Wiltron 681 A Series Operation Manual Download

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490 JARVIS DRIVE
MORGAN HILL, CA 95037-2809

SERIES

681XXA

SYNTHESIZED SWEEP GENERATOR

OPERATION MANUAL

P/N: 10370-10250

REVISION: A

PRINTED: JANUARY 1993

Summary of Contents for 681 A Series

Page 2: ...ges for equipment returned to WIL TRON for warranty repairs Obligation is limited to the original purchaser WILTRON is not liable for consequential damages LIMITATION OF WARRANTY The foregoing warranty does not apply to WILTRON connectors that have failed due to normal wear Also the warranty does not apply to defects resulting from improper or inadequate mainte nance by the Buyer unauthorized modi...

Page 3: ... display format and instructions for performing sweep generator operations Chapter contents are detailed immediately following the tab Chapter 4 Local Operation Menu Maps Chapter 4 provides menu maps that support the local front panel operating instructions found in Chapter 3 It includes menu maps for all of the frequency power level and modulation modes of op eration plus system configuration Cha...

Page 4: ...descriptions for the AUX I O and IEEE 488 GPIB connectors Appendix B Performance Specifications Appendix B lists the performance specifications for the Series 681XXA Synthesized Sweep Generator Supplements This tab provides a repository for application notes and other material used to supplement manual chapters Index Provides a subject index Table of Contents Continued ii 681XXA OM ...

Page 5: ...PE OF MANUAL 1 3 1 2 INTRODUCTION 1 3 1 3 DESCRIPTION 1 3 1 4 IDENTIFICATION NUMBER 1 4 1 5 RELATED MANUALS 1 4 1 6 OPTIONS 1 4 1 7 PERFORMANCE SPECIFICATIONS 1 5 1 8 RECOMMENDED TEST EQUIPMENT 1 6 Chapter 1 General Information ...

Page 6: ...Figure 1 1 Series 681XXA Synthesized Sweep Generator ...

Page 7: ...ocessor based synthesized signal sources with high resolution phase lock capa bility They generate both broad full range and narrow band sweeps and discrete CW frequencies across the frequency range of 10 MHz to 40 GHz All functions of the sweep generator are fully controllable lo cally from the front panel or remotely except for power on standby via the IEEE 488 General Purpose Interface Bus GPIB...

Page 8: ...y the sweep generator The WILTRON part number for the PM is 10370 10254 The MM supplies service information for all models in the 681XXA se ries The service information includes functional circuit descriptions block diagrams performance verification tests calibration procedures troubleshooting data maintenance procedures and assembly level drawings The WILTRON part number for the MM is 10370 10252...

Page 9: ...instrument providing 50 mW RF output power in the 2 20 GHz frequency range This option is only available for mod els 68137A and 68147A Option 16 High Stability Time Base Adds an ovenized 10 MHz crystal oscillator with 5 x 10 10 day frequency stability Option 17 No Front Panel Deletes the front panel for use in remote control applications where a front panel display or key board control are not nee...

Page 10: ... 40 GHz Input Z 50Ω Resolution 1 Hz Other External Time Base Input EIP Microwave Inc Model 578A with External Mixer Option 91 26 5 to 40 GHz Power Meter with Power Sensor Range 30 to 20 dBm 1µW to 100 mW Hewlett Packard Model 437B with Power Sensor HP 8487A 0 01 to 50 GHz Oscilloscope Bandwidth DC to 150 MHz Vertical Sensitivity 2 mV division Horiz Sensitivity 50 ns division Tektronix Inc Model 24...

Page 11: ... 2 5 Warmup Time 2 6 Operating Environment 2 6 2 4 GPIB SETUP AND INTERCONNECTION 2 7 Interface Connector 2 7 Cable Length Restrictions 2 7 GPIB Interconnection 2 8 Setting the GPIB Address 2 8 Selecting the Line Terminator 2 9 Selecting a GPIB Emulation 2 10 2 5 PREPARATION FOR STORAGE SHIPMENT 2 11 Preparation for Storage 2 11 Preparation for Shipment 2 11 Chapter 2 Installation ...

Page 12: ...ontainer or cushioning material is damaged retain until the contents of the ship ment have been checked against the packing list and the sweep gener ator has been checked for mechanical and electrical operation If the shipment is incomplete or if the sweep generator is damaged me chanically or electrically notify your local sales representative or WIL TRON Customer Service If either the shipping c...

Page 13: ...15 Vac or 230 Vac operation Figure 2 1 If the selector drum setting is incorrect for the line voltage available change it to the correct setting as follows Step 1 Remove the power cord from the line voltage module Step 2 Insert the blade of a small screwdriver into the slot at the top center of the module and pry open the cover Step 3 Remove the voltage selector drum by pulling it straight out Ste...

