Страница 1: ...tion as smooth as possible for you However as a result of this transition the products and related documentation contained in this shipment may be labeledwith either the Hewlett Packardname and logo the Agilent Technologies name and logo or a combination of both Information in this package may refer to Hewlett Packard HP but applies to your Agilent Technologies product Hewlett Packardand Agilent b...
Страница 2: ... to INSTRUMENTSCOVERED BY THISMANUAL in Section 1 S i x t hEdition T h i s material may be reproduced by or for the U S Government pursuant to the Copyright License un der the clause at DFARS 52 227 7013 AF R 1988 Copyright HEWLETT PACKARD COMPANY 1989 EAST24001 MISSION AVENUE LIBERTY LAKE WASHINGTON U S A 99019 9599 Operationand CalibrationManualHPPart08901 90113 OtherDocumentsAvailable ServiceMa...
Страница 3: ...1 Regulatory Information Updated March 1999 1 ...
Страница 4: ...source to the product input wiring terminals power cord or supplied power cord set SAFETY SYMBOLS AIndicatesinstrument damage can occur if indicated operatinglimits are exceeded A Indicateshazardous voltages Indicates earth ground terminal WARNING A WARNING note denotesa hazard It calls attentionto a procedure practice or the like which if not correctlyperformedor adheredto could result in persona...
Страница 5: ... serviceableparts in this product Refer servicingto qualified personnel To prevent electrical shock do not remove covers Servicinginstructions are for use by qualifiedpersonnel only To avoid electricalshock do not perform any servicingunless you are qualified to do so The opening of covers or removal of parts is likely to expose dangerousvoltages Disconnectthe product from all voltage sources whil...
Страница 6: ...duct must not be restricted The ambient temperature outsidethe cabinet must be less than the maximum operatingtemperature of the product by 4 C for every 100 watts dissipated in the cabinet If the total power dissipated in the cabinet is greater than 800 watts then forced convection must be used Product Markings CE the CE mark is a registered trademark of the European Community A CE mark accompani...
Страница 7: ...that its software and firmware designated by HP for use with an instrument will execute its programming instructions when properly installed on that instrument HP does not warrant that the operation of the instrument or software or firmware will be uninterrupted or error free LIMITATION OF WARRANTY The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance ...
Страница 8: ...result in dam age to or destruction of part or all of the product Do not proceed beyond a CAUTION sign until the indi cated conditions are fully understood and met Any interruption of the protective ground ing conductor inside or outside the instru ment or disconnecting the protective earth terminal will cause a potential shock hazard that could result inpersonal injury Ground ing one conductor of...
Страница 9: ...e generated in numerous ways such as simple con tact separation of materials and normal motions of persons working with static sensitive devices When handling or servicing equipment containing static sensitive devices adequateprecautions must be taken toprevent device darn age or destruction Only those who are thoroughly familiar with industry accepted techniques for handling static sensitive devi...
Страница 10: ...e HP IB Address 1 3 Additional Equipment Information 1 3 Options 1 3 Accessories Supplied 1 4 Electrical Equipment Available 1 4 Mechanical Equipment Available 1 5 Description ofthe Modulation Analyzer 1 6 RF Power Measurements 1 6 RF Fkequency Measurements 1 7 Modulation Measurements 1 7 Additional Features 1 7 Specialhctions 1 8 Extending Measurement Range 1 8 Programmability 1 8 1 8 RF Circuitr...
Страница 11: ...perating Instructions Section 3 2 Other Sourcesof Operating Information 3 2 Operating Characteristics of the Measuring Receiver 3 2 Operator sInformation 3 2 Fbes 3 2 Time Base 10 MHz Input and Time Base 10 MHz Output 3 3 Description 3 3 Turn On Procedure 3 3 Instrument Features 3 4 Front Panel Features 3 6 Rear Panel Features 3 9 Remote Operation VIA the Hewlett Packard Interface Bus HP IB 3 13 I...
Страница 12: ...s 3 34 Code Execution in the Modulation Analyzer 3 34 Basic bctional Checks of the Modulation Analyzer 3 47 Description 3 47 Equipment 3 47 Procedure 3 47 Basic bctional Checks of the Hewlett Packard Interface Bus HP IB 3 56 Description 3 56 Initial Setup 3 57 Equipment 3 57 Procedures 3 57 Detailed Operating Instructions 3 67 Introduction to This Section 3 67 Section Organization 3 67 How to Find...
Страница 13: ...ment 1 Power Supply 5 5 Adjustment 2 Internal Reference 5 6 Adjustment 3 RF Level Detector Offset 5 7 Adjustment 4 SamplerEfficiency and Offset 5 8 Adjustment 5 LO Doubler Output Power and Balance 5 10 Adjustment 6 Voltmeter Offset and Sensitivity 5 12 Adjustment 7 15 kHz and 20 kHz Low Pass Filter Gain 5 14 Adjustment 8 ALC Reference 5 15 Adjustment 9 FM Calibrator 5 16 Adjustment 10 FM Sensitivi...
Страница 14: ...General Information Model 8901B MODEL 8901B LINE POWER CABLE Figure 1 1 HP 8901B Modulation Analyzer and Supplied Accessories 1 0 ...
Страница 15: ...ented by this manual and covers instrument description options accessories specificationsand other basic information This section also contains instrument theory of operation on a simplified block diagram level Section 2 Installation provides information about initial inspection preparation for use including address selection for remote operation and storage and shipment Section 3 Operation provid...
Страница 16: ...s with equivalent minimum specifications may be substituted Table 1 2 also includes some alternate equipment listings Table 1 3 lists a number of accessories required in additionto those containedin the Service Accessory Kit HP 08901 60287 1 5 INSTRUMENTS COVERED BY THIS MANUAL Options Electricaloptions 001 002 003 004 series030 and various mechanicaloptions are documented in these manuals The dif...
Страница 17: ...re located within the ModulationAnalyzer The switchesrepresent a five bitbinary number This number represents the talk and listen address characters which the controllermust generate In addition two more switchesallow the ModulationAnalyzer to be set to talk only or to listen only A table in Section2 shows all HP IBtalk and listen addresses Refer to HP IBAddress Selection in Section2 of this Opera...
Страница 18: ...ped automatically with every Modulation Analyzer Line Power Cable The line power cable may be supplied in several plug configurations depending on the destination of the original shipment Refer to Power Cables in Section 2 of this Operating Information manual Fuses Fbes with a 2 5A rating for 115 Vac HP 2110 0083 and a 1 5A rating for 230 Vac HP 2110 0043 are supplied One fuse is factory installed...
Страница 19: ...tability internal reference oscillator Order HP part number 08901 60281 Rear Panel Local Oscillator Connections Retrofit Kit Option 003 This kit contains all the necessary components and full instructions for installation of rear panel local oscillator connections Order HP part number 08901 60280 These connections are already included in all Option 030 Series instruments Conversion to 400 Hz Line ...
Страница 20: ... display shows measurement results with excellent resolution and is easy to read All Modulation Analyzer operations can be controlled and all measurement results can be transferred via the Hewlett Packard Interface Bus HP IB HP IB is Hewlett Packard s implementation of IEEE Standard 488 and ANSI Standard MC1 l RF Power Measurements The Modulation Analyzer delivers the accuracy and resolution of a ...
Страница 21: ...on so that this type of modulatingwaveform can also be accurately measured De Emphasis Networks The Modulation Analyzer contains four de emphasisnetworks that can be used in addition to the audio filters These are the ones commonly used in FM communications 25 50 75 and 750 ps When selected the de emphasis networks always affect the demodulated output You can select whether the de emphasis network...
Страница 22: ... accomplishedwhen an external LO and mixer are includedin the measurement path This system then functions as a single instrument making microwave modulation frequency power and level measurements You control operation from the Modulation Analyzer s front panel When the external LO frequency must be changed the Modulation Analyzer requests an external controllerto make the change A separate non vol...
Страница 23: ...ily damaged by sudden large overloads Refer to Table 1 1 under RF Power Supplemental Characteristics RF Power Ranges ofHP 8901B Modulation Analyzer with HP 11722A Sensor Module for information on maximum operating lemls When the RF Peak Detector senses that the input signal level exceeds lW it opens the Overpower Relay This is done without intervention of the Controller The output from the RF Peak...
Страница 24: ... AM tNPUl e OR 2 5 Ynz LP FILTER OEYOOULAlOR IF OVERPOWER RF HP INPUT CI AM C I CI L 1 OR I I CHANNEL IF RYS FILTERS OElECTOR AUOlO AV6 OElEClOR AUDIO PEAK DETECTOR OlSlORTlON AUDIO RYS P O I I DP O I I iopiiow 030 SERIES ONLY POWER AUOIO COUNlER I F PEAK OElECTOR II I POWER REFERENCE 2 OSCILLATOR 1 ...
Страница 25: ...edasthe IF frequencyis detunedby a pre determined offset Audio Circuitry The modulation on the IF is demodulatedby either the AM or the FM Demodulator Phase modulation is recovered by integrating the demodulated FM in the Audio Filters and Gain Control circuitry The demodulated signal is amplified and filtered in the Audio Filters and Gain Control circuitry The filters are selected from the front ...
Страница 26: ...ich conveysthe information A signalwithout modulation is said to be a continuous wave CW signal CW signalscontain two information carryingparameters amplitude and frequency These two parameters however are static time invariant Consequently the information conveyed by them is scant you know only that a signal is present at a certain frequency When one or both of these parameters is altered as a fu...
Страница 27: ...calledT the modulation index rn usuallyexpressed in is defined as P T m x 100 In the example of Figure 1 3 P 1 5and T 0 5 therefore 1 5 0 5 m x 100 50 1 5 0 5 Figure 1 4 shows AM signals with modulation indexes varying from 0 to 100 a 0 AM CW b 30 AM c 70 AM d 100 AM Figure 1 4 AM for Various Depths 1 13 ...
Страница 28: ...ircuit The signal is then demodulated and the amplitude of the recovered baseband signal is measured with a peak detector The output of the detector is r which is in effect multiplied by the constant 1OO A and displayed as the 9 AM b AMPLITUDE MODULATED CARRIER I Figure 1 5 AM with an Asymmetrical Baseband Signal The range of modulation indexes for AM measurementsby the Modulation Analyzer is esse...
Страница 29: ... the demodulated FM This relationship is most easily visualized by some examples Look at Figure 1 7 The first baseband signal shown is a square wave The three waveforms under it are the result of applying this signal to an FM QM and AM modulator respectively The AM waveform is included only for reference It is assumed that the phase modulator doesn t produce AM only QM The FM waveform is as expect...
Страница 30: ...s highest when the slope of the baseband signal is steepest in a positive direction This occurs at the positive going zero crossing Similarly the frequency is lowest when the slope is most negative If in the last example the rate but not the amplitude of the baseband signal is increased the highest and lowest frequenciesof the signal from the frequency modulator stay the same they just occur more ...
Страница 31: ...l CW signal also contains a small amount of residual AM FM and ckM The residual modulation is generated by such things as line hum noise and microphonics The residual AM and FM specificationsquantify the residual modulation internal to the Modulation Analyzer Residual modulation affects the modulation readings in a manner which depends on the detector used the nature of the residuals and the signa...
Страница 32: ...ore applying it to the modulator This is called pre emphasis The boost is a simple 6 dB per octave with the 3 dB comer specified by a time constank for example 75 ps which corresponds to a 3 dB comer of 2 12 kHz for commercial broadcast FM If desired the demodulated FM can be de emphasized to equalize the signal at the modulation output and at the display 1 18 ...
Страница 33: ...Y using Recorder Outputfi INTERNAL NON VOLATILE CAL FACTOR TABLES user modifiable using special functions MAXIMUM NUMBER OF CAL FACTORIFREQUENCY ENTRIES Table 1 Primary 16 pairs plus Reference CaI Factor Table 2 Frequency Offset 22 pairs plus Reference CaJ Factor MAXIMUM ALLOWED FREQUENCY ENTRY FREQUENCY ENTRY RESOLUTION 50 kHz CAL FACTOR RANGE 40 to 120 RF RANGE TO RANGE CHANGE ERROR INPUT SWR c1...
Страница 34: ...eak measurements only AM accuracy may be affected b distortion generated by the Analyzer In the worst case this distortion can decrease accuracy by 0 1 of reading for each 0 1 of distortion 6 Flatness is the variation in indicated AM depth for constant depth on input signal For optimum flatness cables should be terminated trith their choracteris tic impedonce detector 1 20 0 1 0 01 I 0 01 V percen...
Страница 35: ...0 Hz to 100 kHz DETECTORS peak peak peak 2 peak hold nith degraded performance average rrns sinewave calibrated rrns Modulation Reference AM CALIBRATOR DEPTH AND ACCURACY 33 33 depth nominal internally calibrated to an accuracy of 0 1O 0 34 kHzpeak deviation nominal internally calibrated to an accuracy of 0 1 FM CALIBRATOR DEVIATION AND ACCURACY rev 19DEC88 Supplemental Characteristics CARRIER FRE...
Страница 36: ...emental Characteristics MEASUREMENT 3 dB BANDWIDTH 20 Hz to 50 kHz DETECTION True rrns MEASUREMENT RATE I rradinp s AUDIO INPC T IMPEDA VCE 100 k nominal Audio RMS Level FREQUENCY RANGE 50 Hz to 40 kHz VOLTAGE RANGE 100 mV to 3V ACCURACY 2 4 0 of reading Supplemental Characteristics FULL RANGE DISPLAY 3000V 4 000v AC CONVERTER true rms responding for signals with MEASUREMENT RATE 2 reading AUDIO I...
Страница 37: ...m D HP SYSTEM I1 MODULE SIZE 177 0 H X 1 MLY X 497 8 D 7 5 X 16 8 X 21 7 HP 8901B Rear Panel Inputs Outputs Supplemental Characteristics FM OUTPUT 10 kR impedance 9V to 6Vinto an open circuit 6V MHz dc coupled 16kHz bandwidth one pole AM OUTPUT 10 kR impedance 4V to OV into an open circuit 8 mV dc coupled 16kHz bandwidth one pole RECORDER OUTPUT DC voltage proportional to the measured results 1 kR...
Страница 38: ...70 80 90 6 4 2 0 2 4 6 8 10 12 14 16 18 20 Relative Frequency kHz 30 0 kHzFilterShape 12 8 4 0 4 8 12 16 20 24 28 32 36 40 Relative Frequency kHz Noise Bandwidth Correction Accuracy stored in non volatile memory 20 2 dB Supplemental Characteristics ADJACENTIALTERNATE CHANNEL FILTERS 6 dB Filter Bandwidth 8 5 kHz 12 5 kHz adjacent channel filter 16 0 kHz 25 kHz adjacent channel filter 30 0 kHz 30 k...
Страница 39: ...ndwidth AM Depth 5 to 99 AM Distortion 66 dB at 30 AM at 20 Hz to 100kHz rates 60 dB at 4 5 AM at 20 Hz to 100kHz rates iO 1 from 50 Hz to 50 kHz f0 25 from 20 Hz to 100kHz AM Flatness incidental QM 0 008 rad peak at 12 5 MHz with 50 AM at a 1 ResidualAM 0 01 rms in a 50 Hz to 3 kHz bandwidth AM Linearity kHz rate in a 50 Hz to 3kHz bandwidth fO lYOat 95 AM 3 0 2 at 4 9 AM Frequency 30 MHz SWR Max...
Страница 40: ...IBcompatibilityas defined by IEEE Std 488 and the identical ANSI Std MC1 l SH1 AH1 T2 TEO L2 LEO SRO PPO DCO DTO and Cl 2 3 4 5 DC Range 0 to 50V DC Accuracy f0 01 at 1V AC Range 0 to lOOV AC Accuracy f0 01YOat 2V and 2 kHz Ohms Range 0 to 1 Mfl Ohms Accuracy f l Divider Ratio 1O l Input Impedance 1 MR Input Capacitance lo pF No substitution is recommended Accuracy k O l ppm recommended Bandwidth ...
Страница 41: ...T HP 11722A HP 08901 60287 Thermistor Mount Power Reference Power Supply Range Calibrator RF Spectrum Analyzer Sensor Module Service Accessory Kit Signal Generator C Operator s Suggested Model Critical Specifications Power Range 1 mW Transfer Accuracy input to output 0 2 SWR 1 0550 MHz Accuracy f 0 5 at 50 MHz HP 432A HP 478A H75 or HP 478A H76 Frequency Range 0 5 to 1100 MHz Output Level 19 dBm m...
Страница 42: ...0R Directivity 40 dB Connectors Type N I I I C Operator s Checks P Performance Tests A Adjustments T Troubleshooting Adapter Type N Male to BNC Female connectors Capacitor 620 pF IC Extender Clip 16 Pin Resistor 90901O O 1 4W Resistor 121001YO1 4W Resistor 215001 1 4W Resistor 464001O O 1 4W Tee Coaxial BNC one Male and two Female connectors 50nLoad Male BNC coaxial HP 1250 0067 HP 0160 3536 HP 14...
Страница 43: ...ve been checked for completeness and the instrument has been checked mechanically and electrically Procedures for checking electrical performance are given in Section 4 If the contents are incomplete if there is mechanical damage or defect or if the instrument does not pass the electrical performance test notify the nearest Hewlett Packardoffice If the shipping container is damaged or the cushioni...
Страница 44: ...the earthed pole of thepower source Power Cables IWARN NGI BEFORE CONNECTING THIS INSTRUMENT the protective earth terminals of this instrument must be connected 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 contact Theprotective action must not be negated by the use of an extension cord power cable with...
Страница 45: ... 4 6 Cable HP Part Number STR 90 177 Gray STR STR NEMA6 15P 90 Black United States Cable For Use Cable Plug Description 3 4 8120 1351 8120 1703 90 STR 79 Gray Denmark 9oo 900 0 4 4 8120 1369 8120 0696 8120 1689 8120 1692 8120 1378 8120 1521 8120 1751 STR STR 8120 4753 8120 4754 8120 2104 8120 2296 8120 3997 8120 0698 8120 2956 8120 2957 8120 3997 8120 4211 8120 4600 8120 1860 8120 1575 8120 2191 8...
Страница 46: ...Fuse Replacement 1 Open cover door pull the FUSE PULL lever and rotate to left Remove the fuse 2 Remove the Line Voltage Selection Card Position the card so the line voltage appears at top left 3 Rotate the FUSE PULL lever to its normal position Insert a fuse of the correct value in the holder corner Push the card firmly into the slot Close the cover door Figure 2 1 Line Voltage and Fuse Selection...
Страница 47: ...N and a listen address of period In binary this is 01110 in decimal it is 14 1 Disconnect the line Mains power cable 2 Remove any HP Il3 cables or connectors from the HP E3 connector 3 Remove the Modulation Analyzer s top cover a Remove the two plastic feet from the rear of the top coverby removingthe pan head Pozidriv b Unscrew the Pozidriv screw at the center of the rear edge of the top cover Th...
Страница 48: ...cable to the HP IB connector 8 To confirm the address turn on the instrument and select BUS ADRS Blue Key LOCAL To confirm a t a l k only or listen only setting key in 21 0 SPCL The display shows a binary number in the form AAAAA TLS where A A A M is the HP IB address in binary and T L and S indicate talk listen and service request status lbble 2 2 Allowable HP IB Address Codes A 95 0 0 0 0 0 0 0 ...
Страница 49: ...IES 57 CONNECTOR The Hewlett Packard interfaceBus logic levels are TTL compatible that is the true 1 state is 0 0 Vdc to 0 4 Vdc and the false 0 state is 2 5 Vdc to 5 Vdc Programmingand Output Data Format Refer to Section 3 Operation Mating Connector HP 1251 0293 Amphenol 57 30240 Mating Cables Available HP 10833A 1 meter 3 3 ft HP 108338 2 meters 6 6 ft HP 10833C4 meters 13 2 ft HP 10833D 0 5 met...
Страница 50: ...eet and fold away tilt stands for convenience in bench operation The plastic feet are shaped to ensure self aligningof the instruments when stacked The tilt stands raise the front of the instrument for easier viewing of the front panel Rack Mounting The Modulation Analyzer i s heavy for its size 23 6 kg 52 lb Care must be exercised when lifting to avoid personal injuv Use equipment slides when rac...
Страница 51: ...ble through Hewlett Packardoffices If the instrument is being returned to Hewlett Packard for servicing attach a tag indicating the iype of service required return address model number and full serial number Also mark the container FRAGILE to assure careful handling In any correspondence refer to the instrument by model number and full serial number Other Packaging The following general instructio...
Страница 52: ... all codes and formats HP IB information concerning remote information also appears in several other locations Address setting is discussed in Section 2 a summary of HP IB codes and output formats appears on the Operating Information pull out card and a list of relevant program codes for each function appears in the Detailed Operating Instructions Detailed Operating Instructions are described abov...
Страница 53: ...rmation Other information pertinent to operating the Modulation Analyzer to its fullest capabilities are contained in Section 1 Principles of Operation for a Simplified Block Diagram in paragraph 1 10 is a fundamental description of what the Modulation Analyzer is and how it works This information supplements the block diagrams provided on the pull out card and in the Detailed Operating Instructio...
Страница 54: ...can determine whether the time base oven is warm enough to create a stable source by selecting 15 0 The display will show a 0 if the time base oven is adequately warm The display will show Error 12 if the time base is cold To drive several instruments from a single external reference simplyuse a BNC tee at the Modulation Analyzer s TIME BASE 10 MHz INPUT If the internal time base fails an external...
