are fully understood and met. ‘The CAUTION sign denotes a hazard. It calls attention to an operating procedure, practice, or the like, which, if not correctly performed or adhered to, could result in damage to or destrue- tion of part or all of the product. Do not proceed heyond a CAU- TION sign until the indicated conditions are fully understood and met. CAUTIONGeneral Information Model 4358 POWER SENSOR CABLE MODEL 4358 re ALIGNMENT TOOL POWER CABLE 1-0 Figure 1-1, HP Model 4358 and Accessories SuppliedModel 4358 General Information SECTION! GENERAL INFORMATION 14. INTRODUCTION ‘This manual provides information pertaining to the installation, operation, testing, adjustment and maintenance of the HP Model 435B Power Meter. Figure 1-1 shows the Power Meter with accessories supplied. An operating manual is shipped with the instru- ment. This is simply a copy of the first three sec- tions of thismanual. Theoperating manual should be kept with the instrument for use by the opera- ior. Additional copies of the operating manual may be ordered separately through your nearest Hewlett-Packard office. The part number is listed on the title page of this manual. On thetitle page of this manual, below the manual part number, is a “Microfiche” part number. This number may be used to order 100 x 150 mm (4x6- inch) microfilm transparencies of themanaul. The microfiche package also includes the latest Man- ual Changes supplement as well as all pertinent Service Notes. Instrument specifications are listed in Table 1-1. ‘These specifications are the performance stand- ards or limits against which the instrument may be tested, 1-2, INSTRUMENTS COVERED BY MANUAL Options 001, 002, 003 and 004 of the Power Meter are documented in this manual. The differences are noted in the appropriate location such as OPTIONS in Section I, the Replaceable Parts List, and the schematic diagrams. ‘This instrument has a two-partserial number. The first four digits and the letter comprise the serial number prefix. The last five digits form the se quential suffix that is unique to each instrument, The contents of this manual apply directly to in- struments having the same serial number pre- fix(es) as listed under SERIAL NUMBERS on the title page. An instrument manufactured after the printing of this manual may havea serial number prefix that is not listed on the title page. This unlisted serial prefix indicates that the instrument is different from those documented in this manual. The man- ual for this newer instrument is supplied with a yellow Manual Changes supplement that con- tains “change information” explaining how to adapt the manual to the newer instrument. In addition to change information, the supple- ment may contain information for correcting er- rors in the manual. To keep this manual as current and accurate as possible, Hewlett-Packard recom- mends that you periodically request the latest Manual Changes supplement. The supplement for this manual is keyed to the manual’s print date and part number, both of which appear on the title page. Complimentary copies of the supplement are available from Hewlett-Packard. For information concerning aerial number prefix not listed on the title page or in the Manual Changes supplement, contact your nearest Hewlett-Packard office, 1-3, DESCRIPTION ‘The Power Meter and a compatible power sensor are interconnected with the power sensor cable to form a power measurement system. The system power level range, frequency response, and load impedance are dependent on the power sensor. Accuracy of the power measurement system is, ensured by the following Power Meter character- istics: a, Aninternal automatiezeroing circuit which removes error dueto the ambient temperature out- put of the power sensor’s power sensing device. b, A calibration factor adjustment which ac: counts for error due to the frequency response of the power sensing device. ¢. Aninternal calibration reference which has an output of 1 mW + 0.7% (502). LaGeneral Information Model 435B Table 1-1, Specifications Frequency Range: 100 kHz to 26.5 GHz (depending on power sensor used), reve fo treba renee een cain ana ame cab vt fl scale Me sams 3,35 and dm Cav ow gta sr 4 8 with 9 cal ae rg i002, 00 and Bm een 1B 164 eer 068 with in aemonee oat 10-0, eta toaee cried att Win ba decocen th ei ofa ene ranges of gerbes yi niar ear ep apm ccbew a 0s. Aecuraey: instrumentation 1% of full sale on all ranges Zero: Automatic, operated by front-panel switch. Zero Set 20.5% of full scale on most sensitive ange, typical Zero Carryover: 20.5% of fall scale when zeroed on the most sensitive range. Noise typical, at constant temperature, peak | change over any oneminute interval); 20 pW {B484A), 40 nW (481A, B482A, S48BA, 8485A), {1 (B481HY, 84824, 40 uW 64818, 84828), trv hour, typical) at constant temperatare after 24-hour warcn-up); 40 pW (84844); 15 0 (BASLA, 84824, B489A, 84854); 1.5 AW (S481, 54824); 15 AW (6A81B, 84828) Power ferent: Internal 50 MEIz oscillator with ‘Type N Female connector on front panel {or rear panel, Option 068 only) Power output: 1.00 mW. Factory set to 0.7% traceable to tho National Burenu of Standards Accurney: #1.2% worst ease (20.9% rss) for one year (0 t0 55°C) SPECIFICATIONS Aesponse Time: (0 to 99% of reading, five time constants.) Range 1 (most sensitive) <10.0 seconds. Range 2 <3. seconds, Range 3 1.9 seconds. Ranges 4—10 -=500 milliseconds, ‘Typical, measured at recorder output) al Factor: 16position switch normalizes meter reading to account for calibration factor or effective eff cieney. Range 85% to 100% in 1% steps. Cal Adjustment: Front panel adjustment provides capability to adjust gain of meter to match power sensor in Recorder Output: Proportional to indicated power with 1 volt cor | responding to full scale; 1 kf output impedance: BNC connector. AF Blanking Output: Provides a contact closure to ground when auto- zero mode is engaged. Power Consumption: 100, 120, 220, or 240V +5%, 10%. 