Page 14: ...ure 2 2 Then plug the male end of the power cord into a three wire power line outlet Standby Op eration Whenever the sweep generator is not being used it should be left connected to the power source and placed in standby This keeps the internal timebase frequency reference at operating temperature On the front panel press LINE to switch the 681XXA from OPERATE green LED on to STANDBY orange LED on...

Page 15: ...to assure stable opera tion Operating Environment The 681XXA can be operated within the following en vironmental limits Temperature 0 C to 55 C 32 F to 131 F Humidity 5 to 95 relative at 40 C Altitude up to 4600 meters approximately 15 000 feet Cooling Internal cooling is provided by forced airflow from the fan mounted on the rear panel CAUTION Before installing the 681XXA in its operat ing enviro...

Page 16: ...ccommodate up to 15 instruments at any one time To achieve design performance on the bus proper timing and voltage level relationships must be maintained If either the cable length be tween separate instruments or the cumulative cable length between all instruments is too long the data and control lines cannot be driven properly and the system may fail to perform Cable length restrictions are as f...

Page 17: ...ength Setting the GPIB Address The default GPIB address is 5 If a different GPIB address is desired it can be set from the front panel using the Configure GPIB Menu To change the GPIB address first press the front panel main menu key labeled SYSTEM The Sys tem Menu shown below is displayed Now press the menu soft key Config The System Configuration Menu shown below is displayed To go to the Config...

Page 18: ...R ASCII character or both the carriage re turn and line feed CR LF ASCII characters Which character is used depends upon the requirements of the system controller Most modern controllers can use either CR or CR LF while many older control lers require one or the other Consult the controller s manual for its particular requirements From the Configure GPIB Menu display you can se lect which GPIB ter...

Page 19: ...dard Commands for Programmable Instruments SCPI version 1991 0 In addition the sweep generator is able to emulate several signal sources It responds to the published GPIB commands of the following signal sources WILTRON Model 6600 WILTRON Model 6700 GPIB SETUP AND INSTALLATION INTERCONNECTION 2 10 681XXA OM ...

Page 20: ...hese two options is possible instructions for packaging and shipment are given below Use a Suitable Container Obtain a corrugated cardboard carton with a 275 pound test strength This carton should have inside di mensions of no less than six inches larger than the unit dimensions to allow for cushioning Protect the Instrument Surround the unit with polyethylene sheeting to pro tect the finish Cushi...

Page 21: ...dex Telephone 01 64 46 65 46 FAX 01 64 46 10 65 INDIA ACCUTROL SYSTEMS PRIVATE LIMITED Nirmal 15th Floor Narimen Point Bombay 400 021 Telephone 011 91 22 202 2220 011 91 22 204 7187 FAX 011 91 22 202 9403 ISRAEL TECH CENT LTD 7A Pinhas Rosen Street Tel Aviv 69356 Telephone 03 481958 FAX 03 481958 ITALY WILTRON Sp A Roma Office Via E Vittorini 129 00144 Roma EUR Telephone 06 5005171 FAX 06 5005273 ...

Page 22: ... 8 3 4 DATA ENTRY AREA 3 10 3 5 INSTRUMENT START UP 3 12 Powering Up the 681XXA 3 12 Start Up Display 3 12 Standby Operation 3 12 Self Testing the 681XXA 3 13 Resetting to Default Parameters 3 13 3 6 ENTERING DATA 3 15 Opening the Parameter 3 15 Editing the Current Value 3 16 Entering a New Value 3 17 3 7 CW FREQUENCY OPERATION 3 18 Selecting CW Mode 3 18 Selecting a CW Frequency 3 18 Chapter 3 Lo...

Page 23: ...r Level 3 36 Level Offset 3 39 3 10 POWER LEVEL SWEEP OPERATION 3 40 Selecting CW Power Sweep Mode 3 40 Setting CW Step Size and Dwell Time 3 41 Selecting a CW Power Sweep Trigger 3 42 Selecting a Power Level Sweep Range 3 43 Selecting a Sweep Frequency Step Power Mode 3 45 Setting Power Level Step Size 3 46 3 11 SIGNAL MODULATION 3 47 Amplitude Modulation Operating Modes 3 47 Providing Amplitude ...