Страница 55: ...ee Figure 2 1 Line Voltage and h e Selection 2 Check that the fuse rating is appropriate for the line voltage used See Figure 2 1 Line Voltage and f i e Selection fise ratings are provided in the paragraph Operator s Maintenance in this section 3 Plug in the power cable 4 Set the POWER switch to ON NOTE When the POWER switch is set to ON all front panel indicators light for approximately 10 second...
Страница 56: ...Model 8901B Operation 1 2 3 4 5 6 7 8 9 10 38 37 36 35 34 33 32 11 12 13 14 15 16 3 i 30 29 28 27 26 25 24 23 22 21 20 19 18 17 Figure 3 1 l ont Panel Features 3 5 ...
Страница 57: ... used with RF Power calibration factors See RF FYequency nning FYequency OffsetMode RF Power 10 MODULATION OUTPUT AUDIO INPUT connector provides either an output for the mod ulation recovered from the RF INPUT connector or an input for external audio signals to be processed by the audio circuitry The MODULATION OUTPUT annunciators indicate the type of recovered modulation available as the output T...
Страница 58: ...rs Audio Distortion and Level SINAD 1 kHz DISTN Blue Key and 400 Hz DISTN Blue Key enable the Modulation Analyzer to make audio measurements on either 1 kHz or 400 Hz audio signals See Audio Distortion and Level SINAD CALIBRATIONAMFM OUTPUT makes availablea preciselymodulated signalused to improve the Modulation Analyzer s AM or FM accuracy SeeAM Calibration FM Calibration CALIBRATE and SAVE CAL B...
Страница 59: ...Model 8901B Operation 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 Figure 3 2 Rear Panel Features 3 8 ...
Страница 60: ...or 240 Vac Serial Number Plate The first four numbers and letter comprise the prefix that denotes the instrument configuration The last five digits form the suffix that is unique to each instrument Line Power Module permits operation from 100 120 220 or 240 Vac The number visible in the window indicates the nominal line voltage to which the instrument must be connected See Figure 2 1 Line Voltagea...
Страница 61: ...in use the switch routes the external LO signal back out the LO output connector See High Selectivity Measurements Do not apply reverse power into the u OUTPUT or damage to the instrument may result Do not apply greater than 40 Vdc or 5 dBm of RFpower into the LO INPUT or damage to the instrument may result 16 CALIBRATION OUTPUT RF PWR and AMFM produces a rear panel output for RF Power and AM and ...
Страница 62: ...HP 8901B Modulation Analyzer Basic Operation and Application Guide HEWLETT PACKARD ...
Страница 63: ...sic OperationandApplicationGuide OHEWLETT PACKARDCOMPANY 1986 EAST 24001 MISSIONAVENUE TAF C 34 SPOKANE WASHINGTON USA 99220 First Ednion Printed Juiy 1986 Basic Operationand Application Guide Part Number 08901 90117 HEWLETT PACKARD ...
Страница 64: ...asurements Chapter 3 describes the HP 8901B sspecial capabilites that enable you to adapt the Modulation and Audio measurements to the special conditions of you application 4 Moreabout RF Power Measurements Chapter 4 describes the HP 8901Bsspecial capabilites that enable you to adapt the RF Power measurements to the special conditions of your application 5 MeasurementExamples Chapter 5 contains sp...
Страница 65: ... it will be easier for you to understand and implement the many additional features that the HP 8901B has to offer The HP 8907B Solution The hands on approach in t h i schapter demonstrates the extreme versatility of the HP 8901B Placing the HP 8901B on your bench actually puts the capabilities of several instrumentsat your fingertips Many of the measurement capabilities of the following products ...
Страница 66: ...he HP 8901B as well If you are using a power sensor rather than a Sensor Module refer to your HP 89018 Operation and Calibration Manual for information on which power sensors can be used and how to operate them with the HP 8901B The Calibration Data Once the HP 8901B is up and running you will need to first detennine if the calibration data for the Sensor Module you are using has been stored in th...
Страница 67: ...e ready to begin Start on the next page and follow the step by stepguide to learning to operate the HP 8901B You will soon discover how the HP 8901B can increase both the ease and speed of many of your measurements If you plan to selectively refer to portions of Chapter I rather than perform all of the procedures in sequence we recommend that you complete the procedures in the Frequency Counter po...
Страница 68: ...r the instrument to detect in its current measurement mode 5 Set the signal generator to 0 0 dBm Once the HP 8901B detects an input signal it removes the two dashes from its display Sometimes you will see the HP 8901B replace the two dashes with four dashes Four dashes indicate that the instrument is involved in internally setting up the measurement If the HP 8901B displays four dashes for more th...
Страница 69: ...tomatically tunes to and displays the frequency of the input signal approximately 100 MHz the absolute value depends on the accuracy of your signal generator and the accuracy of the HP 8901Bs time base reference Note also that AUTO TUNING the green LED on the front panel is on This LED lets you know that the instrument is in its automatic tuning mode 1 Hz Resolution 2 To increase the HP 8901B s di...
Страница 70: ...2 MHz The HP 8901Bwill display an Error 01 to let you know that the input signal is no longer within the tuning range of the frequency 110 MHz that the instrument was manually set to Press the Blue Shift key and the AUTO TUNING TRACK MODE key You have placed the instrument back in its Auto Tuning mode Notice that the AUTO TUNING green LED is on again The HP 89018 is now tuned to the frequency of t...
Страница 71: ...ncy Error measurement should only be made on a stable input signal That s all it takes to make Frequency Error measurements with the HP 8901B 10 Hz Resolufion 3 To display 10 Hz counter resolution enter 7 1 SPCL by pressing the digit keys 7 0 1 and the SPCL key Note that the SPCL key remains lit to indicate that a special function has been invoked Reset The HP 89018provides you with two ways to re...
Страница 72: ...ror condition Resets all operating functions Sets all operating functions to their defined 70 Learn More Chapter 2 in this guide provides reference information about the RF Frequency and Frequency Error measurements and the HP 8901B s tuning capabilities Refer to Chapter 2 when you want to find out more about 0 Tuning Modes Further information about the HP 8901B s tuning modes 0 Extending Operatio...
Страница 73: ...strument is now manually tuned to the frequency of the input signal green LED o f f Manual Tuning is a good choice when measuring modulation in the presence of multiple RF input signals 2 Key i n 100 MHz by pressing the digit keys 1 0 0 and the MHz Selecting a Detector The HP 8901B provides six detector functions for measuring your modulation and audio signals Peak Detector 3 Press the PEAK key Sw...
Страница 74: ...n rates up to 40 kHz and provides one more digit of resolution than the Average Detector The true RMS detector is also a good choice for measuring non sinusoidal signals AM Measurement Ranges Simply select AM and any of the above detector functions to make AM measurements within the following ranges I Max Depth 1 RF Carrier Frequency I Modulation Rate Measuring FM 1 Turn off AM on the signal gener...
Страница 75: ...he de emphasis filter after it is measured by the HP 8901B The de emphasized signal is still present at the MODULATION OUTPUT AUDIO INPUT port however function Repeat step 3 to select any of the four de emphasis filters 4 Press the PRE DISPLAY key again to turn Pre Display o f f 5 Press the 75ps key again to turn off the FM De emphasis Inserting Audio Filters To remove undesired signals such as ha...
Страница 76: ...m B w m 1 W o MODULATION RATE H2 Typical 20 kHr Low Paas Filter Reaponae Typical 3 kHz Low Para Filter Reaponre 1 w 80 e I p 4a 0 1 2 3 4 5 MODULATION RATEBH2 Typical 15 kHr Low Peas Filter Reaponae MODULATIONRATE IkHZ Diagram 1 2 The typical frequency response of each Audio Filter FM Measurement That s all it takes to make FM measurements and select audio filters through Ranges out the following ...
Страница 77: ... OUTPUT LED is now lit to indicate that the demodulated PM signal is available at the MODULATION OUTPUT AUDIO INPUT port An audio measurement device such as an oscilloscope can be connected to this port for monitoring the demodulated audio signal In Degrees 3 Key in 1 745 and then press the RATIO key The HP 8901Bis now displaying the phase deviation in degrees If the display is reading in dB press...
Страница 78: ...libration The procedure to calibrate your AM and 0 Extending Operation The special operating capabilities that enable FM measurements you to adapt the Modulation measurements to the specific conditions of your input signal making modulation measurements 0 Help Solutions to setup and operating problems encountered when Refer to Chapter 5 for examples of modulation measuremerit applications ...
Страница 79: ...the AM input signal The HP 8901B uses the last demodulator selected before entering an audio measurement mode to make its audio measurements Notice that the yellow AM MODULATION OUTPUT LED is lit When you are making audio measurements the MODULATION OUTPUT LEDs will show you which demodulator is selected 2 Press the gold S key and then AUDIO FREQ AM key both keys should remain lit The HP 8901Bis n...
Страница 80: ...playing the measured distortion of the 1kHz demodulated signal Notice that in the display the 1kHz annunciator is lit The true RMS detector is used to make this measurement 2 Press the Blue Shift key and the 400 Hz DISTN PEAK key the 400 Hz annunciator should be lit in the display The instrument is now ready to measure the distortion level of a 400 Hz signal 1 Press the gold S key and the AUDIO DI...
Страница 81: ...Audio Level Input Voltage 100 mV to 3V Learn More Chapter 3 in this guide provides additional information about the HP 8901B Audio measurement capabilities Refer to Chapter 3 when you want to know more about 0 Extending Operation The special operating capabilities that enable you to adapt the Audio measurements to the specific conditions of your input signal making Audio measurements 0 Help Soluti...
Страница 82: ... Module To ensure the highest possible measurement accuracy allow the HP 8901B to warm up for at least thirty minutes before performing the calibration procedure Press the RF POWER key on your HP 8901B If the HP 8901B is displaying Error 15 it has not yet been configured to make RF Power measurements Refer to Appendix B and perform the Calibration Factor Entry procedure before going on with this p...
Страница 83: ...nsor Module to the signal generator The HP 8901Bis now calibrated to make accurate power measurements with the Sensor Module you are using Erom now on you need only repeat step 2 to maintain RF Power calibration Measuring 1 Press the RF POWER key The instrument should read approximately 1000 06W 1000 pW with the signal generator set to 0 0 dBm 2 Press the LOG LIN key to toggle the display reading ...
Страница 84: ...DlSP FREQ kHz key You can use this method to check frequency tuning when in any of the measurement modes 20 dBm 10 pW to 30 dBm 1 W RF power Measurement Ranges From now on simply select RF Power to make accurate calibrated RF Power measurements throughout the following ranges using an HP 11722A Sensor Module I I I To Learn More Chapter 4 in this guide provides information about the HP 8901B s addi...
Страница 85: ...rnal voltages and frequencies Use these special functions to verify operation of the HP 8901B Refer to your UP 8907B Service Manualfor details on using service special functions 11to 37 40 to 99 The Special Display Special function modes are selected first by entering the appropriate code prefix decimal point suffix and then pressing the SPCL key lower right comer on the front panel 1 Key in 7 2 S...
Страница 86: ...s you informed of its operating status by placing error and dash codes in its display The Operating Information pull out card enables you to quickly access a brief description of each code The measurement reference chapters 2 through 4 in this guide provide a listing of the errors and problem conditions for each of the measurement modes Each code listing includes a description and recommended reco...
Страница 87: ...nterested in The information is organized into three subject areas 0 Tuning Modes Refer here for further understanding of the 0 Extending Operation Refer here for the special operating HP 8901B stuning modes capabilities that enable you to adapt the HP 8901B to the specific conditions of your input signal 0 Help Refer here for help in solving setup or operating problems encountered in RF Frequency...
Страница 88: ...ed after multiple sweeps the instrument places two dashes in its display while it continues to sweep When a signal does appear within the IF passband the instrument performs a series of tests to determine whether the signal it has found is the appropriate signal to tune to This testing enables the HP 89018 to Auto Tune to the fundamental in harmonically rich specbums or to a carrier with high dept...
Страница 89: ... HP 8901B sResponse Instrumentwill measure and display characteristics of input signal at the highest frequency Instrument may measure and display characteristics of input signal at the highest frequency Instrument may measure and display characteristics of signal above 1300 MHz Instrumentmay continuously display four dashes Instrumentmay continuously display two dashes or 0 MHz or it may alternat...
Страница 90: ... RF signals are present If the input signal is d r i f t y however it may be necessary to select the Track Mode function Track Mode The Track Mode function enables the HP 8901B to track drifting input signals from 10 MHz to 1300 MHz Track mode can be selected with either Auto Tuning or Manual Tuning by pressing the TRACK MODE key A drifting signal will cause the HP 8901B to place four dashes in it...
Страница 91: ...ge HP 8901B sResponse Instrumentwill measure and display characteristics of input signal at the highest frequency Instrument may measure and display characteristics of input signal at the highest frequency Instrumentmay measure and display characteristics of signal above 1300 MHz Instrumentmay continuously display four dashes Instrumentmay continuously display two dashes or 0 MHz or it may alterna...
Страница 92: ...ode is able to automatically find and tune to the fundamental in a harmonically richspectrum as long as the fundamental is at least 10 dB above the level of the second and third harmonics The HP 8901B will also auto tune to the input signal if it is at least 30 dB above all non harmonically related RF signals If however your input signal does not meet these criteria the HP 8901B may have difi5cult...
Страница 93: ...y will appear within the IF passband If the switching speed of the input signal is too fast the HP 8901B will not detect a change in the input frequency and will continue to erroneously display the previous frequency If you suspect that this has happened press the Blue Shift key and then the AUTO TUNING key after the input frequency has changed This causes the HP 8901B to retune to the input signa...
Страница 94: ...8901B to microwave frequencies Refer to Chapter 5 for measurement examplesusing these tuning techniques Frequency Underrange If the input frequency is below the HP 8901B s frequency measurement range the instrument will display Error 10 The specified low frequency limit of the RF Frequency measurement is 150 kHz However you can extend this measurement range to 20 Hz by simply selectingthe Audio Co...
Страница 95: ...port to the output of your signal source HP B The HP 8901B enables you to fully automate your measurements Refer to your HP 8901B Operation and Calibration Manual for setup and programming information Time Base A time base input is provided on the rear panel of the HP 8901B This input allows you to connect the HP 8901B to an external 10 MHz time base The time base circuitry within the HP 8901B aut...
Страница 96: ... caused only by an input problem and the errors that can be caused onZy by an operating problem are listed in the chart below If your instrument is displaying one of these errors proceed directly to Table 2 3 RF Frequency and Frequency Error Error Codes and take the recovery action recommended Input Problem Operating Problem I I Error 1 10 I 09 12 20 thru 24 or 26 If you did not find your error li...
Страница 97: ...ing flexibility of the HP 8901B it is not possible to list all recovery actions for each error code After using the table to determine the cause of the problem you may discover other error recovery procedures that are better suited to your application Table 2 3 RF Frequency and Frequency Error Error Codes 1of 2 Display Code Problem Description Input signal level out of measurement range and is att...
Страница 98: ...thin its measurementrange Frequency entered exceeds measurementrange increase measurejnent range Refer to Frequency Overrange 2 7 and Frequency Underrange 2 7 Input signal level during reference measuremeni must be between 1 25V and 2 50V Option 030 only Invalid entry Invalid Special Functionprefix entered Invalid Special Functionsuffix entered Operating Problem Increase RF attenuation Check inter...
Страница 99: ...nterested in The information is organized into three subject areas 0 Calibration Refer here for the procedure to calibrate your AM and F M measurements 0 Extending Operation Refer here for the special operating capabilities that enable you to adapt the HP 8901B to meet the specific conditions of your input signal problems encountered in Modulation or Audio measurements 0 Help Refer here for help i...
Страница 100: ...nt error Once the calibration factor has been created you have control over when it is used by the instrument There is not a calibration procedure for the Mmeasurement The following chart lists the special function codes for enabling disabling or displaying the calibration factor After you have enabled the calibration factor the HP 89018 will automatically apply it to its AM or FM measurements AM ...
Страница 101: ... Likewise a calibration factor of 100 17 indicates that the HP 8901B is measuring 17 above the Calibrator s actual output Remember While the HP 8901B is in the Calibration mode Calibrator key lit the calibration factor is stored in the instrument s non volatile memory each time it is updated approximately every 17 seconds To ensure that the measurement circuitry is fully settled allow the instrume...
Страница 102: ...de is very unstable Unstable Carrier 3 6 Check Tuning For most applications the HP 8901Bs Auto Tuning mode enables the instrument to automatically tune to the input signal Auto Tuning mode is the right choice for measuring modulation on a single stable camer The HP 89018 will inform you that it is having difficulty tuning by placing dashes error codes or a very inaccurate reading in its display Yo...
Страница 103: ...r To check what RF frequency the HP 8901B is actually tuned to press the FREQ key If the instrument does not display the correct carrier frequency manually tune the HP 8901B to the carrier frequency key in the frequency of the carrier and then press the M H t key Refer to Chapter 2 for details on the Auto Tuning and Manual Tuning modes Changing Frequency Although the HP 8901B is not designed for s...
Страница 104: ...icrowave frequencies Refer to Chapter 5 for measurement examples using these tuning techniques Frequency Underrange The specified low frequency limit of the HP 8901B is 150 kHz However you can extend this measurement range to below 50 kHz The procedure is simple First manually tune the HP 8901B to 100 MHz and override Error 01 by keying in 8 1 SPCL This enables the input signal to pass directly th...
Страница 105: ...the HP 8901Bs INPUT port to the output of your signal source The HP 89018 enables you to fuIly automate your modulation and audio measurements Refer to your HP 8901BOperation and Calibration Manual for setup and programming information A time base input is provided on the rear panel of the HP 8901B This input allows you to connect the HP 8901B to an external 10 MHz time base The time base circuitr...
Страница 106: ...em and the errors that can be caused only by an operating problem are listed in the chart below If your instrument is displaying one of these errors proceed directly to Table 3 1 Modulation and Audio Error Codes and take the recovery action recommended If you did not find your error listed in the chart or if your instrument is displaying dashes or a questionable measurement perform the followingpr...
Страница 107: ... table to determine the cause of the problem you may discover other error recovery procedures that are better suited to your application 1 Measurementis very inaccurate 2 Measurement is slightly inaccurate Table 3 1 Modulation and Audio Error Codes 1of 2 or 0 MHz 01 02 03 04 Display Code Problem Description Input signal level below measurementrange Instrumenthas detected an input signal and is att...
Страница 108: ...nput signal to within measurement range or increase measurement range Refer to FrequencyOverrange 3 6 and Frequency Underrange 3 6 dB Ratio measurementresults in calculatedvalue 50 log 0 not allowed Indicatesinternaltime base oven cold Option 002 instrumentsonly Level of audio signal at Audio Input too low IF level not within its measurementrange Key in a different ratio reference Wait for oven to...
Страница 109: ...ation is organized into three subject areas 0 Calibration Refer here for information about the RF Power calibration technique 0 Extending Operation Refer here for the special operating capabilities that enable you to adapt the HP 8901B to meet the specific conditions of your input signal encountered in RF Power measurements 0 Help Refer here for help in solving setup or operating problems The Dire...
Страница 110: ...be tuned to the frequency of the input signal when making RF Power measurements Even though the RF Power measurement is not a tuned measurement the instrument uses the frequency setting to determine the appropriate calibration factor to select from the table of power sensor calibration factors stored in its memory If a calibration factor is not stored for the specific frequency being measured the ...
Страница 111: ...data for the new Sensor Module into the HP 8901B Short Term If you are only using the new Sensor Module temporarily you can manually enter the appropriate cal factor for each RF Power measurement Refer to your HP 8901B Operation and Calibration Manual for the procedure and considerations for manually entering cal factors Interchangeably If you plan to use two sensors interchangeably a second stora...
Страница 112: ...tector Note that the HP 8901B lights the SPCL key rather than the RF POWER key when it is using the uncalibrated RF Peak detector to measure power Although the accuracy of this measurement is signrficantlylower than a calibrated power measurement made using a power sensor it can be useful as a means of determining if there is any input signal present at the HP 8901Bs input If a Sensor Module is co...
Страница 113: ...se the HP 8901B to display an error code are classified into one of two categories 0 Input Problem caused by input signal conditions or 0 Operating Problem caused by the selection of incompatible operating functions Certain errors are caused only by an input problem other errors are caused only by an operating problem and some errors can be caused by either The errors that can be caused only by an...
Страница 114: ... pressed Take the action recommendedfor Input Problem Because of the wide variety of input signals and the operating flexibility of the HP 8901B it is not possible to list all recovery actions for each error code After using the table to determine the cause of the problem you may discover other recovery procedures that are better suited to your application Table 4 3 RF Power and TRFL Error Codes 1...
Страница 115: ...utp ut not sensed at INPUT High stabilitytime base problem Option 002 instruments only Frequency of input signal is not within measure ment range 1 Attempting to measure RF power dBm with no power at sensor input 2 Mathematicserror log 0 not allowed Indicates internal time base oven cold Option 002 instruments only Power sensor was disconnected durina RF Power measurement Cannot zero power sensor ...
Страница 116: ...on prefix entered Invalid special function suffix entered Invalid HP IB code End of RF Power calibrationtable If displayedafter first attempt to read table using 37 6 SPCL the table is empty Check sensor connectionat RF POWER OUTPUT port Check limits of function Check compatibilityof function s with selected measurement mode Check special function number and re enter Check special function number ...