100 and 120 volts, 48 to 66 Hz and 360—~440 Hz. 220 and 240 volts, 48 to 66 He. 20 V-A maximum. Weight Net, 2.7 kg (6.9 Ibs). Dimensions: | 155 mm high (68/32 inches), 180 mm wide (5-1/8 inches). 279 mmn deep {11 inches). Includes aneornontineadty. Adld-+2, 1% ontoptworanges when uring the MSA, 482A, 5480A and BASTA power senses: rae eee ing ie ait BandWs2B power senses ad =.0%onthetop oranges when using theb4e1H ahd BZ power acnaor. honeModel 435B 1-4, OPTIONS 4-5, Battery ‘The Model 435B, Option 001 Power Meter is sup- plied with a rechargeable battery that provides up to 16 hours continuous operation from a full charge. If the Power Meter was purchased without the battery option, it may be ordered in kit form under HP part number 00435-60012. The kit includes the battery, the battery clamp, a 6-32 x 1/2-inch pan head machine screw and installation instructions. 1-6. Input-Output Options Option 002, A rear panel input connector is connected in parallel with the front panel input connector. Option 003. A rear panel input connector is con- nected in paralle! with the front panel input con- nector. A rear panel POWER REF OUTPUT con- nector replaces the standard front panel con- nector. Option 004, The 1.5 metre (5 ft.) power sensor cable is not shipped with the Power Meter. 4-7, ACCESSORIES SUPPLIED The accessories supplied with the Power Meter are shown in Figure 1-1. a, The 1.5 metre (5-foot) power sensor cable, HP part number 11730A, is used to couple the power sensor to the Power Meter. The 1.5 metre cable is omitted when Option 004 is ordered. b, ‘The line power cable may be supplied in sev- eral configurations. Refer to the paragraph en- titled Power Cables in Section II. 1-8. EQUIPMENT REQUIRED BUT NOT SUPPLIED. ‘To form a complete RF power measurement sys- tem, a power sensor, such as the HP Model 881A, must be connected to the Power Meter via the power sensor cable. General Information 1-9, EQUIPMENT AVAILABLE The HP Model 11683A Range Calibrator is recom- mended for performance testing, adjusting and troubleshooting the Power Meter. The Power Meter’s range-to-range accuracy and auto-zero operation can easily be verified with the calibra: tor. It also has the capability of supplying a full scale test signal for each range. ‘An extender board (HP part number 5060-0630) may be used to place the Ad assembly printed circuit board in a position that allows easy acces to test points and components. ‘The following table lists the power sensor cable aceessories and their lengths that are available for use with the Power Meter. Order option 004 if the standard 1.5 metre cable is not desired with a cable accessory. Power Sensor Cable Accessory | Cable Length 117308 3.1m (10 u7a0¢ 0) 117300 15.2m (50 f) 17306 30.5m (100 0) 11730F 1.0m (200 #0) 4-10, RECOMMENDED TEST EQUIPMENT The test equipment shown in Table 1-2 is recom: mended for use during performance testing, adjust ments and troubleshooting, To ensure optimum performance of the Power Meter, the specifica- tions of a substitute instrument must equal or exceed the critical specifications shown in the table. 1-11, SAFETY CONSIDERATIONS ‘The Power Meter is a Safety Class I instrument (provided with a protective earth terminal). This instrument has been designed according to inter national safety standards and has been supplied in safe condition. 1aGeneral Information Table 1-2. Recommended Test Equipment Model 4353 Instrument Type cr 1 Specifications ‘Suggested Model a Digital Voltmeter | i Function: DC, Resistance Ranges: Resistance: 200 2 ‘Vale: 100 mV, 1000 mV, LOV, 100V 10M input impedance 51/2 digit resolution ‘Accuracy: #9.05% of reading 40.0280 of range HP 24564 | PLAT Vertical sensitivity: 0.2 V/division Horizontal sensitivity: 1 ms/division Frequency | Frequency Range: 200 Ha — 50 MElz HP 53144, A Counter Sensitivity: 100 mVrms | Accuracy: 0.01% Oscilloscope Bandwidth: de to 50 MHz HP 1740, | Power Meter ‘Range: capability to measure 1 mW ‘Transfer Aceuracy {input to output): HP 43 Power Sensor | Range: capability to measure 1 mW HP 451A/Hor) P,A HP 8482/1 Range Calibrator HP 116838, ‘Thermistor Mount SWR: 1.05 at 50 MHz. ‘Accuracy:** 20.0% at 50 MHz HP 4TeAHS | PLA +P =Performance Tests, A= Adjustment; T= Troubleshooting + traceuboto NBS:Model 4358 Installation SECTION II INSTALLATION 2-1. INTRODUCTION ‘This section includes information on the initial inspection, preparation for use, and storage and shipment instructions for the Power Meter. 2-2. INITIAL INSPECTION WARNING To avoid hazardous electrical shock, do not perform electrical tests when there are signs of shipping damage to any por- tion of the outer enclosure (covers and panels). Inspect the shipping container for damage. If the shipping container or cushioning material is dam- aged, it should be kept until the contents of the shipment have been checked for completeness and the instrument has been checked mechanically and electrically. The contents of the shipment should be as shown in Figure 1-1. Procedures for checking electrical performance are given in See- tion IV. If the contents are incomplete, if there is mechanical damage or defect, or if the instrument does not pass the electrical performance tests, no- tify the nearest Hewlett-Packard office. If the shipping container is damaged, or the cushioning material shows signs of stress, notify the carrier as well as the Hewlett-Packard office. Keep the shipping materials for the earrier’s inspection. 