Page 24: ...ower Slope 3 61 3 15 SYSTEM CONFIGURATION 3 63 Configuring the Front Panel 3 64 Configuring the Rear Panel 3 65 Configuring the RF 3 66 Configuring the GPIB 3 67 Setting Increment Sizes 3 68 3 16 MASTER SLAVE OPERATION 3 69 Connecting the 681XXAs 3 69 Analog Sweep Mode 3 70 Step Sweep Mode 3 71 ...

Page 25: ...panel data display area and data entry area that identify and describe all front panel controls in puts and outputs An annotated diagram of the menu display format showing where the current frequency power and modulation information is dis played Instructions for performing sweep generator operations namely fre quency and frequency sweep power level and power sweep signal modulation saving and rec...

Page 26: ...r rent status of the 681XXA in a menu display for mat This information includes the operating mode of the instrument the value of the active frequency and power level parameters and the modulation status Menu Keys Menu keys provide for selecting the operating mode parameters and configuration of the sweep gener ator LINE RF OUTPUT 50 CAUTION RF OUTPUT MAY EXCEED 100mW OPERATE STANDBY SYNTHESIZED S...

Page 27: ...ors The front panel has both input and output connec tors Modulation Connectors The modulation connectors provide for applying ex ternal AM FM or Square Wave modulation to the RF output signal External ALC Connector The external ALC connector provides for leveling the RF output signal externally using either a detector or a power meter RF Output Connector The RF output connector provides RF output...

Page 28: ...f the menu display and identifies the dis play elements It also shows the placement of the menu keys in rela tion to the display The paragraphs that follow provide descriptions of the menu display elements and the menu keys LOCAL FRONT DATA DISPLAY PANEL OPERATION AREA SYSTEM MODULATION CW SWEEP SELECT FREQUENCY CONTROL LEVEL ALC SELECT LEVEL CONTROL Main Menu Keys Frequency Mode Title Bar Frequen...

Page 29: ...e Bars Each type of signal modulation AM FM Square Wave has a separate title bar on the display Parameter Areas The parameter areas show the frequency power level and modulation information for the current 681XXA setup Frequency Parameters Area The current CW frequency in GHz or the start and stop fre quencies of the current frequency sweep range in GHz are displayed in this area Power Level Param...

Page 30: ...onal description of each main menu follows CW SWEEP SELECT This menu lets you select between CW Analog Step and Manual Sweep frequency modes FREQUENCY CONTROL In CW frequency mode this menu lets you select the CW fre quency parameter F0 F9 or M0 M9 to use In the Analog Step or Manual Sweep frequency mode this menu lets you select the sweep range parameters Full F1 F2 F3 F4 F5 dF or F6 dF to use In...

Page 31: ... The cursor is displayed on all sub menus of the current menu until a differ ent main menu key is pressed When the SYSTEM key is pressed the System menu is displayed The System menu and its sub menus do not contain a main menu key cursor Menu Soft Keys As shown on the left five menu soft keys are lo cated below the data display and five menu soft keys are located to the right of the data display I...

Page 32: ...used to increase or de crease the value of the parameter The unit size of the increase or decrease that occurs each time the or pad is pressed is determined by the cursor posi tion In addition when editing frequency power level and time parameters the incremental size can be set to a specific value using a system configuration sub menu Once set and activated each time the or pad is pressed the par...

Page 33: ...he param eter s value increases or decreases by the set amount KEYPAD The numeric keypad provides for entering fre quency power level time and number of steps pa rameters and GPIB address values The key functions as a change sign key during any keypad entry CLEAR ENTRY Key When a parameter is open for editing the CLEAR ENTRY key is used to clear the parameter entry BACK SPACE Key The BACK SPACE ke...

Page 34: ...layed until the sweep generator has loaded all programs Upon completion of power up the 681XXA returns to the exact configuration it was in when last turned off Standby Operation Whenever the sweep generator is not being used it should be left connected to the power source and placed in standby Standby operation provides power to keep the internal time base at operating temperature This assures sp...

Page 35: ...ion To perform a self test from any menu press SYSTEM Then when the System Menu shown below is displayed press Selftest Resetting to Default Pa rameters You can reset the 681XXA to the factory selected de fault parameter values at any time during normal operation The default parameters are shown in Ta ble 3 1 on the following page NOTE Resetting the instrument clears the setup presently in place I...

Page 36: ... 0 11 0 14 0 17 0 20 0 3 5 2 0 40 0 2 0 5 0 8 0 11 0 14 0 17 0 20 0 1 0 681XXA MODEL NUMBER POWER LEVEL PARAMETERS dBm L0 L1 L2 L3 L4 L5 L6 L7 L8 L9 68137A 1 0 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 68147A 1 0 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 68163A 1 0 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 68169A 1 0 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 681XXA MODEL NUMBER SWEEP TIME STEP SWEEP LEVEL SWEEP LEVEL OFF...