Страница 117: ... in Chapter 1 is necessary This chapter enables you to refer directly to the measurements you are interested in The examples are organized into the two measurement groups 0 RF Frequency and Frequency Error measurements 0 Modulation and Audio measurements The Directory Use the directory diagram below to quickly locate the measurement you are interested in A look up table is located on the fmt page ...
Страница 118: ... the reference level 2 Select the RF Frequency measurement and press the green AUTOMATIC OPERATION key on the HP 8901B 3 When the HP 8901B displays the frequency of the input signal select RF Power on the HP 8901B The previous frequency measurement enables the instrument to automatically select the correct calibration factor for its power measurement Use the LOG LIN key if you wish to toggle betwe...
Страница 119: ...y 25 kHz 4 Adjust the transmitter to its next channel The HP 8901B will display the measured value for the next channel Press the Blue Shift key and the DISPLAY FREQ key if you wish to check the HP 8901Bs tune setting 5 Continue to adjust the transmitter and then increment the HP 8901B to check each of the remaining channels Frequency Error ppM The HP 8901B s Ratio Mode allows you to verify freque...
Страница 120: ... GHz the LO should be set to 2620 53 MHz This positions the HP 8901Bs internal IF in the center of a tuning octave Set the output level of the external LO to 8 dBm Press the AUTOMATIC OPERATION key and then key in 27 3 SPCL the external LO frequency and the MHz key on the HP 8901B If you make a mistake press the CLEAR key and re enter the keystrokes Manually tune the HP 8901B to the expected frequ...
Страница 121: ...ay between when the HP 8901B senses an RF signal at its INPUT and when it enables the output at the MODULATION OUTPUT AUDIO INPUT port 1 Connect your transmitter modulated source to the HP 8 9 0 1 B s INPUT Connect an audio counter to the MODULATION OUTPUT AUDIO INPUT port 2 Press the FM key on the IF 8901B 3 Select a detector and if desired Audio Filters and an FM 4 Key on the transmitter Allow t...
Страница 122: ...se of most transmitters directly Diagram 5 2 shows the typical residual FM characteristicsfor the HP 8901B 3 Press the PRE DISPLAY key and then the 750ps key The 75011s filter attenuates a 1kHz signal by 13 66 dB a factor of 0 2076 4 Press the FM key on the HP 8901B to measure residual FM 5 Press the Blue Shift key and the RMS AVG key This selects the true 6 Key in 44 and then the RATIO key For st...
Страница 123: ...ternally demodulated audio signal External Audio INPUT port on the HP 8901B 6 Connect your audio source to the MODULATION OUTPUT AUDIO 7 Press the AUDIO INPUT key key should remain lit 8 Perform steps 3 and 4 above to measure the SINAD of the external audio signal Signal fo Noise The HP 8901B sRatio Mode makes it easy to make relative measurements such as signal to noise on AM transmitters or hum ...
Страница 124: ... The measurement range of the HP 8901B can be extended above 1300 MHz for modulation and audio frequency measurements by using a spectrum analyzer as a fixed tuned receiver This is one of three techniques available for extending the RF frequency range of the HP 8901B The other two are also shown in this chapter SIGNAL SOURCE HP 89018 1 Connect the signal source spectrum analyzer and HP 89018 as sh...
Страница 125: ...he carrier as well as the Hewlett Packard office Keep the shipping materials for inspection by the camer Connect Power If you are not sure of the power or fuse requirements for your instrument refer to Section 2 of the HP 8901B Operation and Calibration Manual for further information Connect Connect the Sensor Module to the SENSOR and INPUT ports Refer to Appendix B in this guide for information o...
Страница 126: ...ts with the HP 8901B If the HP 8901B displays Error 15 when you press the RF Power key no cal factors have been entered Perform the Entry Procedure now If you are changing sensor modules or if the cal factors for your Sensor Module have changed due to repair or calibration perform the Entry Procedure to enter the new cal factors If you are not certain that the cal factors in the HP 8901B match the...
Страница 127: ...o your HP 8901B and press the Blue Shift 6 Key in 37 3 SPCL the Blue Shift key and then the MHz key Remember Press the CLEAR key if you miskey a digit If you suspect that you have entered wrong data complete the Entry Procedure and then perform the Verification Procedure to check the stored data The Error Correction Procedures will enable you to change any incorrect data Enter FrequencylCal Factor...
Страница 128: ...s not perform step 7 in the Entry Procedure for that frequency and enter its correct cal factor only The HP 8901B will place the new entry in the correct position in the table and remove the incorrect cal factor For example if an incorrect cal factor value was entered for 10 MHz you would correct it by entering 37 3 SPCL 10 MHz the correct cal factor value Blue Shift key MHz The HP 8901B automatic...
Страница 129: ...953 8424 HP 8907B Modulation Analyzer Flyer March 1983 5953 8382 HP 8907B Operationand CalibrationManual July 1986 08901 90113 HP 8907B Modulation Analyzer Service Manual 08901 90114 HP 77722ASensor Module Operating and ServiceManual October 1983 11722 90009 HP 77792ASensor Module Operating and Service Manual March 1983 11792 90008 ...
Страница 130: ...61 Lankershim Blvd North Hollywood CA 91601 Hewlett Packard Company 2000 South Park Place Atlanta GA 30339 Canada Hewlett Packard Canada Ltd 6877 Goreway Drive Mississauga Ontario Canada L4VlM8 Europe and Africa Hewlett Packard S A P O Box 529 1180 AM Amstelveen The Netherlands Australasia Hewlett Packard Australia Ltd 31 41 Joseph Street Blackburn Victoria 3130 Australia Yokagawa Hewlett Packard ...
Страница 131: ... 3 17 Reference Tables 3 17 DATA OUTPUT 3 18 Data Output Format 3 18 HP IB INFORMATION 3 19 0HP B Capabilities 3 19 oHP IBAddress 3 20 MODULATIONANALYZER REMOTE CAPABILITIES IEEE 488 3 20 TriggeringMeasurements 3 21 Clear 3 24 oRemote Local 3 25 Clear Lockout Set Local 3 26 Service Request Message SRQ 3 26 Local Lockout 3 25 Status Byte 3 31 Abort 3 32 Pass Control Take Control 3 32 Status Bit 3 3...
Страница 132: ... be interested in more specific information In this case read the paragraphs titled Data Output Hewlett Packard Interface Bus Modulation Analyzer Remote Capabilities and or Additional Information as appropriate to your needs Advanced Users You may be able to program the instrument just using the tables in the back of this section which list the codes required to make measurements the modifiers for...
Страница 133: ...urns off the functions The HP IB Codes for turning off these functions are given in Table 3 1 Turning O f fhnctions lbble 3 1 lhming Off finctions FunctionsOff Audio Input Off Mod Output On Calibrate Off Disable Error Function Off Range Hold Off Auto Range On All HP Filters Off Track Mode Off Lock Mode On All LP Filters Off dB Ext Attenuator Off Pre display and De emphasis Off Ratio Off Code A0 co...
Страница 134: ...eystroke sequences There are three different syntax which execute functions Refer to Table 3 3 Function Code Syntax Examples for examples 0 Using a two character code or suffix alone which is the common case 0 Using a number and a suffix 0 Using a prefix usually a special function a number and a suffix ble 3 3 hnction Code Syntax Examples Code MZ 100 MZ 27 3SP 100 MZ CF 98 CF 37 3SP 98 CF ODeratio...
Страница 135: ...Syntax Sequence Dependency For accurate measurement results functions should be programmed in the following order to insure proper sequencingof events and switching in the instrument as appropriate to the measurement The letter X in the following example represents a number Function codesthat have the same alpha character shouldbe entered in numeric order to ensure proper execution e g P1 should c...
Страница 136: ... MZ M2 D1 P1 P4 T 3 Automatic Operation Frequency ManualTuning Units FM Peak Detector FM De emphasis and Pre display 75 ps FM De emphasis Trigger w Settling Example Measurement Program The following example provides you with a sample of how the previousinformation might be used to program the HP 8901B to make a particular measurement This example demonstrates measuring AM in the 5 0 Hz to 15 KHz b...
Страница 137: ... or 16 EnablingDisabling Variable Parameters Front Panel or Remote for a summary of how to read the Calibration Factors the Frequency Offset the dB external Attenuation the Limits set and whether Ratio has been selected Table 3 1 5 Enabling Disabling Variable Parameters Front Panel This table lists ways of verifying from the front panel the values of the Calibration Factors Frequency Offset dB Ext...
Страница 138: ...Capability RL1 CompleteCapability PPO No Capability DC1 Complete Capability DT1 CompleteCapability CO No Capability El Open Collector Drivers including Listen Only mode HP IB Capabilities The interface functions that the HP 8901B implements are defined in Table 3 6 IEEE Std 488 Interface Function Capabilities The Modulation Analyzer s HP IB command capabilities are compatible with the IEEE Standar...
Страница 139: ...lyzer Remote Capabilities 1 of 2 Capability Data Trigger Clear Enabled Yes Yes Yes ModulationAnalyzer Capabilities Response All front panel functions special functions and remote only functions are programmable except the POWER switch The Modulation Analyzercan sendthe StatusByte and messageand setting information All measurement results special displays and error outputs exceptdashed displays are...
Страница 140: ... false The Modulation Analyzer cannot pass or take control of HP IB The Modulation Analyzer sets the SRQ bus line true if any of the conditions defined in the Status Byte occurs and has been enabled by the SRQ Mask Special Function 22 to send the Service Request message The ModulationAnalyzer respondsto a Serial Poll Enable SPE bus command by sending an 8 bit byte when addressed to talk Bit 6 is t...
Страница 141: ...owever will trigger a new measurement update displays and return the instrument to Trigger Hold Measurement data is replaced with data acquired from subsequenttriggered measurement cycles NOTE When a trigger i s received the Modulation Analyzer will not allow its measurementcycle to be interrupted Indeed handshake of bus commands is inhibited until the measurement cycle is complete EnteringTrigger...
Страница 142: ...libration in the Detailed Operating Instructions 0 If the settling time provided with T3 i s not adequate to produce accurate measurements use TO Free run and write a sub program which compares measurement values until they are within a specified tolerance Delays not included in the T3 settling time in the source and or the thermocouple in the Power Sensor can prevent accurate measurements Trigger...
Страница 143: ...asurement 100 no terminator would be cleared because no units terminator has been entered Me 3 8 Response to a Clear Message Parameter High Pass Filters Low PassFilters FM De emphasis Pre display Calibration Measurement Detectors Ratio Limit Lower Limit Reference Upper Limit Reference Limit Measurement Mode AutomaticOperation Manual Operation MHz Input Frequency fi and JJStep Size SPCL Modulation ...
Страница 144: ...al operation Mode Transitions Local to Remote Transitions The Modulation Analyzer switches to remote operation upon receipt of the Remote message No instrument settings are changed by the transition from local to remote The Tkigger mode will always be Free Run TO on entry to remote operation Remote to Local Transitions The Modulation Analyzer always switches to local from remote whenever it receiv...
Страница 145: ...s been a Frequency Offset mode change 0 an enabled limit has been exceeded 0 an instrument error has occurred 0 an HP IB code error has occurred 0 measurement data is ready to be read The Modulation Analyzer uses its Status Byte and the SRQ Mask SpecialF unction 22 to determine whether or not to issue a SRQ message Refer to Figure 3 4 Issuing a Service Request Message throughout the following disc...
Страница 146: ...ment or HP IB code errors The Service Request Message can also be used for signaling measurement data ready Remote measurements are usually performed simply by triggering measurements then reading the output data In certain applications the controller must control other instruments while the HP 8901B is making a measurement Using the instrument s ability to issue the Service Request message when d...
Страница 147: ...sing Special Function 22 HP IB Code Error bit IS permanently unmasked STATUS BYTE 0 1 if condition has occurred and SRQ Mask bit has been set to 1 I I RQS B I T I 1 if one or more other Status Byte bits are 1 c I f l Asserted if RQS bit is 1 SERVICE REQUEST MESSAGE SRQ BUS LINE SRQ ANNUNCIATOR ON FRONT PANNEL p q On ifSRQ line is asserted and front panel display is updated Figure 3 4 Issuing a Ser...
Страница 148: ...nd 5 can be set Bit 1 weighk2 is permanently set To set the SRQ Mask bits and unmask the Status Byte bits which you want to cause the Service Request Message to be issued 0 Sum the weights of the desired conditions using Table 3 9 below Use this sum as the suffix of Special Function 22 NOTE Since Bit 1 HP IB Code Error is permanently enabled if the weight is not summed in it will be assumed by the...
Страница 149: ... Asserted if unmasked when limits are enabled 14 XSP andexceeded Asserted if unmaskedwhen in FrequencyOffset Modeand Manual Tune frequency is changed or when entering or exiting the mode through 27 0 1 3 SPCL Asserted if unmaskedwhen the UNCALannuniciatorturns on This bit will always be set if any of the other bits are set Always 0 Reading the SRQ Mask Read the SRQ Mask by entering 22 64SP This in...
Страница 150: ...masked by the SRQ Mask will ALWAYS read as a zero when the Status Byte is read Only an unmasked bit can be read as a one and then only if its initiating Instrument Condition occurs AFTER it is unmasked a Reading the Status Byte is the only accurate way to determine the condition of the SRQ bus line Service Request message The SRQ annunciator is only updated as the frontpanel is updated It is NOT t...
Страница 151: ... receive a new command from the controller Typically this is an initialization command used to place the bus in a known starting condition The Modulation Analyzer stops listeningor talking when it receives the Abort message Pass Control Take Control The Modulation Analyzer does not respond to the Pass Control Take Control message because it cannot act as a controller Status Bit The Modulation Anal...
Страница 152: ... Only Talk Only overrides Listen Only If all A bits are 1 and T is 1 the instrument will Talk Status Only that is output the status byte only A list of possible conditions of the TLS digits of the display is provided in the following table Example If 1110 001is the address displayed then the HP IB address is 1110 in binary that is 14 in decimal The T digit is 0 and the L digit is 0 indicating that...
Страница 153: ... the Software Supervisor is included to elaborate on these considerations 0 Every two letter command is acted upon in order in sohare state 0 Hardware State equals the Software State only after the end of the HP IB code string AND a pause occurs allowing the instrument to implement the commandsit has received e g time delay between code strings when data is read from the instrument 0 Only one meas...
Страница 154: ...of the supervisor and so avoids the extra time associated with the if the program loops back before taking a measurement or if After power up the external system controller can be thought of as a medium through which the user requests a certain instrument setup which is first implemented in softwarestate and then in hardware state Controller commands IKeyboardor HP IB Interrupts1 are treated as no...
Страница 155: ...EYBOARD OR SOFTWARE STATE I NONMEASUREMENT MEASUREMENT DISPLAY I I I 7 NONMEASUREMENT MEASUREMENT DISPLAY I I I FREQUENCY TUN ING S I GNAL LEVELING 1YES AUDIO RANGING 0 CONT I NUE Figure 3 5 Software Supervisor Flowchart 3 36 ...
Страница 156: ...M3 M4 M5 s1 s2 s3 s4 s5 D1 D2 D3 D4 D5 D6 D8 D9 LG LN N O N1 R O R1 R2 H O H1 H2 L O L1 L2 L3 P O P1 P2 P3 P4 P5 Function CALIBRATION CALIBRATE Off CALIBRATE On Yo CAL FACTOR ZERO SAVE CAL MANUAL OPERATIONS AUTO TUNING ENABLE ERRORS DISABLE ERRORS CLEAR KEY DISPLAY FREQ DISPLAY INCREMENT INPUT FREQUENCY Hz h Hz u Hz TRACK Mode Off Lock Mode TRACK Mode On fi kHz U kHz MHz INPUT FREQ RECALL STORE SP...
Страница 157: ...Mode Off lock mode TRACK Mode On fi kHz 4kHz LP Low Pass FILTERSOff 3 kHz FILTER On 15 kHz FILTER On 20 kHz FILTER On Display LOG Result Display LIN Result Code M1 M2 M3 M4 M5 MV MZ N O N1 P O P1 P2 P3 P4 P5 RO R1 R2 RC s1 s2 s3 s4 s5 sc SP ss T O T1 T2 T3 TR uv VL WT xo x1 x2 x3 x4 x5 ZR Function AM FM PM RF POWER FREQ mV Units MHz INPUT FREQ dB EXTATTEN Off dB EXTATTEN On PRE DISPLAYOff and PRE ...
Страница 158: ...ency External Audio Distortion External Audio SINAD External Audio RMS Level External ProgramCode M1 co c1 13 0SP 13 1SP 13 2SP 16 2SP M2 co c1 12 0SP 12 1SP 12 2SP 17 2SP M3 M4 ZR 37 2SP 37 4SP 35 XSP s3 M5 33 XSP 34 XSP s5 S1 A2 s2 A2 29 0SP A2 3O XSP Receiver Used Yes Yes No Yes Yes No Yes Yes No Yes Yes No Yes No No No No No Yes Yes Yes Yes Yes No No No No Volatile No No No No No Yes No No No ...
Страница 159: ...nctions Display Ext Atten HP IB Identify 8901B or 8902A Display SRQ Mask Software Date Code Read Ratio Reference Read Lower Limit Read Upper Limit Read Lower Limit Measurement Code Read Upper Limit Measurement Code ProgramCode 18 XSP 15 0SP 15 1SP 21 XSP 27 2SP SP ss 25 2SP ID 22 64SP 42 XSP 11 2SP 14 5SP 14 6SP 14 7SP 14 8SP Receiver Used Yes No No No No No No No No No No No No No No No Volatile ...
Страница 160: ...t Attenuator N A N A N A N A N A N A N A RF Power Measurement M4 Tuned RF Level S4 Peak RF Level 35 XSP 5 1O XSP N A N A Tuning N A Yes Yes a W 0 Variable Parameters I Filters HO 2 and LO 3 De emphasis 0 5 Calibration Factors Detectors Dl 9 Limit Ratio Yes N A N A Yes N A N A Yes Yes Peak or Avg or RMS Peak or Peak or Yes N A N A Yes Yes N A Peak or Avg or RMS Peak or Peak or Yes N A N A Yes N A N...
Страница 161: ...Limit Ratio Yes Yes Yes Yes I IF Level Measurement Sa 7 IF Avg Tuning Yes N A N A RF Frequency Measurement M5 LO Frequency 33 XSP IF Frequency 34 XSP IFrequency Error Measurement S5 Tuning Yes Yes Yes Yes Yes I Audio Measurements Audio Frequency Sl Audio Distortion S2 ExternalAudio RMS Level 3O XSP SlNAD 29 XSP N A Yes FM N A Yes FM Tuning Tuning N A Tuning ...
Страница 162: ...P nn MHz FrequencyOffset 27 XSP 0 dB 25 2SP dB EXTATTEN dB Ext Atten Light nn dB EXTATTEN dB EXTATTEN dB ExternalAttenuation Ratio 11 XSP 11 2SP Previous Ratio Ratio Key Ratio Key Light Ratio Key or nnn Ratio Key 100 14 1SP or 14 2SP from Ratio 0 15and1301 Code5 frec 14 5SP or 14 6SP 14 3SP or 14 4SP 14 0SP 14 9SP 14 7SP or 14 8SP measurement mode Limits 14 XSP Yo Cat Factor alone shows the value ...
Страница 163: ...XSP 0 dB 5 2SP N1 NO dB Ext Atten Light nn N1 dB ExternalAttenuation 25 XSP 100 1 2SP R2 RO Ratio Key Light R1or nnn R1 Ratio 11 XSP Limits 14 XSP I 0 15and 1300 Code 5 freq 4 5SP or 4 6SP 14 3SP or 14 4SP 14 0SP 14 9SP 14 1SP or 14 2SP from Ratio 14 7SP or 14 8SP measurement mode code o o Cal Factor alone shows the value currently being used For AM and FM it also indicatesenabled disabledstatus b...
Страница 164: ...te Functions AUTOMATIC OPERATION MHz INPUT FREQ fi kHz U kHz SPECIAL SPECIAL SPECIAL CLEAR PEAK PEAK PEAK HOLD Average Detector RMS Calibrated Hz INPUT FREQ h Hz u Hz Peak RF Level O o RATIO dB RATIO Auto Tuning low noise lock mode Auto Tuning track mode Manual Tuning low noiselock mode 10 Hz frequency resolution 1000 Hz frequency resolution Hold Setting RANGE HOLD IF Frequency O o PREVIOUS RATIO ...
Страница 165: ...be lighted RF Power CalibrationCheck Connect the sensor module input to the RF POWER CALIBRATIONOUTPUT connector See Figure 3 6 Press the RF POWER key If the instrument does not display Error 15 proceed with step 6 If the instrument displays Error 15 indicating the RF power calibration factors have not been entered proceed with step 5 If the instrument displays Error 15 enter the RF power calibrat...
Страница 166: ...ut of the oscilloscope See Figure 3 7 10 Press the LOG LIN key to display power in dBm The Modulation Analyzer should display between 11 00 and 9 00 dBm RF Peak Level Check 11 Key i n 35 0 and press the SPCL key uses a peak detector to measure power The Modulation Analyzer should display between 16 00 and 6 00 dBm Frequency Check 12 Press the FREQ key Key in 7 1 and press the SPCL key to set the R...
Страница 167: ...TPUT Figure 3 6 RF Power Calibration Setup HP 89016 MODULATION ANALYZER OSCILLOSCOPE 0 I SIGNAL GENERATOR 0 0 RF OUTPUT MODULATION OUTPUT AUDIO INPUT VERTICAL INPUT oo flo D 0 0 0 0 0 O D 0 0 O D 0 0 0 O O D O 0 0 ODD0 INPUT 50 OHM SENSOR MODULE Figure 3 7 RF Power Check Setup 3 49 ...