2:3, PREPARATION FOR USE 2-4, Meter Zeroing With the LINE switch set to OFF, the meter point- or should be positioned directly over zero. Ifneces. sary, insert a screwdriver into the mechanical Meter Zero control (beneath the meter) and align the pointer with zero. Back the adjustment off slightly. The backlash in the control ensures against a meter indication error caused by jarring the instrument. 25. Range Switch Scale Selection ‘The RANGE switch has three seales on 2 remov- able rings which correspond to the measurement capabilities of compatible power sensors, The range scales are 3W to 0.3 mW (+35 to -5 dBm), 100 mW to uW (+20t0-25 dBm) and 10 :Wto 0.3 (-20 to -65 dBm), Each seale listed indicates the maximum and minimum full sealemeterreadings. ‘To select the correct RANGE switch knob assem- bly scale (see Figure 2: a. Unserew the outer (black) knob by turning it, counterclockwise, Then, remove the outer knob. b, Remove the two scale rings, c. Determine which of the’ sealesis to be used d. Place the other scale ring on the knob assembly. e. Place the selected ring on the knob assembly with the selected scale out. £ Line up the tabs of the seale rings with the slot in the knob assembly. g. Hold the scale rings in place with your fingers. Thread the outer knob onto the knob assembly. Lightly tighten the knob. Scate BASE Figure 2-1. Changing Range Switch ScaleInstallation 2-6. Power Requirements ‘The Power Meter requires a power source with an output of 100, 120, 220, or 240 Vac +5%, ~10% sin- gle phase, 100 and 120 volts, 48 to 66 Hz and 260 to 440 Hz, 220 and 240 volts, 48 to 66 Hz. Power consumption is 20 V-A maximum. If this instrument is to be energized via an external autotransformer, makesure the autotransformer common terminal is connected to the earth terminal of the power source. 2-7. Line Voltage Selection BEFORE SWITCHING ON THIS IN- STRUMENT, make sure the instrument ig set to the voltage of the power source. Figure 2-2 provides instructions for line voltage and fuse selection. The line voltage selection card and proper fuse are factory installed for 120 Vac operation. Fuses may be ordered under HP part numbers 2110-0234, 0.1 (20V slow blow) for 100/120 Vac ‘operation and 2110-0040 0.062A (250V slow bow) for 220/240 Vae operation. 2-8. Power Cable In accordance with international safety stan- dards, this instrument is equipped with a three wire power cable. When connected to an appropri- ate ac power receptacle, this cable grounds the instrument cabinet. The type of power cable plug shipped with each instrument depends on the country of destination. Refer to Figure 2-3 for the part numbers of the power cable plugs available. BEFORE SWITCHING ON THIS IN- STRUMENT, the protective earth ter minals of this instrument must be con nected to the protective conductor of the (Mains) power cord. The Mains plug shall only be inserted in a socket outlet provided with a protective earth con- tact. The protective action must not be negated by the use of an extension cord (power cable) without a protective con- ductor (grounding). Model 435B Operating voltage is shown in module window, SELECTION OF OPERATING VOLTAGE 4, Open caver door, pul the FUSE PULL lever and rotate to Jat. Remove the tse 2, Remove te Line Voltage Selection Car, Position the card 50th ine voltage appears at tet cover, Push the card firm into the sit 43, Rotate the Fuse Pull ever to ts normal position, knsrt a use ofthe correct value Inthe holder. Close te cover door. WARNING To avoid the possibility of hazardous electri cal shock, do not operate this instrument at line voltages greater than 126.5 Vae with line frequencies greater than 66 Hz (leakage cur, renis at these line settings may exceed 3.5 mA) Figure 2-2. Line Voltage Selectien 2-9. Interconnections ‘The Power Meter and a power sensor are integral parts of this measurement system. Before mea- surements can be performed, the Power Meter and sensor must be connected together with the power sensor eable. (The cable is supplied with the Power Moter.) ‘The power sensor cable couples the de supply and sampling gate drive from the Power Meter to the power sensor and the 220 Hz acoutputsignal from the power sensor to the Power Meter. The maximum voltage which may be safely coupled to the Power Meter input from the power sensor is 18 mVrms. 2-10. Operating Environment ‘The operating environment should be within the following limitations:Model 4358 Installation, aon mua |] ofthat obtain rave sev or ebatsor ire riuoe ness wenscra Taete*swrstaozie | cate-Toreton is zareaoy OPERATION soor120v OPERATION PLUG: NEMA 5.15P CABLE: 8120-1978 PLUG*: NEMA 6:15 CABLE: HP #120-0698 220/240 OPERATION PLuG*: cEET-VII CABLE*: HP 8120-1689 PLUGS: CEEZ2.V1 CABLE*: HP 8120-18 220240 A mola orenaTion 22) orenaion SJ) SS) otuse: as 13634 60 GABLE: HP 8120-1351 "The number shown forthe cable isn HP part numer for complete eae inclu Figure 2-3. Power Cable HP Part Numbers Versus Mains Plugs Available Operating Environment (con's) Temperature y Oto 55°C Humidity 95% relative at 40°C Altitude. . <4570 metres (15 000 feet) 2-11. Bench Operation The instrument cabinet has plastic feet and a fold- away tilt stand for convenience in bench opera- tion. (The plastic feet are shaped to ensure self- aligning of the instruments when stacked.) The tilt stand raises the front of the instrument for easier viewing of the control panel. 