Page 37: ...l parameters If you wish to follow along on your synthesizer you can obtain this same menu display by resetting your instrument press SYSTEM then press Reset Opening the Parameter In order for the value of a parameter to be changed the parameter must first be opened To open the frequency parameter from the above menu press Edit F1 The menu display now changes to show that the menu soft key Edit F1...

Page 38: ...turn the knob clock wise or counter clockwise to increase or decrease the value of the parameter by the unit size Turning the knob rapidly changes the value of the parame ter in larger steps Using a Set Increment When editing frequency power level and time pa rameters you can increase or decrease the parame ter s value by a set amount each time the or pad is pressed or the rotary data knob is turn...

Page 39: ... terminated in GHz MHz kHz or Hz however it is al ways displayed on the data display in GHz A time entry may be terminated in Sec ms µs or ns however it is always displayed on the data display in Sec If you make an error during data entry either 1 press BACK SPACE to delete the entry one charac ter at a time starting from the last character en tered or 2 delete the entire entry by pressing CLEAR E...

Page 40: ...eset it automatically comes up operating in the CW frequency mode Selecting a CW Frequency There are several ways to select a CW frequency for output You can 1 edit the current frequency 2 en ter a new frequency or 3 select one of the 20 pre set frequency parameters Editing the Current Frequency Press Edit F1 to open the frequency parameter then edit the current CW frequency using the cur sor cont...

Page 41: ...ts you tag edit or output a frequency from the list Use the cursor control key to select a frequency from the frequency list The selected frequency is highlighted in reverse video and displayed in full be low the frequency list Press Tag to mark a selected frequency place an F in front of it If the frequency is already tagged pressing Tag will untag it remove the F Tagging selected frequencies let...

Page 42: ...nd Scan Dn keys Return to the CW Frequency Control menu by press ing Previous Menu Selecting a Power Level While in the CW frequency mode you can edit the current CW frequency output power level or enter a new output power level Editing the Current Power Level Press Edit L1 to open the power level parameter then edit the current power level using the cursor control key or rotary data knob To close...

Page 43: ... lets you set the ramp speed and turn the CW ramp on off To set ramp speed press Sweep Time The sweep time parameter opens for editing Edit the current sweep time using the cursor control key or rotary data knob or enter a new sweep time using the key pad and appropriate termination key The sweep time entered must be in the range of 30 ms to 99 sec To close the open sweep time parameter when you a...

Page 44: ...tor s output frequency is swept between selected start and stop frequencies When the sweep width is 50 MHz the sweep is phase lock corrected at both the start and stop frequencies and at each band switch point When the sweep width is 50 MHz only the center frequency of the sweep is phase lock corrected To place the 681XXA in analog sweep frequency mode press the main menu key CW SWEEP SELECT At th...

Page 45: ...arameter for editing press Sweep Time Edit the current sweep time using the cursor control key or the rotary data knob or en ter a new sweep time using the key pad and appro priate termination key To close the open sweep time parameter once you have set the desired time press Sweep Time or make another menu selection To go to the Analog Sweep Trigger menu from this menu press Trigger Menu Sweep tr...

Page 46: ...ingle sweep starts when the trigger key is pressed If a sweep is in progress when the key is pressed it aborts and resets To go to the Analog Sweep Trigger menu shown be low from the Analog Sweep Ramp menu press Trigger Menu To select a sweep trigger mode press its menu soft key A message showing the sweep trigger mode se lected appears on the right side of frequency title bar When you are finishe...

Page 47: ...681XXA in step sweep frequency mode press the main menu key CW SWEEP SELECT At the resulting menu display press Step The Step Sweep Menu shown below is then displayed This menu lets you perform the following Select a sweep range edit the sweep start and stop frequency parameters Go to the sweep ramp menu set the dwell time per step the step size or number of steps and select a sweep trigger Select...

Page 48: ...ress Step Size to open the step size parameter Press Num of Steps to open the number of steps pa rameter Open the parameter you wish to change then edit the current value using the cursor control key or the rotary data knob or enter a new value using the key pad and appropriate termination key When you have finished setting the open parameter close it by pressing its menu soft key or make another ...

Page 49: ...eps between the start and stop frequencies are controllable from the manual sweep menu To place the 681XXA in manual sweep frequency mode press the main menu key CW SWEEP SELECT At the resulting menu display press Manual The Manual Sweep menu shown below is then dis played This menu lets you perform the following Select a sweep range edit the start and stop frequency parameters Set the step size o...