Страница 168: ... calibration factor should be displayed The displayed value should be between 99 00 and 101 00 18 Press the FM key then CALIBRATE key After approximately 20 seconds the FM calibration factor should be displayed The displayed value should be between 99 00 and 101 00 Press the CALIBRATE key again to turn off FM calibration If you remove the sensor with the calibrator still on it might return Error 0...
Страница 169: ...illoscope should show a sinusoidalwaveform with a peak to peak amplitude between 0 9 and 1 1V and a period of 1 ms 27 Press the LOG LIN key Press the RATIO key Press the PRE DISPLAY key Set the FM rate as listed in the followingtable For each setting perform the following steps a Set the FM DE EMPHASIS off if it is on Leave PRE DISPLAY on b Set the signal generator s FM modulation rate to a value ...
Страница 170: ... and set the LP FILTER to ALL OFF Set the signal generator s FM off and set the AM depth to 50 as measured on the Modulation Analyzer s display at a 1 kHz rate Press the S Shift key then the AUDIO DISTN key the FM key The displayed distortion should be less than 3 The display should also indicate 1 kHz If 400 Hz is displayed press the Blue key then the 400 Hz DISTN key the PEAK key 30 Set the sign...
Страница 171: ...ay between 69 3 and 72 1 REL Turn the ratio function off by pressing the RATIO key again 37 Press the PEAK key then press the PEAK HOLD key Switch the signal generator s FM off The Modulation Analyzer s display should retain the largest value obtained after pressing PEAK HOLD Turn off the peak hold function by pressing the PEAK key IF Level Check 38 Press the S Shift key then the IF LEVEL key the ...
Страница 172: ...al generator sFM on and adjust the peak deviation for 5 kHz asread on its FM meter The Modulation Analyzer should display Error 04 45 Press the 46 Key in 8 4 and press the SPCL key The instrument should display Error 07 High Selectivity Level Check Option Series 030 47 48 49 50 51 Set the signal generator to 10 MHz CW at 0 0 dBm On the Modulation Analyzer press the Blue key then press the INSTR PR...
Страница 173: ...1 O 51 O 61 O 71 O 81 O 91 o 032 and 033 032 and 035 Maximum 9 0 19 0 29 0 39 0 49 0 59 0 69 0 79 0 89 0 6 4 10 4 I 033and 035 I 12 4 I 16 9 55 Fine tune the signal generator for a reading of 0 0 dB Step down the signal generator s level in 10 dB steps as listed in the following table At each step the Modulation Analyzer s display should be within the limits indicated in the table Signal Generator...
Страница 174: ...following assumptions 0 The Modulation Analyzer performs properly when operated via the front panel keys that is in local mode This can be verified with the preceding Basic Functional Checks of the Modulation Analyzer in paragraph 3 11 0 The bus controller properly executes HP IB operations 0 The bus controller s HP IB interface properly executes the HP IB operations If the Modulation Analyzer app...
Страница 175: ...oller exactly as described Check that the instrument responds correctly Address Recognition Check This check determines whether or not the Modulation Analyzer recognizeswhen it is being addressed and when it is not This check assumesonly that the Modulation Analyzer can properly handshake on the bus Before beginning this check set the Modulation Analyzer s POWER switch to STBY then to ON Set the R...
Страница 176: ...now off but that its LISTEN annunciator remains on HPL rem 714 Icl714 rem 714 BASIC REMOTE714 LOCAL 714 REMOTE714 Sending the Data Message Check Data Output This check determines whether or not the Modulation Analyzer properly issues Data messageswhen addressedto t a l k This check assumes that the Modulation Analyzer is able to handshake and recognize its own address Before beginning this check s...
Страница 177: ...143MZ Local Lockout and Clear Lockout Set Local Messages Check This check determines whether or not the Modulation Analyzer properly receives the Local Lockout message disabling all fiont panel keys The check also determines whether or not the Clear Lockout Set Local message is properly received and executed by the Modulation Analyzer This check assumes that the Modulation Analyzer is able to hand...
Страница 178: ...gthe ModulationAnalyzer to remote Address the ModulationAnalyzer to listen completingthe Remote message Then send a Data messagethat sets the ModulationAnalyzer s tuning to manual Check that the Modulation An alyzer s REMOTE and LISTEN annunciators are on and that the AUTO TUNING light is off Send the Clear message set ting the ModulationAnalyzer s tune mode back to automatic Check that the Modula...
Страница 179: ...t the HP 9835A and 9845A ABORT10 statement sends both the Abort message and the Local message Thus if the HP 9825A is being used the Modulation Analyzer s REMOTE annunciatorshould remain on If the HP 9835A or 9845A is being used the ModulationAnalyzer s REMOTE annunciator should turn off I Send the Local message HP 9825A only Address the Modulation An alyzer to talk and then store its output data ...
Страница 180: ...mode On the ModulationAnalyzer key in 61 3 and then press the SPCL key The display should show 1 O This indicates the ModulationAnalyzer is in serial poll mode indicated by the 1 Send the Abort message re moving the Modulation Ana lyzer from serial poll mode Check that the Modulation Ana lyzer s display shows 0 0 This in dicates the Modulation Analyzer properly left serial pollmode upon receivingt...
Страница 181: ...A used the ModulationAnalyzer s TALK annunci ator may be either on or off The con troller s display should read 0 00 HP 9825A or 0 HP 9835A and HP 9845A Send the Remote message Place the Modulation Analyzer in serial poll mode and address it to talk causing it to send the Status Byte message Display the value of V Check that the Modulation Analyzer s REMOTE annunciator is on Depend ing upon the vi...
Страница 182: ... enablinga Service Request to sent upon Instrument Error Makethe controller wait 2 seconds to allow time for the Modulation An alyzer message This step is not necessaryif sufficient time is allowed Readthe binary status of the con troller s HP IB interface and store the data in variable V in this step 7 is the interface s select code Display the value of the SRQ bit Check that the Modulation Analy...
Страница 183: ...ss the Modulation Analyzer to listen completing the Remote message then send a Data message placing the Modulation Analyzer in Hold mode Send the Trigger message Address the Modulation Analyzer to talk and store the data in variable V Displaythe value of V Check that both the Modulation Ana lyzer s REMOTE and TALK annunciators are on The controller s display should read 90000096000 00 HP 9825A or ...
Страница 184: ...ting an audio filter 0 selectingan audio range 0 using the Modulation Output and accounting for residual noise effects How To Find Information About a Specific Measurement Behind most tabs is a table of contents for that tabbed section Use this table of contents to find the Detailed Operating Instruction relevant to the measurement you are trying to make For example if lookingfor information about...
Страница 185: ...the rear panelRECORDER OUTPUT to improvethe accuracyof RF power measurements for the the HP Series 200 computers RF LEVEL MEASUREMENTS n n e d RF Level 3 91 IF Level 3 93 Selective Power Measurements Option Series 030 3 95 0 How to measure uncalibrated peak tuned RF power 0 How to measure the relative ALC level of AM demodulator 0 How to make selective off channel power or noise measurements Optio...
Страница 186: ...onse of the power sensor If no entry in the table directly corresponds to the frequency being measured the Modulation Analyzer derives a cal factor through linear interpolation using the nearest calibration points in the table on either side of the frequency being measured Up to sixteen frequency calibration factor pairs can be entered plus the reference cal factor You can enter review and manuall...
Страница 187: ...all other cal factors are relative to it 37 3 SPCL reference cal factor value printed on a label on the power sensor 9 6 CAL FACTOR Blue Key MHz Example Enter a reference cal factor of 98 5 into the Automatic Cal Factor table program codes 37 3SP 98 5CF Code 2 T Function Function Code 3 Enter each frequency cal factorpair 37 3 SPCL frequency value in MHz cal factor value CALFACTOR Blue Key MHz Rep...
Страница 188: ...n turned on allow at least a half hour continuous operation Connect the sensor between the Modulation Analyzer s SENSOR input and CALIBRATION RF POWER OUTPUT 7 Select ZERO If a power sensor is being used rather than a sensor module the CALIBRATE key light must be off for proper zeroing A sensor module has an internal switch that will automatically switch out any input signal After a few seconds 0 ...
Страница 189: ...yed from any Measurementmode 0 If no cal factor is entered the Modulation Analyzer uses the cal factor recalled last from the table as the manual entry 0 The manual cal factor remains in effect when the Modulation Analyzer is retuned 0 The automatic cal factor table is not affected by any manual cal factor entries 0 Can be keved onlv after selectina RF POWER 0 Can be keyed from any Measurementmode...
Страница 190: ... absolute power because the sensor type determines the sensitivity The chopper inthe power sensor convertsthe dc voltage generated by the power sensingelement to a 220 H z chopped ac signal The ac signal isthen amplifiedandrectified by a synchronousdetector whose configuration alternates between a non inverting and aninverting amplifier in step with the chopper CThe220 HzMultivibratoristhe sourcef...
Страница 191: ...s zero which may take several secondsto complete MODULATION ANALYZER 1 _ _ TO OTHER TUNED r m MEASUREMENT CIRCUITS ENSOR MODULE I I I INPUT RF ELEMENT CHOPPER DETECTOR DISPLAY RF POWER SENSING INPUI RF Power Block Diagram 7 MODULATION ANALYZER SENSOR MOOULE rTO OTHER I 1 CIRCUITS a m I P O W E R M E T E R 7 VOLTMETER SENSOR I I RESISTOP I I I I I I I I 1 I IOENTIFIER DISPLAY r t l I I RF INPUT J I...
Страница 192: ...ransfer function The ZERO key sets the zero crossing intercept and the SAVE CAL key sets the gain slope See the following figure The displayed power is given by the equation Pdi3 mPact b where Pdi3 is the Displayed Power Pactis the Actual Power b is the zero crossing and m is the slope The calibration routine forces b 0 and m 1 The followingexample shows the different responses that occur during c...
Страница 193: ... 0 or 32 1 is maintained through instrument power down 32 0 Power is displayed with the normal measurement resolution of 0 01 dB 32 1 Power is displayed with a measurement resolution better than 0 004 dF3 32 2 Displays 0 if the normal measurement resolution is enabled 32 0 SPCL and displays 1if a finer resolution is enabled 32 1 Error 15 Error 15 is displayed until all necessary cal factor entries...
Страница 194: ...l Oscillator LO value Referto frequency Ofset Control on page 3 225 for a procedure on entering an external LO value These two Automatic Calibration Factor tables are retained in the instrument s non volatile memory for use in all subsequent RF power measurements Every time you use the second table you must enter the external LO value User Built Sensor Module Any compatible power sensor can be con...
Страница 195: ...if the Modulation Analyzer is calibrated from the manual cal factor mode and then the Automatic Cal Factor mode is selected the instrument will continue to use the manually entered reference calibration factor until another SAVE CAL operation is initiated from the Automatic Calibration Factor mode Manual Cal Factors Manual Cal Factors are not frequency selective that is as frequency is changed the...
Страница 196: ...actor table Read Cal I Displays the calibration factor table currently being used by the Modulation Analyzer I Send I Loads the calibrationfactortable into the ModulationAnalyzerthat was enteredwith IEnter Tab 1e I PROCEDURE Enter the program into an HP series 200 controllerand connect the Modulation Analyzer via HP IB to the controller Connect the power sensor or sensor module to the Modulation A...
Страница 197: ...automatically select the value currently in the table Select Di I P1ay Tab 1e I to see the cal factors that you have entered Select ISend Analyzer Ito put those cal factors into the cal factor table in the Modulation To display the cal factors currently used by the Modulation Analyzer select I Read Cal I The controllerwill query the Modulation Analyzer and then display a list of frequency cal fact...
Страница 198: ...NEXT I GOTO Idle OFF KEY DISP New Cal Factor for REF position cal factor INPUT Cal 0 Freq 0 50 FOR 1 1 TO 10 PRINT ll ll PRINT Freq 1 Cal I Print out cal factors DISP New Frequency for number It I cal factor INPUT Freq 1 DISP New Cal Factor for number I I t frequency INPUT Cal 1 NEXT I GOTO Relabel CALL Clearscreen OUTPUT Hpib 41 SPM420 OUTPUT Hpib 37 4SP ENTER Hpib Pairs OUTPUT Hpib 37 5SPCF ENTE...
Страница 199: ...OR 1 1 TO 10 560 IMAGE 37 3SP 8D 2D MZ 4D 2D CF 570 OUTPUT Hpib USING 560 FreqU Cal I sending new c a l factors 580 NEXT I 590 BEEP 600 GOT0 Relabel 610 END 620 630 C1earscreen SUB Clearscreen 640 650 OUTPUT I USING I 660 DISP 670 SUBEND 3 84 RF Power Calibration Factor Entry Example Program ...
Страница 200: ...ge 3 71 PROCEDURE To make a broadband RF power measurement with an RF cable connected from the signal source to RF INPUT rather than a power sensor connection select RF POWER To make the measurement with the power sensor connected key in 35 0 SPCL HP IB PROGRAM CODES LIN LN LOG LG RF POWER M4 SPCL SP MEASUREMENT TECHNIQUE The broadband RF power at RF INPUT is detected by an RF peak detector The ou...
Страница 201: ...ratio referenceusing the RATIO key Refer to Ratio on page 3 215 Measuring RF Level on Signals with AM If the RF input signal has AM the peak envelope power is measured Previous Input High Pass Filter Selection The input high pass filter Special Function 3 remains inserted if previously selected Error 06 The maximum allowable input level is 1W into 500 Input levels greater than 1Wcause the overpowe...
Страница 202: ...nstrument as part of its measurement process The signal at the RECORDER OUTPUT then is a random series of pulses of varying level When Special Function 49 or 50 is not enabled the RECORDER OUTPUT is useful mostly as a troubleshooting aid However Special Functions 49 and 50 can set the internal voltmeter to suspend normal operation and to measure one input only The voltmeter s input is displayed an...
Страница 203: ...eguarded no ranging retuning error messages etc be sure the instrument is set up properly for worst case expected signal conditions 3 Key in the appropriate special function using the preceedingtable as a guide NOTE The measurement unit is volts Readings in excess of 4 are not valid Most measurements satisfy calibration requirements since the measured voltage is directly proportional to the normal...
Страница 204: ...easurement Key in 0 212 SPCL Key in 49 0 S 5 SPCL and record the voltmeter reading Vp Select SPCL twice Record the least significant digit the tenth digit on the display Rp This digit indicates the RF Power range Compute the RF power P in mW from the following formula v c V Rc vp V Rp CFC Vp VzRp CFp VC VzRp p X x 10 Rp Rc where CFc is the reference 50 MHz calibration factor from the chart on the ...
Страница 205: ...n enables the instrument to measure the level of frequencies that are drifting or to determine flatness as a function of carrier frequency This function is more sensitive than the RF Level Special Function 35 measurement mode PROCEDURE To make a tuned RF level measurement first tune the instrument to the input signal by selecting AUTOMATIC OPERATION Select TUNED RF LEVEL Shift RF POWER HP IB PROGR...
Страница 206: ...ULATION OUTPUT AUDIO INPUT is blanked AM OUTPUT and FM OUTPUT rear panel remain active during this measurement Relative Measurements If the tuned RF level is to be displayed relative to a reference enter the value as a ratio reference using the RATIO key Refer to Ratio on page 3 215 3 92 Tuned RF Level ...
Страница 207: ...el of the IF If the ALC loop is closed and there is sufficient IF signal available the ALC loop automatically adjusts the IF gain within the loop to force the detected IF to equal the ALC reference When the instrument is running in automatic operation the input attenuation is adjusted to keep the IF level within range of the ALC loop In the IF Level measurement mode the detected IF level is compar...
Страница 208: ...C loop is open Override this Error Message using Special Function 8 Refer to Error Message Disable Control on page 3 233 AM Depth When IF Level is Insufficient When operating with the AM ALC loop open or when the IF level is insufficient the displayed AM is proportional to the actual AM depth and the displayedIF level is proportional to the average carrier level The actual AM depth can be computed...
Страница 209: ...lled The bandwidthsof these IF filters match the requirements of specificindustry standardsfor measuring adjacent channel power The followingtable lists the optional filters and their bandwidths I Filters I ODtions I 12 5kHz Adjacent Channel Filter 25 kHz Adjacent Channel Filter 30 kHz CellularRadio Filter Option 032 Option 033 Option 035 I Carrier Noise Filter Option 037 All selective power measu...
Страница 210: ...O Input and LO Output Set the external LO source frequency to 455 kHz greater than the input frequency and its amplitude to 0 dBm Key in 2 3 1 SPCL to set the LO to external Setting the Reference 7 Select 24 1 SPCL to establish the IF reference value in volts 8 Select 24 2 SPCL to set the reference to 0 dB 9 Adjust the LO frequency until the maximum value is displayed The Modulation Analyzer s aut...
Страница 211: ...Bm a If using the internal LO on the Modulation Analyzer select 910 l kHz This tunes the Modulation Analyzer to the image frequency of the LO At this time the RF frequency display will not match the input frequency value 6 Key in 23 1 SPCL to set the LO to external Setting the Reference 7 Select 24 1 SPCL to establish the IF reference value in volts 8 Select 24 2 SPCLto set the reference to 0 dB 9...
Страница 212: ...vailable in LO Input and LO Output Set the external LO source frequency to 455 kHz greater than the input frequency and its amplitude to 0 dBm Key in 23 1 SPCL to set the LO to external Setting the Reference 7 Select 24 5 SPCL to establish the IF reference value in volts 8 Select 24 6 SPCL to set the reference to 0 dl3 9 Adjust the LO frequency until the maximum value is displayed The Modulation A...
Страница 213: ...wer measurements Dis plays the IF level in volts Establishes the level measured with 24 1 SPCL as the 0 dB reference Selectsa narrower bandwidthIFfilter than24 1 SPCL for adjacent channel power measurements Displays the IF level in volts Establishes the level measured with 24 3 SPCL as the 0 dB reference Selects a very narrow bandwith IF filter 2 5 kHz for the single sidebandnoisemeasurement Displ...
Страница 214: ...th the IF RMS Detector The in band IF level is defined as a ratio reference Next the frequency is offset either by tuning the RF input signal if this is possible or by tuning the LO as illustrated in b and c of the same figure Note that tuning is in opposite directions If it is desired to offset the IF to the upper skirt of the IF filter the RF frequency must be decreased or the LO frequencyincrea...
Страница 215: ...eqitency OJsct Amplitude b Frcqirency Oflsefby Increasing RF Signal Frcqirency Amplitude 455 kHz c Freqirency O j J s e fby Increasing LO Frequency Signal Tuning Illustrating Frequency Offsetting Selective Power Measurements Option 030 3 101 ...
Страница 216: ...pass filter An increase in the LO frequency either external or internal moves the IF signaldown the upper skirt Refer to Measurement Technique for an illustration of this The measurement specification may require that the frequency offset be made from the 6 dB corner frequencyof the IF bandpass filter Finding the IF Peak For maximum accuracy the frequency offset shouldbe relative to the frequency ...
Страница 217: ...Hz low pass filter and approximately 200 kHz when the instrument uses the wide 455 kHz bandpass filter At anyparticular input leveland front panelsetting the flatness of the IF OUTPUT asinput frequency varies is typically within k5 BLOCK DIAGRAM TO OTHER MEASUREMENT ITS I L IF Output Block Diagram COMMENTS Use the Modulation Analyzer as a Down Converter The Modulation Analyzer can be used as a hig...
Страница 218: ...ondingto the magnitude of external attenuation or gain expressed in dB 2 If the offset is gain rather than attenuation designate the value as negative by selecting the Blue Key and minus sign 1 key the decimal key No sign indication is necessary for entering attenuation 3 Select dB EXT ATTEN Blue Key LOG LIN To display the current offset in dB key in 25 2 SPCL To exit external attenuation select d...
Страница 219: ...NTS Inputloutput Status MODULATION OUTPUT AUDIO INPUT is blanked during most level measurements External Attenuation Value is Stored Through Other Measurement Selection If another Measurement mode is selected while the external attenuation function is enabled and a level Measurement mode is re entered the instrument automaticallyre enters the external attenuation mode with the previous offset 3 10...
Страница 220: ...ut of the Modulation Analyzer and the power sensor as measurements require NOTE An HP 478A i sa standard sensor but is not compatible with the Modulation Analyzer PROCEDURE The following procedure provides a few guidelines for setting up and operating a remotely controlled sensor module Connect the RF switch power sensor RF cable and Modulation Analyzer as shown in the BLOCK DIAGRAM Do not connect...
Страница 221: ... A REMOTECONTROL 1 J RFSWITCH 2 Block Diagram of Remote Control RF Switch I COMMENTS L J r T __I REMOTECONTROL I REMOTE CONTROL Outputs are Exclusive to Compatible Switches The rear panel REMOTE CONTROL outputs are not intended as general purposeswitchdrives The output should only be used with compatibleRF switches 3 108 Remote Control RF Switch ...
Страница 222: ...quency to which the instrument is tuned IF FREQUENCY IF Frequency 3 125 0 How to measure the instrument s IF frequency the down convertedRF input signal LO FREQUENCY LO Frequency 3 127 LO Input and LO Output 3 129 0 How to measure the instrument s local oscillator LO frequency 0 How to provide an input for an external LO 0 How to provide an output for the internal LO GENERAL FREQUENCY MEASUREMENT ...