2-12, Rack Mounting Instruments that are narrower than full rack width may be rack-mounted using Hewlett Packard adapter frames or combining cases. Adaptor Frames. Hewlett-Packard accessory adaptor frames are an economical means of rack mounting instruments that are narrower than full rack-width. A set of spacer clamps, supplied with each adaptor frame, permits instruments of dif- ferent dimensions to be combined and rack mount- ed asa unit. Accessory blank panels are available for filling unused spaces. Combining Cases. Model 1051A and 1052A Com bining Cases are metal enclosures that allow combinations of one-third and one-half rackewidth ingtruments to be assembled for use on a work- bench or for mounting in a rack of standard 19- inch spacing. Bach case includes a set of parti- tions for positioning and retaining instruments and a rack mounting kit. No tools are required for installing the partitions. For bench use the cases have the same convenient features as full rack- width instruments, (i.e, fold-away tilt stands and specially designed feet for easier instrument stack- ing). Accessories available for the combining cases include blank filler panels and snap.on full width control panel covers. 2-43. Battery Operation LN To operate the Power Meter on battery power, the battery must be installed and charged, the line power cable must he disconnected, and the LINE, switch must be ON. This task should be performed only by service trained persons who are aware of the potential shock hazard of working on an instrument with protective covers removed. Battery Inst To avoid hazardous electrical shock, the line (Mains) power cable should be dis- connected before attempting to install the battery.Installation Battery Operation (Cont'd) WARNINGS] (Cont'd) Do not short the battery terminals. This may result in overheating which can cause burns or increase risk of fire Do not incinerate or mutilate the bat tery, Tt might burst or release toxie ‘materials causing personal injury. The battery is installed in the Power Meter as follows (see Figure 2-4); a, Remove the top cover. b, Hold the battery above the Power Meter, parallel to printed circuit board Ad, The battery terminal lugs must face the circuit board. c. Loosen the lugs. Move the battery down into place and guide the lugs into the slots on the cir- cuit board. The battery should now rest on the aluminum deck. Model 4853 d. Place the battery clamp over the battery and secure it. The two prongs fit into slots on the rear panel and the 6.32 x 1/2inch pan head machine screw holds the forward end of the clamp in place. e, Tighten the battery terminal lugs by hand. Figure 2. installed. shows the Power Meter with battery Battery Charging. ‘The battery is being charged if the battery has been installed, theline power cable is connected to the available line power, and the LINE switch is ON. In thefully charged condition, (@4hour charge time), the battery will supply power for a minimum of 16 hours. 2-14, STORAGE AND SHIPMENT 2.15. Environment ‘The instrument should be stored in a clean, dry environment. The following environmental lim- itations apply to both storage and shipment: ‘Temperature . 55 to +75°C Humidity : <95%% relative at 40°C Altitude... +15 300 metres (50 000 feet) Figure 2-5. Power Meter with Battery InstalledModel 4358 2-16. Packaging Tagging for Service. If the instrument is being returned to Hewlett-Packard for service, please complete one of the blue repair tags located at the end of this manual and attach it to the instrument, Original Packaging. Containers and materials identical to those used in factory packaging are available through Hewlett-Packard offices. If the instrument is being returned to Hewlett-Packard for servicing, attach a tag indicating the type of service required, return address, model number and full serial number. Also mark the container FRAGILE to ensure careful handling. In any cor- respondence refer to the instrument by model number and full serial number. Other Packaging. The following general instruc- tions chould be used for re-packaging with com- mercially available materials: Installation a, Wrap the instrument in heavy paper or plas- tic. (If shipping to a Hewlett-Packard office or ser- vice center, attach a tag indicating the type of service required, return address, model number and full serial number. >. Use a strong shipping container. A double- wall carton made of 2.4 MPa (250 pound) test material is adequate. ¢._Usea layer of shock-absorbing material 70 to 100 mm (3 to 4 inches) thick around all sides of the instrument to provide firm cushioning and prevent movement inside the container. Protect the control panel with cardboard. d. Seal the shipping container securely , Mark the shipping container FRAGILE to ensure careful handling. f. In any correspondence, refer to the instru: ‘ment by model number and full serial number.® Model 435B Operation SECTION Il OPERATION 4, INTRODUCTION ‘This section provides complete operating instruc- tions for the Power Meter. The instructions consist of: panel features, operator's checks, operating instructions, power measurement accuracy and operator’s maintenance. 