Страница 223: ... instrument to the input signal select AUTOMATIC OPERATION or refer to RF Requency ltLning on page 3 115 to learn about more ways to tune the Modulation Analyzer Select FREQ Manual tuning will be necessarywhen measuring low levelsignals inputsless than 25 dBm from 150 kHz to 650 MHz or less than 20 dBm from 650 to 1300 MHz HP IB PROGRAM CODE FREQ M5 MEASUREMENT TECHNIQUE For input frequencies betw...
Страница 224: ...ction is in the automatic selection mode Special Function 8 0 very low level signals can be counted without generating error messages Error 03 for example However other Special F unction 8 codes enable error messages at much higher signal levels Refer to Error Message Disable Control on page 3 233 Centering the IF Does Not Affect Frequency Measurements It is importantto note that when FREQ is sele...
Страница 225: ...ent problem manually tune the LO so the passband for the down converted signal falls in an unoccupied region of the input spectrum This method is not a preferred way to make measurements but it might enable you to make some desired measurements Note that when using this method you should disable Error 01 by selecting 8 1 SPCL to prevent the Modulation Analyzer from trying to tune to a down convert...
Страница 226: ...Analyzer searches throughout its frequency range for an input signal If two input signals have similar power levels the higher frequency signal is usually selected The RF input signal s second and third harmonic levels must be at least 10 dB below the level of the fundamental and all other signals at the input must be at least 30 dB below the level of the desired signal Once tuned the LO is locked...
Страница 227: ...ith AUTOMATIC OPERATION or AUTO TUNING Blue Key 0 Select manual tuning with either MHz or one of the W z keys with or without a preceding 0 Select track mode with TRACK MODE Return from the track mode to the low noise mode by TRACK MODE numeric entry or with RANGE HOLD selecting TRACK MODE again Manual Tuning by Keyboard Entry To manually tune to a specific signal frequency enter the frequencyin M...
Страница 228: ...the last successfully tuned frequency plus or minus the frequency step Once a frequency step is entered on the keyboard refer to PROCEDURE pressing either of the kHz keys alone will change tuning by that step size until a new step frequencyis defined At power up the step size is zero HP IB RF frequencies can be changed in fundamental units Hz steps via the HP IB These steps are not possible from t...
Страница 229: ...a 1 5 MHz IF When the instrument is tuned to an image measurement errors may result with no Error Message displayed Theinput frequencymeasurementwill alwaysbe in error For FM and Mmeasurements the Peak and Peak functions are reversed One way to solve this problem is to step the tuning down by twice the IF frequency or let the instrument automatically tune The followingIF response plot illustrates ...
Страница 230: ...ise LO mode Respondingto Frequency Changes Using the automatic tune mode the Modulation Analyzer might not retune when the frequency changes but its spectrum still has sufficient power within the tuned passband of the Modulation Analyzer s RF INPUT It will appear that the carrier simply changed its level If the instrument does not retune frequency and level measurement results might not be as expe...
Страница 231: ...e to the signal then select the MHz key to prevent retuning Select FREQ ERROR Shift FREQ to display the frequency error As the signal drifts the display indicates the magnitude and direction of the drift To make a frequencycomparison enter the reference frequency in MHz on the keyboard then select MHz Select FREQ ERROR to display the difference frequency The number is negative if the signal freque...
Страница 232: ...frequency 455 kHz or 1 5 MHz to determine the frequencyerror 0 When the input signal is less than 2 5 MHz the input signal is passed directlyinto the IF without down conversion When the signal is first located the frequency is counted When the FREQ ERROR key is selected this first countedfrequencybecomes the reference Subsequentfrequency counts are subtracted from this reference and the results ar...
Страница 233: ...mage Passband Distorts Measurements When tuning manually it is possible to accidentally adjust the LO so that the input falls in the image passband for example when using the kHz fl and kHz keys Frequency error measurements are inaccurate when the input image enters the IF passband Refer to RF frequency Zhing on page 3 115 for an illustration of the image passbands Changing Resolution Normally the...
Страница 234: ...convertedto a 1 5 MHz IF Notethat specialh c t i o n 3 can be used to select the 455 kHz IF Refer to Filters RF and IF on page 3 229 Special hnction 34 0 enables the Modulation Analyzer to measure and display the IF frequency for the signal being measured PROCEDURE To measure the IF frequency key in 34 0 SPCL MEASUREMENT TECHNIQUE The IF signal generatedwhen the Local Oscillator and the RF input s...
Страница 235: ...ilterselectionisdependenton the selectedIFFrequency RefertoFilters RF and IFon page 3 229 When using the 455 kHz IF on input signals with frequencies greater than 300 MHz incidental AM that is AM due to FM increases substantially RF Input Frequency Calculation The Modulation Analyzer determinesthe frequency of the RF input signal by counting the frequencies of both the IF and LO and calculatingthe...
Страница 236: ...n IF Yes 455 kHz Keyed In IF No 1 5 MHz 101 5 MHz PROCEDURE To measure the LO frequency key in 33 0 SPCL MEASUREMENT TECHNIQUE The LO frequencyis essentially measured directly by the counter The frequencythat the LO is tuned to depends on 1 whether automatic tuning or manual tuning is being used 2 whether the RF input signal is being down converted and 3 which IF is being used The following table ...
Страница 237: ...e Special Function 7 Refer to RF frequency Resolution on page 3 131 Counter accuracy is the reference accuracy f 3 counts LO Does Not Phase Lock to INPUT In general LO tuning is never exact but is close enough to give calibratedmeasurements The LO does not phase lock to the RF input signal LO Frequency for INPUT Less Than 2 5 MHz When the RF input signal is less than 2 5 MHz the LO frequency is se...
Страница 238: ...local oscillator LO signal is routed through the rear panel LO OUTPUT and LO INPUT connectors The range of the LO signal i s 1 27 MHz t o 1301 5 MHz at approximately0 a m Both connectors are 500 ac coupled Type N connectors NOTE The rear panel u OUTPUT must be connected to the rear panel u INPUT for normal Modulation Analyzer operation that wes the internal local oscillator BLOCK DIAGRAM ATTENUATO...
Страница 239: ...O from continuously 3 Add the IF frequency to the frequencyto which the Modulation Analyzer is to be tuned and set 4 Adjust the external LO to 0 dBm and connect it to the LO INPUT tuning the external LO to that frequency COMMENTS Using the LO OUTPUT LO tuning is not exact The instrument tunes the LO only close enough to make calibrated measurements Using the LO INPUT To tune to inputs below 2 5 MH...
Страница 240: ...on mode key in the corresponding Special Function code then SPCL Note that with finer resolution measurement time increases 7 0 Automatic selection 7 1 Resolution of 10 Hz 7 2 Resolution of 100 Hz 7 3 Resolution of 1kHz 7 4 Applies to RF Frequency measurements only other measurements treat 7 4 as 7 1 Resolution of 0 1 Hz for input signals less than 10 1 MHz resolution of 1 H z for signals from 10 ...
Страница 241: ...ebursts QM QM 3 169 0 How to measure QM deviation AUDIO DETECTORS Audio Detectors 3 173 Audio Detector Response 3 177 0 How to select the peak average and rms audio detectors 0 How to trade off readability of noisy signals for measurement time GENERAL MODULATION MEASUREMENT FUNCTIONS Audio Filters 3 179 0 How to select the high pass and low pass noise filters which filter the demodulated signal Au...
Страница 242: ...10 to 1300 MHz 1 5 MHz IF only The corresponding 3 dB audio bandwidths are approximately0 5 Hz to 15 kHz for carriers 10 MHz and below or with the 455 kHz IF and approximately0 5 Hz to 260 kHz for carriers from 10 to 1300 MHz 1 5 MHz IF only Special Function 6 1 will modify the lower frequency Modulation depths to 99 can be measured The demodulated signal s frequency and distortion can also be mea...
Страница 243: ... measures AM as a ratio of the demodulated audio signal level to the average tuned carrier level An automatic level control ALC loopwithin the AM Demodulator holdsthe carrier level constant so that the percent AM is proportional to the peak amplitude of the demodulated audio output This audio output is then filtered audio detected and displayed as I AM The demodulated AM is available at MODULATION...
Страница 244: ... ranges that can be set Automatic Filter Selection When operatingabove 2 5 MHz while using the 455 kHz IF the upper limit of the demodulatedsignals modulation rate is that of the 2 0 kHz LP Filter The 15 kHz LP Filter is automatically selected when operating below 10 MHz or whenever the 455 kHz IF is selected However this filter may be overriddenby selectinganother LP Filter The lower limit of the...
Страница 245: ...its measuring absolute changes in depth without regard to changes in carrier level a feature that is useful in characterizingamplitude modulators PROCEDURE The instrument normally operates with a slow AM ALC response time To change the response time or to disable the ALC enter the corresponding Special b c t i o n code then select SPCL AM ALC Response Special Function Code I 6 0 SPCL I 6 0SP I Slo...
Страница 246: ...o the RF INPUT with a 50R cable or a sensor 2 Select CALIBRATE After severalseconds the AM calibration factoris displayedin and stored The instrument displays 100 00 if no error is measured A display of 100 17 means the AM demodulator in the Modulation Analyzer is reading 0 17 high As long as the CALIBRATE key light is on and the cable is connected calibration repeats and the AM calibration factor...
Страница 247: ...xcludingnoise Select 1 3 1 SPCL for both instruments Record the value that appears on the display of the RF signal analyzer If display jitter makes readings difficult select 5 1 SPCL The displayed value is the weighted peak residual AM depth of the calibrator s unmodulated output as demodulated by the RF signal analyzer Select 13 2 SPCL for both instruments Record the value that appears on the dis...
Страница 248: ...t is displayed Subsequent updates occur approximately every 17 seconds Correcting Measurements with the AM Calibration Factor Self Calibrated When the calibration factor is enabled the AM depth measurement is alwaysa corrected measurement If CAL FACTOR Blue Key MHz is selected and the AM calibration factor is enabled the AM calibration factor is displayed If CALFACTOR BlueKey MHz is selected and t...
Страница 249: ...ic measurements with the demodulated AM toggledmeasurements and computes its accuracy error as follows Demodulated A M Demodulated Residual A M Computed A M A M CalibrationFactor x 100 All segments of the calibration are carefully monitored If any segment is out of limits the calibration is aborted and Error 08 is displayed MODULATOR A BUFFER A Simplified Block Diagram of the AM Calibrator COMMENT...
Страница 250: ...andard must have demodulationand audio processingcircuits which preserve the full fidelity of the waveform Automatic AM Ranging When used to calibrate an RF signal analyzer Special Functions 1 3 1 and 1 3 2 set the AM modulation range to that of 0 to 100 Special Function 2 1 Upon exiting the AM Calibrator Special Function the audio ranging is not returned to automatic but remains fixed thus leavin...
Страница 251: ...elationship between 9 6 AM and the signal levels at AM OUTPUT is A M vpk xlW IVdc Voff I where Vpk is the peak of the ac component Vdc is the t o t a ldc component and Voffis the dc offset voltage When the AM ALC is on the dc level at AM OUTPUT is held constant thus A M K x Vpk where 100 Vdc Voff K When the AM ALC is turned off Special F unction 6 2 the dc voltage at AM OUTPUT varies with the sign...
Страница 252: ...e dc voltage at AM OUTPUT When low AM rates are used it is easiest to measure the dc voltage at AM OUTPUT before the modulation is applied For this example assume the voltmeter reads 0 46 Vdc Measure the peak ac voltage at AM OUTPUT for low rates an oscilloscopemay be necessary For this example assume 0 02 Vpk was measured on an oscilloscope The AM is Vpk x 100 0 02x 100 20 AM A M lVdc off1 l 4 46...
Страница 253: ...IF component which is greatest when operating at a carrier frequency of 150 kHz Peak Detector Measurements of AM Output The accuracy of measurements made on the AM OUTPUT signal could be degraded if RF level measurementsare made using the F W peak detector SpecialFunction 35 0 AM Output 3 149 ...
Страница 254: ... carriers 10 MHz and below or with the 455 kHz IF and approximately 0 2 Hz to 260 kHz for carriers from 10 to 1300 MHz 1 5MHz IF only Peak deviations up to 40 kHz can be measured on carriers below 10 MHz and peak deviations up to 400 kHz can be measured on carriers above 10 MHz The demodulated signal s frequency and distortion can also be measured Refer to Audio Measure ments on page 3 197 PROCEDU...
Страница 255: ... Pk Avg RMS Pk Avg Pk Avg RMS Pk AVQ RMS Pk Avg R M S Pk Avg RMS I I 0 1 i eIec tion 100 10 1 0 1 0 01 _____ With750 ps de emphasis pre display only To filterthe demodulatedsignal pressthe appropriate filterkeys RefertoAudioFilters on page 3 179 for more information about filters If de emphasis equalization is desired select the appropriate time constant and displayplacement Referto FM De emphasis...
Страница 256: ...FM signal always passes through the FM de emphasis network before it appears at the output of MODULATION OUTPUT AUDIO INPUT FM Measurement Block Diagram COMMENTS Input Output Status The demodulated FM is present at MODULATION OUTPUT AUDIO INPUT unless AUDIO INPUT has been selected The demodulated FM is usually present at the rear panel FM OUTPUT connector If the RF input signal drops too low for a...
Страница 257: ...FM with a sensitivity of 0 01 Vpk MHz 400kHz peak deviation range is available at MODULATION OUTPUT AUDIO INPUT The instrument does not autorangeto more sensitive ranges because the FrequencyMeasurementmode has been automatically selected which automatically disables Error 04 audio circuits overdriven When Error 04 is disabled the instrument only autoranges to less sensitive audio ranges Increased...
Страница 258: ...T to the RF INPUT with a 50Qcable or a sensor 2 Press the CALIBRATE key After several seconds the FM calibration factor is displayed in The instrument displays 100 00 if no error is measured A display of 100 17 means the FM demodulator in the Modulation Analyzer is reading 0 17 high As long as the CALIBRATE key light is on and the cable is connected calibration repeats and the FM calibration facto...
Страница 259: ...zer Ifdisplayjitter makes readings difficult key in 5 1 SPCL The displayedvalue is the weighted peak residual FM deviation of the calibrator s unmodulatedoutput as demodulated by the RF signal analyzer 4 Key in 12 2 SPCL for both instruments Record the value that appears on the display of the RF signal analyzer If display jitter makes readings difficult select 5 1 SPCL The displayed value is the d...
Страница 260: ... Factor Self Calibrated When the calibration factor is enabled the FM deviation measurement is always a corrected measurement If CAL FACTOR is selected and the FM calibration factor is enabled the FM calibration factor is displayed If CAL FACTOR is selected and the FM calibration factor is disabled 100 is displayed Note the resolution of 1 Calibrating Another RF Signal Analyzer The Modulation Anal...
Страница 261: ...sed 100 00 is used as the default calibration factor Updating the FM Calibration Factor Whenever FM calibration is performed the instrument updates the stored FM calibration factor Special Function Cancellation Performing calibration cancelsmost Special finctions When Using the FM Calibrator to Calibrate Other Signal Analyzers The modulation waveform of the FM Calibrator is a rounded trapezoid An ...
Страница 262: ...between the time constant r0 and the 3dJ3 comer frequency fo is fo 1 The 3dB comer frequencies of the de emphasis equalizers typicallyaccurate to f3 arelisted in the followingtable I FM De emphasis I Time Constant PS 3 dB Frequency Hz 25 50 75 750 6366 3183 2122 212 2 PROCEDURE To add de emphasisto the demodulated FM select the key correspondingto the desired time constant UnlessAUDIO INPUT has be...
Страница 263: ... will affect the output signal at MODULATION OUTPUT AUDIO INPUT and can be placed before the audio detector and display Refer to the block diagram in FM De emphasishas no affect on the rear panel FM Output When Measuring Low Deviation FM When 750 ps de emphasis is selected FM sensitivity at the MODULATION OUTPUT AUDIO INPUT is increased by a factor of ten The range of deviation measurements is res...
Страница 264: ...remember when programming the instrument via HP IB Considerations When Using the RMS Detector During FM measurements if the RMS detector is selected Blue Key AVG FM de emphasis pre display is automatically selected Pre display must turn on at this time due to circuit configuration of the Modulation Analyzer When pre display is selectedthis way it will not turn offautomaticallywhen another detector...
Страница 265: ... OUTPUT can be calculatedas follows K FREQERROR 1000 Vdc V ff where Vdc representation of the dc voltage at FM OUTPUT volts V ff representation of the dc offset voltage for the IF used volts K the FM sensitivity in mV kHz or V MHz and FREQ ERROR the kHz error displayed when FREQ ERROR is selected Measure V ff when the frequency error is 0 kHz The sensitivity can be measured using the followingproc...
Страница 266: ...50 kHz Inverted AC Output Component Note that the sense of the ac output component correspondingto the demodulated FM is inverted for carriers above 2 5 MHz Accuracy of Output During RF Level Measurements When RF Level measurements Special h c t i o n 35 are made automatic selection of RF input attenuation overrides any manual settings that might have been selected with Special Function 1 The sele...
Страница 267: ...ed as a tone burst receiver This function inserts a user selectable delay between the instant the instrument senses an RF signal at its RF INPUT and the time when it turns on the output of MODULATION OUTPUT AUDIO INPUT When an external counter is connected to this output the squelch tone will reach the counter only when a valid measurement can be made The time delay is selectable from 1through 99 ...
Страница 268: ...key is pressed 18 is displayed NN is the delay in milliseconds If no RF is at the RF INPUT connector two dashes are displayed COMMENTS Suggested Use of Maximum Delay When using the Tone Burst Receiver Special Function use the 99 ms delay for best results Shorter delays require very careful setup since with no input the high gain IF Amplifier and Limiters tune the noise to an average frequency ofte...
Страница 269: ...Burst Frequency Cannot Be Measured The audio frequencymeasurement mode cannot be used to measure the frequency of the tone burst MBut Not AM This feature works also with the OM measurementmode but not AM Tone BurstReceiver 3 167 ...
Страница 270: ...es from 200 Hz to 20 kHz however the low frequency 3 dB limit is typically 7 H z The following figure shows the display resolution for different combinations of peak phase deviation and modulation rate RESOLUTION 0 001 RADIAN RESOLUTION 200 Hz 500 Hz 1 kHz 2 kHz 5 kHz 10 kHz 20 kHz MODULATION RATE PROCEDURE To make a OM measurement first tune the instrument to the input signal by selectingAUTOMATI...
Страница 271: ... 1 0 01 0 1 0 1 0 01 Automatic Selection 2 0 SPCL 10 4 2 4 SPCL Pk Avg 2 4 SPCL 54 540 Pk Avg RMS 2 1 SPCL Pk Avg RMS 2 2 SPCL 1400 Pk Avg RMS 2 3 SPCL To filterthe demodulated signal selectthe appropriate filterkeys Referto Audio Filterson page 3 179 for more information about filters EXAMPLE Tomeasurethe positive peak phase deviationof a signal in a 50Hz to 15kHzpost detection bandwidth program ...
Страница 272: ...asure ments which begins on page 3 197 Relative Measurements If Mdeviation is to be displayed relative to a reference enter the value as a ratio reference using the RATIO key Refer to Ratio on page 3 215 Peak Detector The PEAK detector always detects the upward carrier phase excursion while the PEAK detector always detects the downward carrier phase excursion The PEAK 2 detector sums the upward an...
Страница 273: ... and may cause inaccurate measurement of QM deviation or Error 05 FM squelched Input Output Status When QM is selected the signal at the rear panel FM OUTPUT still represents demodulated FM not QM Increased Accuracy Accuracy of QM readings may be improved by taking into account the effects of residual noise Refer to Residual Noise Effectson page 3 191 Phase Deviation in Degrees To display phase de...
Страница 274: ...k detector modes This mode enables the instrument to hold and display indefinitely the largest peak detected This feature is useful for capturing the peak maximum of a modulation transient Average detection selects an average respondingdetector that is calibrated to read the rms value of a sinewave True RMS detection selects a true rms detector to measure audio signals Also noise and residual meas...
Страница 275: ...P IB PROGRAM CODES Function PEAK PEAK PEAK HOLD AVG RMS PEAK212 Program Code D1 D2 D3 D4 D8 D9 Input Output Status The signal at MODULATION OUTPUT AUDIO INPUT AM OUTPUT or FM OUTPUT is not affected by the DETECTOR keys True RMS Detector Only the true rms detector can be used for external audio level Special h c t i o n 30 and for audio distortion measurement and SINAD Special k c t i o n 29 HP IB ...
Страница 276: ... switchtothe peak detector modepreviously selected If PEAK HOLD is selectedwhile the peak average PEAKf 2 mode is active the detector reverts to PEAK with PEAK HOLD HP IB In remote operation new peak hold cycles can only be initiated by code D3 Thus if the instrument is in HP IB Hold mode code Tl issue code D 3 to initiate a peak hold cycle Although the display cannot be updated when in HP IB Hold...
Страница 277: ...ime improvesmeasurement readability on unstableor noisy signalswheneverdisplay jitter is excessive PROCEDURE The Modulation Analyzer is normally set for fast response To change from fast to slow or vice versa enter the corresponding Special Function code then select SPCL COMMENTS Default Condition When the instrument is first turned on or when Automatic Operation or Instrument Preset is selected t...
Страница 278: ...They also provide pre defined bandwidths for residual noise measurements PROCEDURE Insert the desired demodulated signal filter by selecting the appropriate keys Only one high pass and one low passfilter can be inserted at once To remove a filter select the key again To select a different filter press the key correspondingto the desired filter HP IB codes for the various filter keys listedin the f...