3-2. PANEL FEATURES Front and rear panel features of the Power Meter are described in Figures 3-1 and 3-2. These figures contain a detailed description of the controls, indi- cators and connectors. 3-3. OPERATOR'S CHECKS NOTE If the instrument does not operate prop- erly and ig being returned to Hewlett Packard for service, please complete one of the blue repair tags located at the end of this manual and attach it to the instrument. Upon receipt of the instrument, or to check the Power Meter for an indication of normal operation, follow the operational procedure shown in Figure 3-9, These procedures are designed to familiarize the operator with the Power Meter and to provide an understanding of the operating capabilities. 3-4. OPERATING INSTRUCTIONS General operating instructions are contained in Figure 3-4, The instructions will familiarize the operator with the basic practices used when oper- ating the Power Meter. Any interruption of the protective (grounding) conductor (inside or outside the instrument) or disconnecting the protective earth terminal is likely to ‘make this instrument dangerous. Inten tional interruption is prohibited. 3-5. POWER MEASUREMENT ACCURACY ‘A power measurement is never free from error or uncertainty, Any RF system has RF losses, mis- match losses, mismatch uncertainty, instrumen- tation uncertainty and calibration uncertainty, ‘Measurement errors as high as 50% are not only possible, they are highly likely unless the error sources are understood and, as much as possible, eliminated. 3-6, Sources of Error and Measurement Uncertainty RF Losses. Some of the RF power that enters the power sensor is not dissipated in the power sens- ingelements. This RF lossis caused by dissipation in the walls of waveguide power sensors, in the center conductor of coaxial power sensors, in the dielectric of capacitors, connections within the sensor and radiation losses. Mismatch. The result of mismatched impedances between the device under test and the power sen- sor is that some of the power fed to the sensor is, reflected before it is dissipated in the load. Mis- matches affect the measurement in two ways. First, the initial reflection is a simple loss and is called mismatch loss. Second, the power reflected from the sensor mismatch travels back up the transmission line until it reaches the source. ‘There, most of it is dissipated in the source impe- dance, but some of it is re-reflected by the source mismatch. The re-reflected power returns to the power sensor and adds to, or subtracts from, the incident power. For all practical purposes, the effect the re-reflected power has upon the power measurements unpredictable. This effectis called mismatch uncertainty. Instrumentation Uncertainty. Instrumentation un- certainty describes the ability of the metering cir- cuits to accurately measure the de output from the power sensor's power sensing device. In the Power Meter, this error is less than +1%.' It is important to realize, however, that a 1% meter does not auto- matically give 1% overall measurement accuracy. Power Reference Uncertainty. The uncertainty of the output level of the power reference oscillators 40.7%. This references normally used to calibrate thesystem andis, therefore, apart ofthesystem's total measurement uncertainty. evo ftrarun 008 + specifieston in Section when ange B1Operation Cal Factor Switch Resolution Error. The resolution of the CAL FACTOR switch contributes a signifi: cant ertor to the total measurement because the switch has 1% steps. The maximum error possible in each position is 40.5%. 3-7. Corrections for Error Calibration Factor and Etfective Efficiency. The two correction factors basic to power meters are cali- bration factor and effective efficiency. Effective efficiency is the correction factor for RF losses within the power sensor. Calibration factor takes into account the effective efficiency and mismatch losses. Calibration factor is expressed as a percentage with 100% meaning the power sensor has no losses. Normally the calibration factor will be 100% at 50 MHz, the operating frequency of the internal reference oscillator, ‘The power sensors used with the Power Meter have individually calibrated calibration factor curves placed on their covers. To correct for RF and mismatch losses, simply find the power sen- sor’s calibration factor at the measurement fre- quency from the curve or the table that is supplied. with the power sensor, and set the CAL FACTOR, switch to this value. The CAL FACTOR switch resolution error of +0.5% may be reduced by one of the following methods: 1) Set the CAL FACTOR switch to the nearest positions above and below the correction factor given on the table. Interpolating between the power levels measured provides the corrected power level. 2) Leave the CAL FACTOR switch on 100% after calibration. Then, make the measurement and record the reading. Use the reflection coeffi- cient, magnitude and phase angle, if such a table is supplied with the power sensor, to calculate the corrected power level. 