Страница 279: ... inserted automatically When the 455 kHz IF is used or when the RF input is less than 2 5 MHz the 15kHz low passfilter is inserted unless another low pass filter has been selected The ALL OFF 200 kHz low pass filtering cannot be selected The 15 kHz low pass filter selected when operating with the 455 kHz IF is automatically turned off when the 1 5 MHz IF is selected Bandwidth Limitations With no f...
Страница 280: ...Low Pass Five pole Chebyshev 1 flat to 10 kHz 20 kHz Low Pass Nine pole Bessel 1 flat to 10 kHz When used with square wave modulation this filter typically overshoots 1 This filter s 3 dB point is typically 110 kHz Filter Selection Does Not Affect Some Measurements External Audio level distortion and SINAD measurements are unaffected by the audio filters Recommended Filter Selection Because of the...
Страница 281: ...e appropriate for the desired measurement To set the audio range manually use Special h c t i o n 2 2 4 SPCL 2 4 SPCL PROCEDURE 2 4SP 0 001 0 1 2 4SP 0 01 0 1 To set the audio range or to re enter the automatic selection mode select the corresponding Special Function code 2 1 SPCL 2 2 SPCL 2 3 SPCL or Audio Range Available for AM 2 1SP 0 01 0 1 2 2SP 2 3SP or 0 1 0 01 Modulation Range Peak Oh L Au...
Страница 282: ... 540 1400 I Automatic Selection RMS RMS Pk Avg Pk Avg RMS Pk Avg Pk Avg RMS Pk Avg RMS Pk Avg RMS Pk Avg RMS 2 3SPCL 1 2 3SP I 100 MODULATION OUTPUT Sensitivity Vac O o Hz election 4 0 1 I 0 01 1 I With 750 ps de emphasis pre display only I Modulation Range Peak2rad dev Automatic 10 4 54 540 I 5400 Audio Range Available for cPM Special Function Code Detector Selected Selection 2 0 SPCL RMS 2 4 SPC...
Страница 283: ...ed The output of the MODULATION OUTPUT AUDIO INPUT will probably be clipped Depending on the audio filteringand detector in use Error 04 may not be generated at exactly the nominal values listed in the tables above Disabling Error 04 Inhibits Audio Autoranging When Error 04 is disabled refer to Error Message Disable Control on page 3 233 the Modulation Analyzer automatically ranges to a less sensi...
Страница 284: ... in 600R DESCRIPTION ModulationOutput MODULATION OUTPUT AUDIO INPUT provides a calibrated output for signals demodulated by the Modulation Analyzer The output signal available at the connector usually corresponds to the current modulation measurement The output is dc coupled and has a 600Q output impedance into a BNC female connector Audio Input The input at MODULATION OUTPUT AUDIO INPUT also prov...
Страница 285: ...ts the last selected modulation measurement Blanks output turns off all ModulationOutput Audio is Audio Input keylights 1 1 Selects the demodulatedAM signal unless AUDIO INPUT is selected AUDIO DISTN on AUDIO INPUT key selection 1AUTOMATIC OPERATION I ISelectsthe last selectedmodualtion measurement FM FREQ FREQ ERROR INSTR PRESET w RF POWER ITUNED RF LEVEL Selectsthe demodulated FM signal unlessAU...
Страница 286: ...anual setting of the audio range The following table examines this relationship Refer to Audio Range on page 3 183 for more information on modulation ranges FM 4M Display Resolution Modulation output O O Vac O o Hz Sensitivity DispIay Resolution Modulation output Resolution Sensitivity Display Modulation output Sensitivity mVac Hz radians mVac radian 0 001 0 01 100 0 0001 10 0 1 0 1 10 0 001 1 I A...
Страница 287: ...This is because at power up FREQ is selected Thus Error 04 audio circuits overdriven is automatically disabled When Error 04 is disabled only autoranging to less sensitive audio ranges is allowed Safeguarding Output Signal When Errors 01 through 04 are always enabled via Special h c t i o n 8 8 the output signal at MOD ULATION OUTPUT AUDIO INPUT is entirely safeguarded Under this condition the ins...
Страница 288: ...k modulation measurement The displayedmeasurement result will 2 Press the Range Hold key to prevent autoranging If filtering and or de emphasis was used in 3 Remove the modulation from the signal and measure the remaining peak residualnoise Npk on 4 Select AVG Measure the average residual noise Nav 5 Compute include the signal plus its noise s N p k step 1 make a l l the following measurements wit...
Страница 289: ...o the Modulation Analyzer The modulation rate is 1 kHz and the peak modulation is to be measured in a 15kHz post detection bandwidth To measure the peak AM depth and correct for the effects of residual noise on the modulation 1 Measure the peak modulation depth S N pk LOCAL keystrokes program codes AU M1 D 1 1 2 Measurement L T LFilter Detector For the purposes of subsequent calculations assume th...
Страница 290: ...play 4 Measure the average residual modulation DETECTOR r R m s C A L 1 e 7 Detector For the purposes of subsequent calculations assume the displayed average residual AM is 0 02 5 Compute 6 Compute s k N p k 30 80 NPk 0 07 440 7 Use the nomograph to find N For the purposes of these calculations assume N is 26 Compute Spk S N p k Npk N 30 80 0 07 0 26 30 78 NOTE This correction factor of 0 1 of the...
Страница 291: ...Operation Model 8901B E To Voltmeter I 1 Simplified Diagram of the Modulation Analyzer s Peak Detector 3 194 Residual Noise Effects ...
Страница 292: ...oise for example line relatednoise has repeating peaks and thus does not fall within the statistical model used to derive the nomograph given in the procedure A noise peak to noise average ratio Npk Nav greater than 4 4 is a strong indication of a periodic component in the residual noise Use Range Hold During Measurement Both the modulation and the noise measurements used with the nomograph should...
Страница 293: ...an external audio frequency Audio Distortion and Level 3 201 0 How to measure audio distortion onlyat 400 Hz or 1 kHz on either an internallydemodulatedor an 0 How to measure the level of external audio input 0 How to measure SINAD onlyat 400 Hz or 1 kHz on either an internallydemodulatedor an external external audio input SINAD 3 203 audio input 3 197 ...
Страница 294: ...250 kHz The input signal should not exceed 4 Vrms The input impedance is approximately 100 kn HP IB PROGRAM CODES AUDIO FREQ S1 AUDIO INPUT A1 MEASUREMENTTECHNIQUE The audio frequencyis measuredby a reciprocal typecounter The input can be either the demodulated FtF at the INPUT or an external audio input at the MODULATION OUTPUT AUDIO INPUT The Modulation Analyzer gates its internal 10 MHz time ba...
Страница 295: ...measurements this special function enablesa resolution of 0 001 dB instead of the normally displayed resolution of 0 01 dB The selection of Specialb c t i o n 32 0or 32 1 i s maintained through instrument power down 3 2 0 Audio frequency is displayed with the normal resolution of 1 H z for frequencies from 100 to 3 2 1 Audio frequency i s displayed with a resolution of 0 1 Hz for frequencies from ...
Страница 296: ...lated audio signal select AUDIO DISTN Shift FM To measure distortion on an external audio signal applied to the MODULATION OUTPUT AUDIO INPUT select AUDIO DISTN Shift FM and AUDIO INPUT Only the true rms detector can be used for these measurements To change the measurement bandwidth of the internally demodulated audio signal Select the desired filter keys Refer to Audio Filters on page 3 179 If me...
Страница 297: ...stortion and Level Block Diagram COMMENTS Audio Level Measurement in Watts Selection of watts as the unit for audio level measurements results in an error Automatic Selection of RMS and PRE DISPLAY Selection of an audio distortion or level measurement automaticallyselects the true rms audio detector and sets FM de emphasisto the pre display mode Refer to FM De emphis on page 3 159 The SINAD measur...
Страница 298: ...demodulated audio signal select 29 0 SPCL To measure SINAD on an external audio signal applied to the MODULATION OUTPUT AUDIO INPUT select 29 0 SPCL and AUDIO INPUT Only the true rms detector can be used for this measurement To change the measurement bandwidth of the internally demodulated audio signal select the desired filter keys Refer to Audio Filters on page 3 179 If measurements are to be ma...
Страница 299: ...sponse time can be selected with Special Function 5 1 The slow response time improves measurement readability on unstable or noisy signalswhenever display jitter is excessive The slow response time for SINAD is not available with firmware date codes 234 1985 and below To display the firmware date code select 42 0 SPCL To order a ROM set that contains this special function contact the nearest HP sa...
Страница 300: ...How to access the instrument s 8 storage registers Storemecall 3 223 FUNCTIONS THAT INCREASE MEASUREMENT CAPABILITIES Frequency OffsetControl 3 225 Filters RF and IF 3 229 0 How to extend the frequency range of the instrument into the microwave region using an external down converter 0 How to insert the RF high pass filter in the RF signal path to eliminate interfering 0 How to select the frequenc...
Страница 301: ... RATIO RF level and modulation related calibration factors remain intact Limit settings Special Fbnction 14 and Frequency Offset Control Special Fbnction 27 are also not affected PROCEDURE To enter the Automatic Operation mode select Automatic Operation The instrument will immediately re tune to the input signal and make the measurement selected HP IB PROGRAM CODE AUTOMATIC OPERATION AU COMMENTS I...
Страница 302: ...but bypasses the internal checks The Modulation Analyzer contains a battery back up to its internal memory which makes part of the memory non volatile after the power has been switched off powered down even if the power cord is unplugged Information retained after power down 0 The 8 instrument states stored in the Store Recall registers 0 For RF Power a One set of zero and calibration SAVECAL data...
Страница 303: ... Measurement Conditions Tuning Measurement Mode IF Fkequency Modulation Output Audio Input High Pass Filter Low PassFilter Calibration Mode Special finctions HP IB Special Functions 1 10 11Previous Ratio Ratio Reference 14 Limit Upper Limit Lower Limit Upper Lower Limit Code 16AM Calibration Factors 17FM Calibration Factors 22 Service Request Status Byte 25 External Attenuation 27 Frequency Offset...
Страница 304: ...all of the instrument states stored through power down may be non existent If this information is lost a The Recall function reverts to the Instrument Preset state b The RF Power measurement will 1 display Error 15 2 light the UNCAL and RECAL annunciators and 3 use the default zero and calibrationfactors The RF power calibration factors must be re entered c AM and FM calibration factorswillbe 100 ...
Страница 305: ...ted by Range Hold High passand Low pass Filters FM De emphasis Measurement Detectors and Display Special Functions prefixed 1through 10that are already manually set are unaffected The table below summarizes the effect of the Range Hold feature Effectof RANGE HOLD on Functions Special Function Prefix MeasurementFunction Holds setting Holds setting Holds setting No effect No effect Holds setting No ...
Страница 306: ...by manually entering the desired setting For example the Range Hold function places the instrument in the manual tune mode select AUTO TUNING Blue Key TRACK MODE to re enter the automatic tuning mode Similarly Special Functionscan be used to set other functions or selectively return them to automatic operation 3 214 Range Hold ...
Страница 307: ...when the ratio function is used annunciator REL is added to the display All modulation and all frequency measurement results cannot be displayed with absolute logarithmic units even though they can be displayed in relative logarithmic units The LOG LIN key is ignored The Ratio function can be used with the following measurements AM SINAD 29 0 SPCL FM Ext Audio RMS Level 30 0 SPCL M LO Frequency 33...
Страница 308: ...tion Analyzer uses the previousratio reference regardlessof what Measurement the instrument was in when the ratio reference was entered and regardless of the current Measurement mode To display the ratio or previous ratio reference key in 11 2 SPCL r D y E l Y Display The displayed measurementresult is 100 REL if linear units are selectedor 0 dB REL if logarithmic units are selected The display wi...
Страница 309: ...ly displayedmeasurement resultasthe ratio reference that result actuallybecomes the reference The only way to read this reference then is to display it via SpecialE unction 11 2 Display Flicker Since displayed measurement results are computed from the actual physical measurements least significant digit flicker in the physical measurement can often lead to larger apparent flicker in the displayed ...
Страница 310: ...t Refer to R F Bequency Zbning on page 3 115 for a discussion of track mode tuning Setting Measurement Limits The ratio reference can also be entered as a limit reference Refer to L i m i t on page 3 219 Common Ratio Measurements The followinglist provides some useful references for common ratio measurements 0 To display broadcast FM deviation relative to the common standard of 75 kHz use 75 and 0...
Страница 311: ...t mode If after setting limits another Measurement mode is selected the Limit feature is deactivated but it is restored automaticallywhen the former Measurement mode is re entered Both limit references can be displayed cleared and restored the status of the Limit function can be displayed and the Measurement modes for which the limits were set can be displayed PROCEDURE To establish a ratio refere...
Страница 312: ...lay limit status in the format Lower Upper where O disabled and l enabled I To display the limited measurement mode To determine the Measurement mode in which a lower or upper limit is in effect select 14 7 SPCL or 14 8 SPCL respectively The displayed code represents the measurement in which the limit is in effect These codes are indexed in the following table Display 0 000 0 001 0 002 0 003 0 005...
Страница 313: ...pon the displayed number Thus if the Ratio feature is enabled simultaneouslywith the Limit feature the limit test is still based on the measurement result not the computed ratio Limits cannot be set in terms of relative measurement results Importanceof Key Sequence If SpecialFunction 14 1 or 14 2 is initiated with no previous numeric value the ratio referencebecomes the entered value The desired l...
Страница 314: ... Blue Key 7 Then key in a register number 1 through 8 To recall a previously stored instrument state select RECALL Blue Key 8 Then key in the desired register number 1 through 8 HP IB PROGRAM CODES RECALL RC STORE TR COMMENTS Regarding storage of RF power calibration factors 0 The current reference calibration factor and the frequency calibration fac x pair can be stored 0 Manual calibration facto...
Страница 315: ...tors in the Frequency Offset mode Frequency entries can range from 0 to 110 GHz Refer to RF Power on page 3 71 for a procedure for entering calibration factors A rear panel FREQ OFST TTL OUT connector can indicate to external circuits whether the Modulation Analyzer is in the Frequency Offset mode and whether the LO is above or below 18 GHz Use this feature to control external RF switches to route...
Страница 316: ...n 1300 MHz of the external LO to be within the measurement range of the Modulation Analyzer The LO frequency is manually entered by the operator using Special hnction 27 3 The Modulation Analyzer thereafter uses that LO frequencyto compute the microwave input signal frequency regardless of the actual frequencyof the LO If tuning is in the automatic mode the Modulation Analyzer computes and display...
Страница 317: ...r MEASUREMENTTECHNIQUE is a difference Peak and Peak Functions Reversed When FM or bM measurementsare made the Peak and Peak functions are reversedwhenever the external LO frequency is less than the microwave input frequency HP IB Service Request Mask Using Special hnction 22 bit weight 16 the Modulation Analyzer can be unmasked to output a Service Request whenever the Fkequency Offsetmode changes...
Страница 318: ... An IF of 455 kHz can be manually selected For signals between 2 5 MHz and 10 MHz the IF is 455 kHz Below 2 5 MHz the signal is passed directly into the IF without down conversion unlessthe 455 kHz IF has been manually selected IF filters determine the frequency response of each IF When the 1 5 MHz IF i s selected the IF frequencyresponse is determined by the 2 5 MHz Low Pass LP Filter When the 45...
Страница 319: ...n mode Automatic Retuning When a new IF is selected the instrument immediately retunes Increased Sensitivity and Selectivity Many measurements can typically be made on very low level signals Using the narrow bandwidth of the 455 kHz IF for signal frequencies less than 2 5 MHz but in the manual down convert mode or greater than 10 MHz increases the sensitivity and selectivity of the Modulation Anal...
Страница 320: ...e or to enter an automatic selection mode key in the correspondingspecial function code then select SPCL r 1 3 SPCL T 1 3SP 1 COMMENTS Default Condition When the ModulationAnalyzeris first powered up or when Automatic Operationor Instrument Preset is selected the RF input attenuation is placed in the automatic selection mode Special Rnction 1 0 Error 02 03 If the RF input attenuation is manually s...
Страница 321: ...l Settings Not Allowed with RF Level Measurements Manual setting of RF input attenuationis overridden when RF Level measurementsare selected TO OTHER MEASUREMENT CIRCUITS Block Diagram of RF Input Attenuation 3 232 RF Input Attenuation ...
Страница 322: ...binations of Errors 01 through 04 can be disabled or enabled by the operator to customize the behavior of the instrument to meet a particular set of measurementrequirements Specialfinction 8 8 Errors 01 through 04enabled sets up the Modulation Analyzer as a calibrated receiver Referto COMMENTS for further elaboration The followingtable lists the Error Messages conveyed by Errors 01 through 04 Erro...
Страница 323: ... disabled the accuracy of the displayed measurement and the fidelity of the signal at the output of the MODULATION OUTPUT AUDIO INPUT are not safeguarded When all the errors are enabled displayed results are calibrated and the output of MODULATION OUTPUT AUDIO INPUT is entirely safeguarded Disable Error 04 Inhibits Audio Autoranging When Error 04 is disabled the Modulation Analyzer automatically r...
Страница 324: ...peration It assures that the output from MODULATION OUTPUT AUDIO INPUT is safeguarded for most measurements Sometuned non modulationmeasurementmodes suchasfrequency do not completely safeguard the signal fidelity at this output since accurate demodulation is not the primary goal of that measurement mode Identify Currently Disabled Error Messages Use the Special Display and the Special Special Disp...
Страница 325: ...scribed in the table in this instruction Prefixes 40 to 99 Prefixes 40 to 99 are the Service Special Functions used to assist in troubleshooting an instrument fault discussedin detail in Section 8 The functions available include special internal measurements software control and special service tests and configurations Most instrument safeguards are relinquished If a ServiceSpecialF unctionis ente...
Страница 326: ...PCLkey alone once while the Special Display is active Ifthe SpecialDisplay is not active press the SPCL key twice to get this display The digit position corresponds to the special function prefix and the number displayed in that digit corresponds to the special function suffix HP IB PROGRAM CODES All special function codes are formed by the special function number followed by the code SP For examp...
Страница 327: ... Audio Range 1 I 40 AM 4 kHz FM 4 radians 4M 6 7 5 0 Audio Detector Response SUFFIXES PREFIXES Fast Response This display is interpreted as follows 7 2 RF FrequencyResolution 100 Hz 10 0 I 3 0 I RF and IF Filters I Automatic Selection RF High Pass Filter Out RF Power Range Automatic Selection I 6 1 I Automatic Level Control I Fast Response I 8 8 I Error Messaae Disable I All Errors Enabled Special...
Страница 328: ...Instrument Setting 7 2 8 8 RF Frequency Resolution 100 Hz Error Message Disable All Errors Enabled 10 1 RF Power Range Range 1 COMMENTS Omit Zero Suffixes If a special function has a suffix of zero the zero need not be entered For example 10 0 SPCL equals 1O SPCL However 22 2 SPCL does not equal 22 20 SPCL nor does 18 1SPCL equal 18 10 SPCL If entering a special function code evokes Error 21 inval...
Страница 329: ...lay 0 01 Hz resolution when the deviation being measured is less than 0 04 peak kHz and when the RMS detector is selected Because this special function is so complex it is not described in detail here Refer to Audio Range on page 3 183 for detailed tables for this function 3 RF and IF Filters Use this special function to change the Modulation Analyzer s RF and IF filters Refer to Filters RF and IF...
Страница 330: ...approximately 20 seconds 8 Error Message Disable Control Most combinations of Errors 01 through 04 can be disabled or enabled to customize the behaviour of the instrument to meet a particular set of measurement requirements When the Modulation Analyzer uses automatic selection of error messages these messages are selectively enabled depending on the measurement being made to assure the broadest ra...
Страница 331: ...he demodulatedpeak FM 13 AM Calibration for Another Instrumentin the HP 8902 and HP 8902 RF Signal Analyzer Family Use this special function to compute an AM calibration factor for another RF signal analyzer that has no internal calibrator or that has an internal calibrator that is to be cross checked For a complete procedure for AM calibration refer to AM Calibrationon page 3 141 13 0 Display the...
Страница 332: ...MHz can alsobe used to enable and displaythe calibration factor Fora completeprocedure for FM calibration refer to FM Calibration on page 3 155 17 0 Disable the FM calibration factor 17 1 Enable the FM calibration factor 17 2 Display the FM calibration factor Displays0 if not enabled 18 Tone Burst Receiver Use this special function to measure the frequency of squelch tones A time delay of NN ms is...
Страница 333: ...andwidth Enables setting of the value of the noise measurementbandwidth Displays the value of the noise measurementbandwidth 25 Current Value of External Attenuation Use this special function in conjunction with dB EXT ATTEN Blue Key LOG LIN to scale level measurements to correctly indicate the power at the input of an external attenuator or amplifier connected to the Modulation Analyzer For infor...
Страница 334: ...ion to display the LO frequency for the signal being measured 34 0 IF Frequency Measurement Use this special function to displaythe IF frequencyfor the signal being measured Special Function 3 enables you to manually select the IF for frequencies above 10 MHz Refer to Filters RF and IF on page 3 229 35 0 RF Level Measurement Enables the Modulation Analyzer to measure the peak RF power This measure...
Страница 335: ... measurementbecause of manual settings of special Wctions For example when frequency measurementsare made on a low levelinput signalwith high AM depth or when the RF input attenuation is improperly set This display is never output to the HP IB and typically indicates a transitory state in instrument operation Error messages are grouped by error code as follows Errors01 through 19 and 90 through 99...