3-8, Calculating Worst Case Uncertainty Worst case uncertainty is the sum of the specified uncertainties and mismatch uncertainty. Uncer- tainty calculatigh is outlined in the following two subsections and examples are worked out in Fig- ures 3-5 and 36. For a more complete explanation of measurement uncertainty refer to HP applica: tion note AN-64-1 “Fundamentals of RF and Mi- crowave Power Measurement” a2 Model 435B Specified Uncertainties. The specified uncertain- ties which account for part of the total power mea: surement uncertainty are: a. Instrumentation 1%! or +0.05 dB. b. Power reference +0.7% or £0.03 dB. c. CAL FACTOR switch resolution, 0 to (depending on Cal Factor). a, Zoro set, 0.5% of full scale of lowest range which is 15 nW. e. Zero Carryover, #0.5%. £ Noise and Drift, depends on the range and type of sensor. g. Calibration factor uncertainty, which depends on sensor type, is listed in the sensor manual. Figure 3.5 gives an example of specified uncer- tainty calculation. Calculating Mismatch Uncertainty. Mismatch un- certainty is the result of the source mismatch interacting with the power sensor mismatch. The magnitude of uncertainty is related to the magni- tudes of the source and power sensor reflection coefficients, which can be calculated from SWR. Figure 3-6 shows how the calculations are made and Figure 37 illustrates mismatch uncertainty and total calculated uncertainty for two cases. In the first case, the power sensor's SWR= 1.5, andin the second case, the power sensor's SWR = 1.25.In both cases the source has an SWR of 2.0. The example shows the effect on power measurement accuracy a poorly matched power sensor will have as compared to one with low mismatch. ‘A faster, easier way to find mismatch uncertainty is to use the HP Mismatch Error (uncertainty) Limits/Reflectometer Calculator. The calculator may be obtained, on request, from your nearest Hewlett-Packard office by using HP part number 59520948, ‘The method of calculating measurement uncer- tainty from the uncertainty in dB is shown by ‘gure 3-8, This method would be used when the initial uncertainty calculations were made with the Mismatch Error/Reflectometer Calculator. ‘Refer io Ingtrament accuracy specification in Section] when using theModel 4358 3-9. OPERATOR'S MAINTENANCE ‘The only maintenance responsibilities the opera- tor should normally perform are primary power fuse replacement, LINE switch lamp replacement and rechargeable battery replacement. Battery replacement is the only operation that requires tools. A Pozidriv screwdriver is needed to remove the battery clamp. 3-10. Fuses ‘The primary power fuse is found within the A6 Power Module Assembly on the Power Meter's rear panel. For instructions on how to change the fuse, refer to the paragraph entitled Line Voltage Selection in Seetion II. Make sure that only fuses with the required rated current and of the speci fied type (slow blow, timedelay,ete.)are used for replacement. The use of re paired fuses and the short-cireuiting of fuse-holders must be avoided. 3-11. Lamp Replacement ‘The lamp is contained in a plastic lens which dou- bles for a pushbutton on the LINE switch. When Operation the Power Meter LINE switch is ON and is being operated by the available line power, the lamp should be illuminated. If the lamp is defective, remove the lens by pulling it straight out, Order lamp (3131-0434) CD6 and replace the old pushbutton-lamp assembly with the new one. To replace the assembly, align the pins with the notch in the receptacle and push straight in. 3-12. Battery Replacement If the meter indicates that the battery is dis- charged by a full downscale reading, and after charging the battery still will only power the Power Meter for a short period of time, the battery is probably defective, The replacement battery, BT1 (HP part number 1420-0096), may be ordered through the nearest Hewlett-Packard office. Refer to Battery Installation in Section II. This task should be performed only by service trained persons who are aware ofthe potential shock hazard of working on an instrument with protective covers removed.Operation Model 4358 @ Meter. Normaily indicates average RF power in aBmor Watts. During battery operation the meter continuously indicates battery eondition. A nor malreading indicates the battery is charged: full down-scale reading indicates the battery is dis charged or is defective © Meter Zer0. Mechanical adjustment used tozero the meter when the LINE switch is OFF. | @ LINE switen. Connecis line or battery power to the Powor Meter circuits when the LINE switch is ON. During battery operation, the lamp contained | within the LINE awitch will not be illuminated ‘when the INSTRUMENT is ON. © AANGE switch, Selects desired power range; keyed to meter full-scale deflection; has three removable sealee which are changed to match the range of the power sensor. FRONT PANEL FEATURES (@ POWER REF OUTPUT. RF output of 1.00 mW 40.70% into 600 at 50 MElz from on internal reference oeeillator, Available for system calibration. QCAL ADI. Screwdriver adjustment for calibrating any power sensor and Power Meter as asystem, to a known standard, | © iu canner. ropa fom the power sensor via the power sensor eable CALFACTOR Switch. Changes the gain ofthe Power Meier amplifier cireuits to compensate for mis rnatch losses and effective effcieney of the power sensor. ZERO Switch. Te ZERO switeh activates a feed back circuit, which automatically zeros the meter pointer, and a rear panel RF blanking signal Figure 3-1. Front Panel Controls, Connectors and Indicators a4¢ Model 436B Operation tf REAR PANEL FEATURES @ POWER SENSOR INPUT. Option 002.and 003 havea ear pane] input connector wired in parallel with the front panel input connector. © Power Module Assembly. @ Window. saiety interiock; fuse cannot be removed while power cable is connected to Power Meter. FUSE PULL Handle, Mechanical interlock to guar. antee fuse has been removed before Line Voltage | Selection Card ean be removed, @ Fuse. Rover to Section I for values. | © Line Voltage Selection Card. Matches transformer | primary 1 available ine voltage. @ Receptacle. For power cable connection to avail- able line voltage. © POWER AEF OUTPUT. Takes the place of the front panel POWER REF OUTPUT connector (Option 003 only). © FECORDER OUTPUT. Provides a linear output with, respect to the input power. +1.00 Vée corresponds to meter full-scale, The minimum load which may be coupled to the output is 1 Ma. @ AF BLANKING OUTPUT. Contact closure to ground when ZERO switch is pressed, May be used to remove RF input signal during automatic zeroing operation. @ POWER AEF Switch. Opens or closes the circuit from the power supply to the power reference oscil- lator, Reduces current drain during battery opera tion when OFF. Figure 3-2. Rear Panel Contras, Connectors. and IndicatorsOperation Model 4353 OPERATOR'S CHECKS 1. BEFORE SWITCHING ON THIS INSTRUMENT, check that the power transformer primary is matched to the available line voltage, the correct fuse is installed and the safety precautions are taken, See Power Requirements, Line Voltage Selection, Power Cables and associated warnings and cautions in section Il. BEFORE CONNECTING LINE POWER TO THIS INSTRUMENT, ensure that all devices connected to this instrument are connected to the protective (earth) ground, BEFORE SWITCHING ON THIS INSTRUMENT, en- ure that the line power (Mains) plug is connected to @ three-conductor line power outlet that has a protective (earth) ground. (Grounding one conductor of a two conduetor outlet is not sufficient.) Do not twist the body of the power sensor when connect ingordisconnecting it. This cancause majordamageto the power sensor. 2, Set the meter indication to zero with the mechanical meter zero control. Back the control off slightly, 3, Connect the power sensor to the Power Meter with the power sensor cable, 4. Connectthe power cable to the power outlet and power module receptacles. Setthe LINE switeh to ON; the lamp within the switch lens should be illuminated. 5. Change the Power Meter’s RANGE switch scale so it corresponds to the range of the power sensor. Refer to the paragraph entitled Range Switch Scale Selection in Section {1 6 Set the Power Meter Controls ax follows RANGE switeh position fully cow CAL FACTOR switch ......2-.+++-100% POWER REF switch ORF Press the ZERO switch and verify that the meter pointer moves to zero (0) and the RF BLANK: ING OUTPUT is shorted to ground. 5, Set the RANGE switch to the position indicated in the following table. Then, connect the power sensor (and adapter or attenuator as required) to the POWER REF OUTPUT and set the rear pane] POWER REF ewitch to (ON). Verify that the meter reads approximately the same as indicated in the table. Figure 3-3. Operator's Checks (1 of 2) 36Model 435B Operation OPERATOR'S CHECKS RANGE Switeh| Meter Pee ae Piten | indcation 4481B and 84928 (remove attenuator) aw aw | S161, stb2a, st, 2H 3mW | imi 8485A (HP 1250-1250 Adapter required) amw | imaW 8483A (HP 1250-0597 Mechanical Adapter required) amw | osemw 84844 (HP 11708A Reference Attenuator rrequired) 3 uw 1 aW 9. Step the CAL FACTOR switch through its range noting a small inerease in meter reading with each successive step. Resot the CAL FACTOR switch to 1008, 10. Set the RANGE switch to the position indicated in the table below. Then, adjust the CAL ADJ control for a full-scale moter reading for 500 power sensors and a 96% of full scale meter reading for 750 power sensors. Power Sensor ANGE Switch Patan ‘4818 and 64828 remove attenuator) Ww | etsia, saa, eet, seaatt Timi 84854 (HD 1250-1250 Adapter required Taw ESA (HP 12500507 Mechanical Adapter eguired) Tm BAA (HP 11708A Reference Attenuator required) Law 11. Cheek at the rear panel RECORDER OUTPUT jack for an output of ~ 1 Vde. 12, To check operation using battery power, disconnect the power cable from the rear panel power module receptacle and set the LINE switch to ON (the lamp within the switch lens will not be illuminated). When a power measurement is made, a normal upscale reading indicates normal operation; a full down-scale reading indicates the battery is discharged. Figure 3-3. Operator's Checks (2 of 2)Operation ‘Model 4358 OPERATING INSTRUCTIONS BEFORE SWITCHING ON THIS INSTRUMENT, check that the power transformer primary is. matched to the available line voltage, the correct fuse is installed and safety precautions are taken. See Power Requirement, Line Voltage Selection, Power Cables and associated warnings and cautions in Section TL BEFORE CONNECTING LINE POWER 10 THE INSTRUMENT, ensure that all devices connected to this instrument are connected to the provective (earth) ground. BEFORE SWITCHING ON THIS INSTRUMENT, en- sure that the line power (Mains) plug is connected to a three.conductor line power outlet that has a protective (earth) ground. (Grounding one conductor of « two- conductor outlet is noc sufficient.) Donot twist the body of the power sensor when connect- ing or disconnecting it. This can cause major damageto the sensor. Set the meter indication to zero with the mechanical meter zero control. Back the control off slightly, Connect the power sensor to the Power Meter with the power sensor cable. Connect the power eable to the power outlet and power module receptacles, Set theLINE switch to ON; the lamp within