Страница 336: ...ated value out of range Time Base oven cold Option 002 Power sensor not connected Power sensor cannot zero Calibrationfactor error Audio circuits underdriven Selective power measurement option series 030 RF Power will not calibrate HP IB only No input signal sensed by instrument lperating Errors Corrective Action Retuneto signal at input Increase RF input attenuation DecreaseRF input attenuation I...
Страница 337: ...5 Error 05often occurswhen FM or RM measurements are attempted on low levelsignals with high AM depth greater than 90 Error 05 disables MODULATION OUTPUT AUDIO INPUT Error 06 Maximum allowable input level is 7 Vrms 1W peak Error 07 If displayedduring modulation measurements increase audio range If displayed during level measure ments increase RF input attenuation or increase RF power range Error 0...
Страница 338: ... of the measurement ranges Special hnctions 1through 10 w a s user selected Select AUTOMATIC OPERATION and try the measurement again 0 IF level too low when making a reference measurement The reference is below 1 25V Increase the source level to between 1 25V and 2 5V 0 Either a ratio measurement was attempted with an inadequate reference measurement or the reference was not measured before the ra...
Страница 339: ...elated errors Error 24 Error 24 alwayscauses the issuance of a Require Service message on the HP IB Corrective Action Refer to service section of HP 8901B instrument manual Errors 40 through 89 Service errors are normally disabled Error Message Summary 3 251 ...
Страница 340: ... Performance Test 4 Audio F i l t e r s 4 18 Performance Test 5 Audio Measurements 4 20 PerformanceTest 6 Power Reference UsingReference Comparison 4 25 Performance Test 7 Power Reference UsingDC Substitution 4 26 Performance Test 8 Power Meter 4 29 Performance Test 9 SWR 4 31 Performance Test 11 High SelectivityGain Option Series 030 4 38 Table 4 1 Performance Test Record 4 40 Performance Test 10...
Страница 341: ...ed in Table 1 3 Recommended Test Equipment Any equipment that satisfiesthe critical specificationsprovidedin the table may be substituted for the recommended model s 4 3 PERFORMANCE TEST RECORD Results of the performance tests may be tabulated on the Performance Test Record at the end of the procedures The Performance Test Record lists all of the tested specifications and their acceptable limits T...
Страница 342: ...h 50 Hz to 10kHz rates 5to 99 depth 20 Hz to 10 kHz rates to 99 depth 50 Hz to 50 kHz rates 5to 99 depth 20 Hz to 100kHz rates 5 to 99 depth 90 Hz to 10kHz rates 20to 80 depth 50 AM depth 400 Hz and 1 kHz rates 50 Hz to 3 kHz bandwidth 50 AM depth 1 kHz rate 50 Hz to 3 kHz bandwidth l But not to exceed 50 kHz rateswith rms detector 2 Peak residuals must be accounted for in peak readings Refer to R...
Страница 343: ...36C HP 89016 1 MODULATION ANALYZER OUTPUT h Slap I y 1 g 000000 Egg 0000 0 0 Slap 10 INPUT AUDIO ANALYZER UODULAT I ON AUDIO INPUT 0 0 0 000000 0 0 0 0 0 0 AMI FY OUTPUT I I I I HP 11715A I AMIFM TEST SOURCE Figure 4 1 AM Performance Test Setup NOTE In the following procedure the RF modulation source can be connected either to a sensor module which i s connected to the Modulation Analyzer or direc...
Страница 344: ...and TRACK MODE T h e the AMFM test source s carrier frequencyto approximately 12 5 MHz Press TRACK MODE again to turn it off 6 On the Modulation Analyzer press AM Key in 2 0 SPCL to set the modulation range to automatic Set the other controls as follows HP Filter 50Hz LP Filter 3 kHz Detector AVG The display should show 0 01 or less Residual AM 0 01 AM Distortion 7 Set the audio analyzer s oscilla...
Страница 345: ...0 AM Measure the distortion The distortion should be 0 3 or less AM Distortion at 20 Hz Rate 50 AM 0 3 AM Flatness 14 Set the audio synthesizer to 1 kHz at 1 dBm Connect its output to the audio input of the AM FM test source See Figure 4 1 Fine adjust the audio synthesizer level for a Modulation Analyzer display of 80 AM NOTE Flatness of the audio synthesizer is critical for this test If the audio...
Страница 346: ...tual Upper 98 9 101 1 96 9 103 1 98 9 101 1 96 9 103 1 r Audio Synthesizer heauency Hzl I I I I I AM Limits REL ower I ctual I upper NOTE fl digit at a nominal reading of 80 0 is about fl of the reading in the RATIO mode 20 50 10 000 96 9 103 1 97 9 102 1 97 9 102 1 AM Rejection 20 On the Modulation Analyzer press RATIO to turn it off Set the HP FILTER to 50 H z and the 21 Set the audio synthesize...
Страница 347: ...er press QM Momentarily disconnectthe audio input to the AMFM test source and note the residual OM displayed on the Modulation Analyzer Residual OM 1 5 MHz IF rad 26 Reconnect the audio input of the AMFM test source Note the ModulationAnalyzer s displayed OM The displayed QM minus one half the residual OM noted in step 25 should be 0 030 rad peak or less AM Rejection with QM 1 5 MHz IF 0 030 rad P...
Страница 348: ...rates 400 kHz peak deviation 40 kHz peak deviation with 750 ps de emphasis 10to 1300 MHz carrier 20 Hz to 200 kHz rates 400 kHz deviation 40 kHz peak deviation with 750 ps de emphasis 400 kHz to 10 MHz carrier 20 Hz to 10 kHz rates lo kHz peak deviation 10to 1300MHz carrier 20 Hz to 100kHz rates 4 0 0 kHz peak deviation 40 kHz peak deviation with 750 ps de emphasis l But not to exceed 50 kHz rates...
Страница 349: ...ting measured FM is the residual FM of the Modulation Analyzer sinternal local oscillator FM accuracy is measured with the internal FM Calibrator which produces approximately34 kHz peak deviation at a 10 kHz rate A source which can produce wide band linear FM is modulatedat various FM rates and deviationsto measure distortion flatness and incidentalAM A specialAM FM test sourceis required for thes...
Страница 350: ...P Filter 3 kHz Detector AVG The display should read 4 Hz or less Residual FM at 560 MHz 50 Hz to 3 kHz bandwidth 4 Hz NOTE The equation for determining the residual FM limits i s residual FM in Hz 5 83 x carrier frequency in GHz 0 42 Hz For a carrier of 560 MHz the residuul FM limit is 3 7Hz Allowing for one digit of uncertainty gives a limit of approximately 4 Hz FM Accuracy at 10 kHz Rate 3 Conn...
Страница 351: ... On the Modulation Analyzer set RATIO on with LOG LIN set for a linear display Connect the FM 32 output of the AMFM test source to the Modulation Analyzer s INPUT without disturbing the AM FM test source s controls See Figure 4 2 Multiply the displayed ratio on the Modulation Analyzer by the calibration factor of step 4 For example if the display reads 12 52 REL and the calibration factor of step ...
Страница 352: ...tion Analyzer press AM Momentarily disconnect the audio input to the AM FM 50 kHz peak deviation test source and note the residual AM displayed on the Modulation Analyzer Residual AM 21 Reconnect the audio input of the AM FM test source Note the AM displayedon the Modulation Analyzer The displayed AM minus one half the residual AM noted in step 20 should be 0 2 or less FM Rejection at 1kHz Rate 50...
Страница 353: ...yzer s display should read between the limits indicated in the table FM Limits kHz Lower Actual Upper 9 79 10 21 9 79 10 21 30 Set the audio analyzer s oscillator to 10 kHz at 4V Connect its output to the audio input of the AMFM test source See Figure 4 2 Fine adjust the oscillator level for a Modulation Analyzer display of 10 kHz peak deviation 31 Set the audio analyzer to measure the distortion ...
Страница 354: ...must be accounted for in peak readings Refer to Residual Noise Effects in Detailed Operating lnstructions in Section3 2 For rms detector add f3 of reading Description A signal with a known amount of phase modulation is generated by frequency modulating a carrier at a known peak deviation asmeasured by the previously calibrated Modulation Analyz er and rate The relationship between the peak phase d...
Страница 355: ... connector Theprocedure is written for the latter case Procedure M Accuracy 1 Perform Performance Test 2 FM 2 On the AMFM test source set the test mode to FM Connect its FM output to the Modulation Analyzer s INPUT See Figure 4 3 3 Set the audio synthesizer to 200 Hz at 10 dBm Connect its output to the audio input of the AMFM test source See Figure 4 3 4 On the Modulation Analyzer press the blue k...
Страница 356: ... FM output of the AMFM test source to the Measuring Receiver s INPUT See Figure 4 3 Press AUTOMATIC OPERATION on the Modulation Analyzer Set the audio analyzer soscillator to 1kHz Connect its output to the audio input of the AM FM test source See Figure 4 3 NOTE For this test if the audio analyzer has floating input and output connectors the low connector should be grounded Connections should be m...
Страница 357: ... the high pass filter on the audio analyzer to 400 Hz The distortion should be 0 1 60 dB or less MDistortion at 1kHz Rate 400 rad Peak Deviation 1 5MHz IF 0 1 13 Reduce the audio analyzer s oscillator level to give a display of 40 rad peak deviation 14 On the Modulation Analyzer key in 3 1 SPCL The distortion measured on the audio analyzer should be 0 1 or less 9M Distortion at 1kHz Rate 40 rad Pe...
Страница 358: ...Hz rates l The 20 kHz low pass filter is intended wewave modulation Description A signal is frequency modulatedby a source which is known to have FM which is flat with rate The flatness of the demodulated signal is then measuredfor various modulation filters NOTE Flatness of the audio synthesizer i s critical for this test If the audio synthesizer has leveling capability switch it on Equipment AM ...
Страница 359: ... Actual Upper Measurement FM Detector AVG 6 Set the audio synthesizer level to give a display of approximately 25 kHz average deviation 7 Set the audio synthesizer frequency to the frequencies shown in the following table For each setting set RATIO on the Modulation Analyzer to off set all HP or LP FILTERS to off then set RATIO to on with LOG LIN set for a linear display and insert the filter indi...
Страница 360: ...00 or 1000 Hz f5 0 3 50 4 dB f l dB of reading 1 5 peak AM 150 Hz peak FM 0 6 rad peak OM 0 1 to 3 Vrms 50 Hz to 40 kHz 0 1 to 3 Vrms f4 Conditions 1 kHz rate lo AM 1 5 kHz FM or 1 5 rad OM lo0 mVrms external lo AM 1 5 kHz FM or 1 5 rad OM lo0 mMms external 1 kHz rate 3 kHz rate or 0 15 to 1 5 rad OM 3 kHz low pass filter 1 5 to 10 AM 0 15 to 1 5 kHz FM 20 Hz to 50 kHz bandwidth 40 C modulation mo...
Страница 361: ...Synthesizer HP 3336C Procedure Audio RMS Accuracy 1 On the Modulation Analyzer press the blue key then press INSTR PRESET the AUTOMATIC OPERATION key to preset the instrument Key in 30 0 SPCL to set the Modulation Analyzer to measure external audio rmslevel 2 Set the audio synthesizer to 50 Hz at 16 54 a m To produce 3V the synthesizer is set to deliver 1 5V or 16 54 dBm into 500 this becomes 3V w...
Страница 362: ... Modulation Analyzer The highest reading should not exceed 0 3 Maximum Residual Distortion 400 H z Input at 100 mV 0 3 11 Increase the audio synthesizer level to 16 5 dBm Slowly step the audio synthesizer down in frequency to 380 H z using 2 H z steps or h e r Note the highest distortion reading displayed on the Modulation Analyzer The highest reading should not exceed 0 3 Maximum Residual Distort...
Страница 363: ...p 1 12 1 12 1 12 1 12 18 On the Modulation Analyzer key in 30 0 SPCL to set the Modulation Analyzer to measure external audio rms level Note that the display reads approximately 1V Now set RATIO to on 19 Set the audio analyzer s oscillator level to OV or a level as low as possible without switching the instrument off but at most 10 mV 20 Increase the audio synthesizer slevel until the Modulation A...
Страница 364: ...izer sfrequency as shown in the following table without changingthe audio synthesizer samplitude For each setting the ModulationAnalyzer s display should read between the limits indicated in the table Distortion Limits X Lower Actual Upper 0 89 1 12 0 89 1 12 0 89 1 12 0 89 1 12 4 24 PerformanceTest 5 ...
Страница 365: ...1 9 Greater accuracy can be obtained by using a recently calibrated externalpower referenceor by following theprocedure in Performance Test 7 Power Reference Accuracy U s i n gDC Substitution Equipment Power Reference HP 435A Opt KO5 Sensor Module HP 11722A Procedure 1 Connect the input of the sensor module or a compatible power sensor connected to the 2 On the Modulation Analyzer press RF POWER P...
Страница 366: ...ementof the bridge dc voltages provides a way to determine the amount of RF power applied to the thermistor to a higher degree of accuracy than can be obtained by direct reading of the power meter NOTE Thepower level can be measured to an accuracy of 1 2 by thisprocedure A simpler but less accurate method for measuring the power reference can be found in the preceeding Performance Test 6 Power Ref...
Страница 367: ... 432A Power Meter on the most sensitive range then set the RANGE switch to 1m W 0 dE3m 6 Observe the voltage reading on the voltmeter If the reading is greater than 400 pV press and hold the FINE ZERO switch on the HP 432A Power Meter and adjust COARSE ZERO 80 that the voltmeter reads less than 200 pV then release the FINE ZERO switch Record the voltmeter reading for future reference V c o p VRFwi...
Страница 368: ...ation P 2VCOMF Vl vo vi v 4RH where H is the effectiveefficiencyof the thermistormountat 50 MHz as read from its label andR is the resistancemeasuredi n step 1 The computedpower shouldbe between0 988 and 1 012mW RF Power Reference Power 0 988 1 012 mW 4 28 PerformanceTest 7 ...
Страница 369: ... the range calibrator Equipment Range Calibrator HP 11683A Procedure Zero Set 1 Connect the power meter output of the range calibrator to the Modulation Analyzer s SENSOR 2 On the range calibrator set the function to standby polarity to normal and range to 1mW 3 On the Modulation Analyzer press the blue key then press INSTR PRESET the AUTOMATIC OPERATION key to preset the instrument Press RF POWER...
Страница 370: ...W 99 0mW 101 0rnW Function I Actual I Maximum I I Range to Range Error 5 On the range calibrator set the function to calibrate 6 On the Modulation Analyzer key in 10 0 SPCL to set the power meter ranging to automatic Press CALIBRATE then press the blue key then press SAVE CAL again the CALIBRATE key This normalizes the power reading to 1mW The CALIBRATE key light should be on 7 On the Modulation A...
Страница 371: ... On the Modulation Analyzer key in 10 3 SPCL Set the range calibrator srange to 100 p W The Modulation Analyzer s display should read between 0 099 and 0 101 m W 0 100mW f0 5 f l digit then rounded to the nearest 0 001 mW Accuracy within a Range 0 099 0 101 mW rev 13JUL87 Performance Test 8 4 30 1 ...
Страница 372: ...sor input is driven by a signal generator through an SWR bridge The reflected power is measured by a spectrum analyzer A reference line is first established by disconnectingthe output of the SWR bridge to create a high reflection open circuit RF INPUT 6 dB ATTENUATOR SWR BRIDQE Equipment Attenuator 6 dB HP 8491A Option 006 RF Spectrum Analyzer HP 8559AL182T Sensor Module HP 11722A S i g n a lGener...
Страница 373: ...ignal generator from 0 1 to 1300 MHz and note the level of the signal Adjust the spectrum analyzer s reference level as needed to set the average level of the signal to a convenient graticule reference Re sweep the signal generator and note the reference on the display NOTE If the signal generator or spectrum analyzer is incapable of complete coverage of the frequency range use whatever range is a...
Страница 374: ...he front panelinput connector As the frequencyof the input is changed the shape of the IF is determined NOTE Thisprocedure tests only instruments with the 12 5 kHz Adjacent Chunnel Filter Option 032 or 25 kHz Adjacent Channel Filter Option 033 or both Depending on the combination of these filters with the other available filter options Options 035 and 037 either filter can be defined as the wide o...
Страница 375: ... found 4 On the Modulation Analyzer key in 24 1 SPCL and 24 2 SPCL to establish and display the 5 T h e the signal generator down until the first minimum is found The display should read 2 dB current IF level as a level reference The display should read 0 dB or higher that is between 2 and 0 dB 12 5 kHz Filter Loss at First Minimum 2 dB 6 Tune the signal generator down until the display reads 6 00...
Страница 376: ...F level as a level reference The display should read 0 dB Tune the signal generator down until the first minimum is found The display should read 2 dB or higher that is between 2 and 0 dB 25 kHz Filter Loss at First Minimum 2 dB Tune the signal generator down until the display reads 6 00 dB Record the signal generator s frequency 25 kHz Filter Lower 6 dB Frequency kHz Tune the signal generator dow...
Страница 377: ...d 0 dB 12 5 kHz Filter Loss at First Minimum 2 dB 28 Tune the signal generator down until the display reads 6 00 dB Record the signal generator s frequency 12 5kHz Filter Lower 6 dB Frequency kHz 29 Tune the signal generator down 1 6 kHz The display should read 30 dB or less that is more negative 12 5 kHz Filter Loss at 1 6 kHz Below Lower 6 dB Comer 30 dB 30 Tune the signal generator down another...
Страница 378: ...he signal generator down until the display reads 6 00 dB Record the signal generator s frequency 25 kHz Filter Lower 6 dB Frequency kHz Tune the signal generator down 1 6 kHz The display should read 30 dB or less that is more negative 25 kHz Filter Loss at 1 6 kHz Below Lower 6 dB Comer 30 dB Tune the signal generator down another 3 kHz The display should read 80 dB or less 25 kHz Filter Loss at 4...
Страница 379: ...n035 2 On the Measuring Receiver key inthe following a 41 0SP Performs instrument PRESET b 150MHz Manually tunes the LO c 24 0SP Initializes Option 030 d 24 1SP Selects Option 035 filter displays IF reference level value e 30 kHz UP Increments LO up one channel spacing f 24 2SP Displays Option 035 filter ratio level value 3 Offsetthe signalgenerator U pone channel spacingby incrementingfi equency3...
Страница 380: ...RNAL LO signal generator to 800 455 MHZ at 0 dBm and connect itto the MeasuringReceiver sLO INPUTport onthe rear panel Allow allequipment 30 minute warmup minimum Filter Test of Option 030 CombinationWhich IncludesOption 037 10 On the MeasuringReceiver key inthe following a 41 0SP Perfonn instrument PRESET b 1200MHZ ManualtuneLOto eliminate internal LO interference c 23 1SP Select external LO d 24...
Страница 381: ...power level to 26 dBm Read t h e ratio displayed on the LEVELRATIO 2 m f1 m MeasuringReceiver 17 Change the signal generator power level to 10 dBm Read the ratio displayed on the MeasuringReceiver LEVELRATIO lOdB fl 5dB 4 38 2 Performance Test 10b rev 01OCT92 ...
Страница 382: ... level is setto produce a signal that isnear the upper measurement limitof the detector a level reference is set andtherange settingsheld The signallevel isthen decreasedby precisely 5dB andthe drop in displayed level is compared against the decrease inlevel IFgainstep accuracy ismeasured by increasing the attenuation of the attenuator in 5dB steps and comparingthe displayed reading with the incre...
Страница 383: ...d record the result Upper 1 059 1 059 1 059 1 059 1 059 1 059 1 059 IF RMS Detector Linearity I F Gain Accuracy 5 On the Modulation Analyzer key in 0 250 SPCL 0 2 S Shift 4 S 4 SPCL and 0 2 S 30 SPCL 6 Increase the signal generator level for a displayed reading of 1 000 7 Decrease the signal generator level by the exact amount indicated in the following table For each setting key in the Special hc...
Страница 384: ...t to produce a signal that is near the upper measurement limit of the detector a level reference is set and the range settings held The signal level is then decreased by precisely 5 dB and the drop in displayed level is compared against the decrease in level IF gain step accuracy is measured by increasingthe attenuation of the attenuator in 5 dB steps and comparing the displayed reading with the i...
Страница 385: ...ctly 5 dB Divide the displayed reading by 1 406 and record the result Limit Displayed Level Lower IF RMS Detector Linearity IF Gain Accuracy 5 On the Modulation Analyzer key in 0 390 SPCL 0 3 S Shift 4 S 4 SPCL and 0 3 S 30 SPCL 6 Increase the signal generator level for a displayed reading of 1 000 7 Decrease the signal generator level by the exact amount indicated in the followingtable For each s...
Страница 386: ...te 1 5 MHz IF 50 Hz Rate 1 5 MHz IF 20 Hz Rate 455 kHz IF 20 Hz Rate 455 kHz IF 50 Hz Rate 455 kHz IF 10 kHz Rate AM Rejection With FM 455 kHz IF With FM 1 5 MHz IF With 9M 1 5 MHz IF FM PERFORMANCE TEST Residual FM Residual FM at 560 MHz 50 Hz to 3 kHz bandwidth FM Accuracy at 10 kHz Rate FM Calibration Factor 40 kHz Modulation Range FM Calibration Factor 400 kHz Modulation Range FM Accuracy 4 kH...