the switeh lens should be lit, Change the Power Meter’s RANGE switch scale so it corresponds to the range of the power sensor. Refer to the paragraph entitled Range Switch Scale Selection in Section IL. Set the Power Meter switches as follows: RANGE position. .....6s...10.2+. fully cow CAL FACTOR. ieee 100% POWER REF... OFF Press the ZERO switch, allow 5 seconds for the zeroing operation to take place, and release the switch, Set the RANGE switch to the position indicated in the following table. Then, connect the power sensor (and adapter or attenuator as required) to the POWER REF OUTPUT and set the rear panel POWER REF switch to (ON). For 502 power sensors, adjust the CAL ADJ control for a full-scale reading; the meter pointer should be aligmed with the CAL mark (full-scalereading) on the meter face. For 750 power sensors, adjust the CAL ADJ control for 2 96% of full scale reading; the meter pointer should be aligned with the 0.96 mark on the meter face. 38 Figure 3-4. Operating Instructions (1 of 2)Model 435B Operation or OPERATING INSTRUCTIONS Power Soar fANGE Swish Palon 4S1B and 84828 romove attenuator) we | SABLA, BASRA, SAH, S480 TW 185A (HP 1260-1250 Adaptor required) mW | 483A (HP 1250-0597 Mechanical Adapter required) S44A (HP 11708A Reference Attenuator required) | 1 AW | im | 9 Disconnect the power sensor from the POWER REF OUTPUT and set the POWER REF switeh to OFF. 10. Locate the calibration curve on the power sensor cover, Find the CAL FACTOR for the measure. ment frequency; set the CAL FACTOR switch accordingly. 11, Set the RANGE switch such that full seale is greater than the power level to be measured. See Operating Precautions in the power sensor Operat ing and Service Manuals for maximum power levels which may be safely coupled to this systera. Levels which exceed the limits may damage the power sensor, Power Meter, or both. 12, Connect the power sensor to the RF source. Read the power lavel in dBm or Watts on the panel NOTE When the battery is being used as the power supply for the Power Meter, an automatic test circuit continually monitors battery condition. When the battery voltage is ‘above a predetermined level, the meter indicates the correct power level. When the voltage drops below the threshold level, the meter reading is full downscale. ) Figure 3-4, Operating Instructions (2 of 2) 39Operation Model 435E SPECIFIED UNCERTAINTY CALCULATION Conditions: Range —1 mW Meter Reading ~ 0.7 mW Sensor — 841A, Frequeney — 1 GHz CAL FACTOR — 99.5% Instrumentation Uncertainty Power Reference Uncertainty CAL FACTOR Switch Resolution Uncertainty Zero Set Uncertainty Zero Carryover Uncertainty Noise Drift Cal Factor Uncertainty £0.06 4B +003 4B £0.02 dB ++0.00009 4B £0.03 4B 0.00025 4B. 70.0008 dB 20.12.48 40,000015 mW 40,019 mW 0825 mW Total Specified Uncertainties ~ 10.015 mW = 2985 9 sa. O55 say =10 225 = 205 8 NOTE: FS =% of full seale R = %ofreading ire 3-5. Specified Uncertainties 310Model 4358 Operation, CALCULATING MEASUREMENT UNCERTAINTY, 1. Calculate the reflection coefficient from the given SWR. PU, = {1+ [(0.2(0.833)] }? = {us 0.067}? = {uoer}* and {0.933} = 1.188 and 0.871 = 0111 Pu fh (ones)]* sWR-1 6° SWRI Power Sensor #1 Power Sensor #2, Power Source SWR=15 SWR= 1.25 SWR = 2.0 is 125-1 &* T5ei 1.2541 = 0.388 2. Calculate the relative power and percentage power mismatch uncertainties from the reflection coefficients. An initial reference level of 1 is assumed. Relative Power Uncertainty {2 = 0.2111)(0.299)) }* {1+ 0.087}? {1.037}? and {0.963 }* 1.075 and 0.927 Percentage Power Uncertainty %PU = (PU-1) 100% RPU, = (1.1381) 100% and (0.8711) 100% = (0.188) 100% and (0.129) 100% = 13.8% and 12.9% %PU; = (1.0751) 100% and (0.9271) 100% = (0.075) 100% and (0.073) 100% = 15% and -1.8% Figure 3-6. Caleulating Measurement Uncertainties (1 of 2)Operation Model 4358 3. Calculate the Measurement Uncertainty in dB =) | # MU, Mu, CALCULATING MEASUREMENT UNCERTAINTY ws «8 [ona 10 [tog )] 10 (0.056) +0.56 dB 10 [ioe (=2)] 10 [0.031] 40.31 4B and and and and and and ost 10 [10s (*2)] 10 [0.060] 0.60 dB 1 1 [oe (22) 10 [-0.083] 0.83 dB 342 Figure 3-6. Calculating Measurement Uncertainties (2 of 2)Model 4358 Operation INDICATED POWER VERSUS RANGE OF ACTUAL POWER (Values from examples on Figures §-5 and 3-6.) INDICATED POWER “TOTAL SPECIFIED WORST CASE UNCERTAINTY UNCERTAINTIES (SPECIFIED & MISMATCH) ' t 0.84 mW (0.73 48h t EXAMPLE 1 i SENSOR SWR = 1.5 ' SOURCE SHR = 2.0 ACTUAL POWER i |eaa% [+199% ANYWHERE IN { SHADED AREA 0.74 mt (-1,28 dBm) 10.65 ad (1.81 dBm) O67 mW (2.4 dBm) EXAMPLE? AUPE ag 6.8 iv (0.98 8m Savage SHR=20 ACTUAL POMER suse erase ANvuniene Iv 0,74 mW |-1.29 dBm) cotati 7 / Vein! J / 047 i (1.58 Bm) LLL LL 0.68 ni (1.81 dBm) ' 0.6 mW (=2.1 dBm) Figure 3-7. Worst Case Effects of Specified and Mismatch Uncertainties5B Operation Model 43 CALCULATING MEASUREMENT UNCERTAINTY, 1. For this example the known values are: source SWR, 2.2 and power sensor SWR, 1.1 From the Mismatch Error Calculator the mismatch uncertainty is found to be +0.24,—0.25 dB, certainty is +0.50,~0.51 dB. Add the specified uncertainties from Figure 3-5, (« 26 dB). Our total measurement un- 3. Caleulate the relative measurement uncertainty from the following formula: dB aB 10 ey 10 tox( $4) Po, Py (2) 4. Calculate the percontage Measurement Uncertainty. aU (Py —Po) 100 = (1.1221) 100 = 412.2% 051 ven (6 ) 0.389 (0.889 ~ 1) 100 11% Figure 3-8. Calculating Measurement Uncertainty (Uncertainty in dB Known) S14