Страница 387: ...n 1 kHz Rate 400 rad Peak Deviation 1 5 MHz IF 1 kHz Rate 40rad Peak Deviation 455 kHz IF AUDIO FILTERS PERFORMANCETEST Rate Hz Filter 200 50 Hz HP FILTER 2 000 50 Hz HP FILTER 1 000 300 Hz HP FILTER 10 000 300 Hz HP FILTER 1 000 3 kHz LP FILTER 100 3 kHz LP FILTER 10000 15 kHz LP FILTER 1 000 15 kHz LP FILTER 10000 20 kHz LP FILTER 1 000 20 kHz LP FILTER reu 17AUG87 Minimum 98 9kHz 94 9 kHz 98 9 ...
Страница 388: ...e 4th harmonic 1 kHz Rate 5th harmonic 400 Hz Rate 2nd harmonic 400 Hz Rate 3rd harmonic 400 Hz Rate 4th harmonic 400 Hz Rate 5th harmonic POWER REFERENCE PERFORMANCETEST USING REFERENCE COMPARISON RF Power ReferenceAccuracy POWER REFERENCE PERFORMANCETEST USING DC SUBSTITUTION RF Power Reference Power Minimum 2 88 Vrms 2 88 Vrms 2 88 Vrms 2 88 Vrms 96 mVrms 96 mVrms 96 mVrms 96 mVrms 3 01998 kHz ...
Страница 389: ...ption Combination032and 037 12 5 kHz Filter Loss at First Minimum 12 5 kHz Filter Loss at 1 6 kHz Below Lower 6 dB Comer 12 5 kHz Filter Loss at 4 6 kHz Below Lower 6 dB Corner 12 5 kHz Filter 6 dB Bandwidth 12 5 kHz Filter Loss at 12 kHz Above Lower 6 dB Corner 12 5 kHz Filter Loss at 15 kHz Above Lower 6 dB Comer Wide Filter Test Option Combination032and 033or 033and 037 25 kHz Filter Loss at Fi...
Страница 390: ...5 kHz Above Lower 6 dB Corner 25 kHz Filter Loss at 21 5 kHz Above Lower 6 dB Corner HIGH SELECTIVITY GAIN PERFORMANCE TEST OPTION SERIES 030 2374Ato 2636A IF Gain Accuracy Special Function0 2 S 4 S 3 Special Function0 2 S 4 S 1 Special Function0 2 S 4 7 Special Functions0 2 S 4 S 4 0 251 Special Function0 252 Special Function0 254 Special Functions0 250 0 2 S 31 HIGH SELECTIVITY GAIN PERFORMANCE ...
Страница 391: ...15 kHz and 20 kHz Low Pass Filter Gain 5 14 Adjustment 8 ALC Reference 5 15 Adjustment 9 FM Calibrator 5 16 Adjustment 10 FM Sensitivity 5 17 Adjustment 1 1 FM Flatness 5 18 Adjustment 12 FM Distortion and Incidental AM 1 5 MHz IF 5 19 Adjustment 13 cPM Sensitivity 5 21 Adjustment 14 AM Calibrator 5 23 Adjustment 15 AM Sensitivity 5 24 Adjustment 16 FM Distortion and Incidental AM 455 kHz IF 5 25 ...
Страница 392: ...ance can be performed without power applied theporixr should be removed Removal of the Modulation Analyzer s bottom cover is not necessary to perform these adjustments However if the bottom wver is removed hazardous voltage 1 2 0 Vac is nccessiblc A pin to pin coltage difference of 55 Vdc may bc found on man of thc Modulation Analyzer s circuit board conimtors Be careful while uorking on the circu...
Страница 393: ...nd Efficiency 5 5 POST REPAIR TESTS ADJUSTMENTS AND CHECKS Table 5 2 lists the performance tests adjustments and checks needed to calibrate or verify calibration of a repaired assembly The tests adjustments and checks are classified by assembly repaired The table is also useful as a cross reference between performance tests and assemblies when the failure is a specificationthat is slightlyout of l...
Страница 394: ...nt 12 FM Distortionand IncidentalAM 1 5 MHz IF Adiustment 15 AM Sensitivitv A10 Power Supply Regulators A11Counter Assembly A13 Controller Assembly A14 Remote InterfaceAssembly A15 RF Input Assembly A17 Input Mixer Assembly A18 IFAmplifier Assembly A19 LO Divider Assembly Assembly A20 LO ControlAssembly A21 Low FrequencyVCXO Filter A22 Low FrequencyVCXO Assembly A23 Sampler Assembly Assembly A24 H...
Страница 395: ... 2314A to 2636A 2642A and above 2642A and above A71 IF Amplifier Detector Assembly A72 IF Channel FilterAssembly Y1 Crystal Oscillator HP IB Functional Checks PerformanceTest 6 or 7 Power Reference Adjustment 18 or 19 Power Reference PerformanceTest 1 AM AM Accuracy at 10 kHz only Adjustment 14 AM Calibrator PerformanceTest 2 FM FM Accuracy at 10 kHz only Adjustment 9 FM Calibrator PerformanceTest...
Страница 396: ...upplies which are dependent upon it are checked Equipment Digital Voltmeter HP 3455A Procedure 1 Set the voltmeter to measure 15 Vdc Connect its input to AlOTP3 15V SW 2 Adjust A10R24 15V for 14 99 to f15 01 Vdc at AlOTP3 3 Check the other supplies with the voltmeter as indicated in the following table A1OTP4 15 2 14 8 5v A1OTP6 5 2 4 9 40V A1OTP7 42 5 A1OTP5 Adjustment 1 5 5 ...
Страница 397: ... 1 Allow the equipment to warm up for 15 minutes For Option 002 a warm up of the Modulation Analyzer of several days with covers on is recommended 2 Set the oscilloscope svertical sensitivity to view the Modulation Analyzer stime base output Set its horizontal scale for 10 ps per division Set the oscilloscope to trigger externally 3 Adjust AllC14 10 MHZ REF or for Option 002 Y1 COARSE and FINE for...
Страница 398: ... cable from the Modulation Analyzer s INPUT 2 Press RF POWER 3 Key in 0 024 SPCL to switch out the 5 25 MHz high pass filter and to set the RF Level Detector to normal output Then key in 49 31 SPCL to display the RF level with respect to RF ground These steps set the input for an RF level measurement and connect the internal voltmeter to the RF detector output 4 Adjust A15R42 DET OFS for a display...
Страница 399: ...f the 1MHz waveform is the same as the zero beat NOTE Improper adjustment of efficiencymay result in the loop easily breaking or not attaining phase lock Equipment Oscilloscope HP 1740A Signal Source HP 8640B or HP 3336C Figure 5 2 Sampler Efficiencyand OffsetAdjustment Test Setup Procedure 1 Set the signal source to 18 MHz CW at 0 a m 2 Connect the equipment as shown in Figure 5 2 The oscilloscop...
Страница 400: ...just A23R34 only when the input couplingis set to dc 8 A d j u s t A23R54 0for the same peak to peakamplitude onthe oscilloscopeas noted instep 5 I f the adjustment has not enough range a SetA23R54 fully ccw andrepeat steps 5to 7 b The signalamplitude step 5 Shouldbe greater thaninstep 8 with A23R54 adjustedfully ccw If it is not replace A23R55 by higher values of resistance as listed in the follo...
Страница 401: ...brate the sensor module using the RF power calibrator in the Modulation Analyzer Set LOG LIN to read in a m 4 Connect the sensor module s input directly to A19J3 LO OUT or for Option 003 the rear panel LO OUTPUT connector 5 On the Modulation Analyzer press FREQ Key in 650 MHz to set the LO to the bottom of its doubler band 6 Step the LO frequency up in 50 000 kHz steps Key in 50 000 d kHz for the ...
Страница 402: ...er range 9 Adjust A19R41 DBLRBAL for the minimum level of the 1 2 and 312 harmonics of the doubled signal over the swept range The 112 and 312 harmonics should be more than 30 dB below the doubled signal The doubled signal sweeps from approximately 600 to 1300 MHz with a level of approximately 2 dBm Use values within the range 121to 6190 changed the power must be rechecked over the entire doubler ...
Страница 403: ...not connect the audio oscillator to the Modulation Analyzer at this time The Modulation Analyzer s INPUT can be connected either directly to the CALIBRATION RF POWER OUTPUT or through a sensor module 2 On the Modulation Analyzer press the blue key then press INSTR PRESET the AUTOMATIC OPERATION key to preset the instrument Key in 45 16 SPCL to turn on the RF power calibrator This provides a signal...
Страница 404: ...he four digits of the display agree with the first four digits of the voltmeter reading to within f l digit 13 On the Modulation Analyzer key in 49 09 spcl 14 Adjust A5R23 AVG SENS for a display on the Modulation Analyzer between 141 3 and 141 5 or if the level has drifted slightly until the four digits of the display equals the voltmeter reading to within f l digit 15 On the Modulation Analyzer p...
Страница 405: ...nal generator to 11 MHz at 0 dBm with 30 AM at a 1 kHz rate Connect its F W output to the Modulation Analyzer s INPUT The signal source can be connected either to a sensor module or directly to the Modulation Analyzer s INPUT 2 On the Modulation Analyzer press the blue key then press INSTR PRESET the AUTOMATIC OPERATION key to preset the instrument Press AM Set DETECTOR to AVG 3 Set RATIO on with ...
Страница 406: ...module or directly to the Modulation Analyzer s INPUT 2 Press the blue key then press INSTR PRESET the AUTOMATIC OPERATION key to preset the instrument Key in 45 16 SPCL to turnon the R F power calibrator Thisprovides a signal for the Modulation Analyzer s input Key in 49 S Shift 1 SPCL to connect the internal voltmeter to a node which represents the average IF level which the ALC loop forces to e...
Страница 407: ...or is then set to modulate and the symmetry is adjusted as the demodulated signal is measured with the peak and peak detectors The computed peak deviation is checked and if out of limits a resistor is changed to bring the deviation within the proper limits NOTE This calibration adjustment is not critical Built in safeguards minimize the possibility of erroneow Calibration If conditions exist that ...
Страница 408: ...ment 9 FM Calibrator 2 Connect the CALIBRATIONAMFM OUTPUT to the INPUT The CALIBRATIONAMFM OUTPUT can be connected either to a sensor module or directly to the Modulation Analyzer s INPUT NOTE For best accuracy allow the Modulation Analyzer to warm up for at least one halfhour 3 Press FM then CALIBRATEL Allow at least two readings approximately 40 seconds to pass then adjust A4WO FM SENS for a dis...
Страница 409: ... synthesizer The AMFM test source can be connected either to a sensor module or directly to the Modulation Analyzer s INPUT 2 With the leveling on set the audio synthesizer to 1kHz at 5 dBm On the AM FM test source set the test mode to FM 3 On the Modulation Analyzer press the blue key then press INSTR PRESET the AUTOMATIC OPERATION key to preset the instrument 4 Tune the AMFM test source s carrie...
Страница 410: ...TEST SOURCE I 0 INPUT FYS4 OUTPUT I AUDIO AUDIO ANALYZER OUTPUT Figure 5 5 FM Distortion and Incidental AM 1 5 MHz Adjustment IF Test Setup Procedure 1 Connectthe equipmentas shownin Figure 5 5 TheAMFM test source output can be connected 2 Set the audio analyzer s oscillator to 100 kHz at 4V On the AMFM test source set the test 3 On the ModulationAnalyzer press the blue key then press INSTR PRESET...
Страница 411: ...FM 4 output of the AM FM test source to the Modulation Analyzer s INPUT 9 On the Modulation Analyzer set LP FILTER to 3 kHz Press AUTOMATIC OPERATION 10 Set the audio analyzer s oscillatorfrequencyto 1kHz and level for a display of 50 kHz deviation 11 On the Modulation Analyzer press AM Adjust A18R19 INC AM 1 5 MHZ IF for a minimum on the Modulation Analyzer display but less than 0 2 NOTE The spec...
Страница 412: ...TPUT Figure 5 6 M Sensitivity Adjustment Test Setup Procedure 1 Connect the equipmentas shown in Figure 5 6 TheAMFM test sourceoutput can be connected either to a sensor module or directly to the Modulation Analyzer s INPUT 2 Set the audio synthesizer to 1kHz at 4 a m On the AMFM test source set the test mode to FM 3 On the Modulation Analyzer press the blue key then press INSTR PRESET the AUTOMAT...
Страница 413: ...value as the display in kHz of step 5 f0 2rad NOTE If a test oscillator is used in place of the audio synthesizer the modulation rate must be measured with a counter or simply key in S Shift AUDIO FREQ The adjustment is then made to give a display e q d to the ratio frequencydeviation modulation rate 5 22 Adjustment 13 ...
Страница 414: ...o INPUT The CALIBRATION AMPM OUT PUT can be connected either to a sensor module or directly to the Modulation Analyzer s INPUT 2 Key in 13 0 SPCL This sets the instrument to display the AM computed from internal measurements 3 Adjust A50R45 A LVL for a display of 33 330 to 33 336 4 Key in 49 5 SPCL This Connects the internal voltmeter to measure the output le l from the AM calibrator The display s...
Страница 415: ...m Adjustment 14 AM Calibrator 2 Connect the CALIBRATION AMLFM OUTPUT to the INPUT The CALIBRATION AM FM OUTPUT can be connected either to a sensor module or directly to the Modulation Analyzer s INPUT NOTE For best accuracy allow the Modulation Analyzer to warm up for at least one halfhour 3 Press A M then CALIBRATE Allow at least two readings approximately 40 seconds to pass then adjust A2R6 AMSE...
Страница 416: ...ncidental AM is measured with FM set for a 1kHz rate and 5 kHz peak deviation The instrument is adjusted for minimum AM Equipment AMFM Test Source HP 11715A Audio Analyzer HP 8903B Signal Generator HP 8640B SIGNAL GENERATOR r HP 11715A AM FM TEST SOURCE I FW3Z OUTPUT r l o o o AUD IO INPUT Figure 5 7 FM Distortion and Incidental AM 455 kHz IF Adjustment Test Setup Procedure NOTE In the following p...
Страница 417: ...easure the distortion on the 10 kHz signal at the MODULATION OUTPUT AUDIO INPUT with 30 kHz of low pass filtering on the distortion analyzer 10 Adjust A17Lll FM DISTN 455 KHZ IF for minimum distortion but less than 0 1 lessthan 11 On the Modulation Analyzer set LP FILTER to 3 kHz 12 Set the audio analyzer s oscillator frequency to 1kHz and level for 5 kHz peak deviation on the 13 On the Modulation...
Страница 418: ...OWER OUTPUT to the INPUT The CALIBRATIONRF POWER OUTPUT can be connected either to a sensor module or directly to the Modulation Analyzer s INPUT 2 Press the blue key then press INSTR PRESET the AUTOMATIC OPERATION key to preset the instrument Key in 45 16 SPCL to turnon the F W power calibrator This provides a signal for the Modulation Analyzer s input 3 Key i n 34 0SPCLto set the instrument to m...
Страница 419: ...P 435A Opt KO5 Sensor Module HP 11722A Procedure 1 Connect the sensor module s cables to the SENSOR and INPUT of the Modulation Analyzer Connect the sensor module s input to the CALIBRATION RF POWER OUTPUT If a sensor module is not available connect the Modulation Analyzer s INPUT directly to the CALIBRATIONRF POWER OUTPUT 2 On the Modulation Analyzer press the blue key then press INSTR PRESET the...
Страница 420: ...Analyzer press ZERO and wait for the power sensor to zero 7 On the Modulation Analyzer press RF POWER Press RATIO and check that LOG LIN is in the linear mode The display should read between 99 9 and 100 1 REL 8 Connect the sensor module to the CALIBRATION RF POWER OUTPUT of the Modulation Analyzer Press ZERO and allow the instrument to zero Adjust A32R4 LEVELADJ for a reading between 99 9 and 100...
Страница 421: ...obtained by direct reading of the power meter NOTE After adjustment the accuracy of the Modulation Analyzer s power refer ence will be 0 7 A simpler but less accurate method for adjusting the power reference can be found in Adjustment 18 Power Reference Using Reference Comparison Equipment Digital Voltmeter HP 3455A Power Meter HP 432A Thermistor Mount HP 478A Opt H75 Procedure 1 On the Modulation...
Страница 422: ...ATION ANALYZER POS VCOMP 0 0 000000 0000 0 0 0 0 0000 0 HP 432A POWER METER 0000 DIGITAL VOLTMETER 0 0 0 nnoooo 00000 0 NEO VRF I CALIBRATION RF P W E R OUTPUT HP 478A THERMISTOR MOUNT Figure 5 8 Power ReferenceAdjustment Test Setup 7 On the Modulation Analyzer key in 45 0 SPCL to switch the power reference o f f 8 Set the HP 432A Power Meter RANGE to COARSE ZERO and adjust the front panelCOARSE Z...
Страница 423: ... of V for 1mW from the equation where H is the effective efficiency of the thermistor mount at 50 MHz as read from the mount s label Desired VI Vdc 15 Adjust A32R4 LEVELADJ until the voltmeter reading is the same as V computed in step 14 If the adjustment runsout of range replace A32Fl 5 with 7100fl and readjust A32R4 5 32 Adjustment 19 ...
Страница 424: ... function to standby 8 On the ModulationAnalyzer press RF POWER Press ZERO and wait for the instrument to zero 9 On the range calibrator set the function to calibrate input on the Modulation Analyzer s display approximately1mW MLTVIB The Modulation Analyzer s display should read between 204 and 236 Hz 10 On the Modulation Analyzer press CALIBFMIX then press the blue key then press SAVE CAL again t...
Страница 425: ... the Modulation Analyzer off and extend the A53 RF Power Assembly Connect the extender cable to the RF Power Assembly Connect the range calibrator to the sensor connector on the extender cable Switch the Modulation Analyzer off and extend the A53 RF Power Assembly Reconnect the two cables on the top of the assembly Switch the Modulation Analyzer back on Repeat steps 7 to 14 Adjust A53R16 RNG 5 for...
Страница 426: ... 2 On the Modulation Analyzer press the blue key then press INSTR PRESET the AUTOMATIC OPERATION key to preset the instrument Key in 30 0 SPCL to set the instrument to measure and display the voltage at the MODULATION OUTPUT AUDIO INPUT connector with the audiotrue rms detector Key in 49 7 SPCL to measure and displaythe output of the audiotrue rms detector The displayed voltage will be ten times t...
Страница 427: ...IO DISTN Adjust A52R44 NOTCH FLTR GAIN for a display on the Modulation Analyzer between 99 9 and 100 1 10 Set the audio oscillator frequency to 800 Hz 11 On the Modulation Analyzer press the blue key then press 400 Hz DISTN the PEAK key The Modulation Analyzer s display should read greater than 98 5 36 Adjustment 21 ...
Страница 428: ... Digital Voltmeter HP 3455A Procedure 1 Connect the voltmeter to A13TPlO 5V Measure and record the dc voltage with respect to ground Voltage at Al3TPlO Vdc 2 Connect the voltmeter to A13TP12 12V Measure and record the dc voltage with respect to ground Voltage at A13TP12 Vdc 3 Make the following calculations 2 5 x Voltage at Al3TPlO x Voltage at A13TP12 Vdc Vdc 4 Make the following calculation 0 95...
Страница 429: ...stede475 P O Box 999 The Netherlands Tel 20 437771 Telex 18919 hpner nl NL 1183 AG AMSTELVEEN SOUTH EAST EUROPE Hewlett Packard S A World Trade Center 110 Avenue Louis Casai 1215 Cointrin GENEVA Switzerland Tel 022 98 96 51 Telex 27225 hpser OTHER INTERNATIONAL AREAS Hewlett Packard Co IntercontinentalHeadquarters 3495 Deer Creek Road PAL0 ALTO CA 94304 Tel 415 857 1501 Telex 034 8300 Cable HEWPAC...
Страница 430: ... INPUT 3 187 3 199 3 201 audio filters 3 179 audio level measurements 3 201 audio range selection 3 241 audio range 3 183 automatic cal factors 3 71 automatic level control 3 242 automatic tuning 3 115 AUTO TUNING 3 115 AUTOMATIC OPERATION 3 207 n CALIBRATE In AM measurements 3 141 In FM measurements 3 155 RF power calibration 3 71 calibration factors AM 3 244 calibration Eactors FM 3 244 calibrat...
Страница 431: ... HP IB 8901AI01B codedifferences 3 45 8901 automaticallyselectspre display 3 174 abort 3 32 address 3 33 alpha characters 3 13 ASCII charactersnot used 3 14 capabilities 3 19 3 20 3 21 CLEAR key 3 21 3 22 clear 3 24 3 209 code sequence 3 16 codes 3 37 3 38 C O I I I I I L 3 13 data Output 3 18 device clear 3 24 exampleprogram for RF power cal factor entry 3 81 example 3 17 invalidcharacters 3 14 m...
Страница 432: ...qualization 3 159 program example for entering RF power cal factors 3 81 pulsed phase modulation 3 172 PREVIOUS RATIO 3 215 3 243 pull Out cards 3 2 R RANGE HOLD 3 213 range audio 3 183 range modulation 3 183 ratio measurements common 3 218 recalibrating RF power reasons 3 78 RECAL receiver setting up the 8901 as 3 235 recorder output for RF power measurements 3 87 remote control RF switch 3 107 r...
Страница 433: ...3 85 3 246 37 3 72 3 74 3 246 special special display 3 240 spurious signals check for using the IF output 3 103 squelch tone measurement 3 165 squelching automatic if the input signal drops 3 154 SRQ 3 26 status bit 3 32 stepping frequency 3 116 3 117 switch remote control RF 3 107 STORE 3 223 T table of calibration factors 3 71 table of calibration factors storing 3 79 time base 3 3 tone burst r...