Page 50: ... opens the stop frequency parame ter Edit the open frequency parameter using the cursor control key or the rotary data knob When you are finished close the open parameter by pressing its menu edit soft key or by making another menu se lection Entering New Start Stop Frequencies To enter a new sweep range start by opening either the start or stop frequency parameter press Edit F1 or Edit F2 Enter a...

Page 51: ...rmined by the dF fre quency parameter F6 dF provides a symmetrical frequency sweep about the center frequency F6 The sweep width is determined by the dF fre quency parameter To select one of the preset sweep ranges from any sweep frequency mode menu press the main menu key FREQUENCY CONTROL The Sweep Frequency Control menu shown below is displayed This menu lets you perform the following Select a ...

Page 52: ...l or enter a new output power level for the frequency sweep Editing the Current Power Level Press Edit L1 to open the power level parameter then edit the current power level using the cursor control key or rotary data knob To close the open power level parameter press Edit L1 or make an other menu selection Entering a New Power Level Press Edit L1 to open the power level parameter then enter the n...

Page 53: ...produces an intensified dot on a CRT display at each marker fre quency Intensity markers are only available in the analog sweep frequency mode and are obtained from a momentary dwell during the sweep at each marker frequency To output markers during a sweep you must first se lect tag the marker frequencies from the Marker List menu then turn on the marker output To go to the Marker List menu from ...

Page 54: ...ready tagged pressing Tag will untag it re move the m Activating Markers The soft keys Video Markers and Intensity Markers toggle the markers on and off Video Markers To output the tagged marker fre quencies as video markers during an analog or step sweep press Video Markers Video markers will be displayed on the CRT for all tagged marker frequen cies that are within the sweep frequency range Inte...

Page 55: ...mode for analog sweeps start with the Analog Sweep Menu display to select the alternate sweep mode for step sweeps start with the Step Sweep Menu display shown be low To go to the Alternate Sweep menu shown below from the Step Sweep menu press Alt Swp Menu This menu lets you perform the following Turn the alternate sweep mode on off Go to the alternate range menu to select a sweep range for the al...

Page 56: ... the alternate sweep is now active Now press Previous Menu to return to the Step Sweep Menu display or the Analog Sweep Menu display if operating in analog sweep frequency mode Notice the changes to the Step Sweep Menu display shown below These changes indicate that the al ternate sweep frequency mode is active Now press Alt Swp Menu to return to the Alternate Sweep menu LOCAL FRONT SWEEP FREQUENC...

Page 57: ... Sweep menu press Alt Level Select the power level for the alternate sweep range L0 L1 L2 L3 or L4 The menu then displays the current level parameter for the selected power level If you wish to change the level use the menu edit soft key to open the parameter then edit it A menu edit soft key is also provided to let you change the power level of the main sweep When you are done selecting the power...

Page 58: ...is menu lets you perform the following Edit the power level parameter Edit the level offset parameter Turn level offset on off Selecting a Power Level There are several ways to select a power level for output You can 1 edit the current power level 2 enter a new power level or 3 select one of the 10 preset power level parameters Editing the Current Power Level Press Edit L1 to open the power level ...

Page 59: ...vel List This menu lets you select a power level from the list to tag edit or output Use the cursor control key to select a power level from the level list The selected power level is high lighted in reverse video and displayed in full below the level list Press Tag to mark a selected power level place an L in front of it If a power level is already tagged pressing Tag will untag it remove the L T...

Page 60: ...quare or if tagged an L highlighted in reverse video When you are finished press Previous Menu to re turn to the Level Control menu display Scanning Tagged Levels To go to the Tagged Lev els menu shown below from the Level Control menu press Tag Lvl Menu This menu lets you select the tagged power levels for output using the Scan Up and Scan Dn keys Return to the Level Control menu display by press...

Page 61: ...value and apply it to the dis played power level go to the Level Menu Then press Edit Offset As shown in the following menu this opens the offset parameter for editing Edit the current offset value using the cursor con trol key or rotary data knob or enter a new offset value using the keypad and appropriate terminator key To close the open offset parameter when you are done press Edit Offset or ma...

Page 62: ...a single CW fre quency Menus provided let you set or select the sweep range the step size the dwell time per step and the sweep trigger To place the 681XXA in a CW power sweep mode from a CW frequency menu press the main menu key LEVEL ALC SELECT At the resulting menu display press Lvl Swp The CW Level Sweep Menu shown below is displayed This menu lets you perform the following Select a power leve...

Page 63: ...mber of steps and go to the trigger menu Press Dwell Time to open the dwell time per step parameter Press Step Size to open the step size parameter Press Num of Steps to open the number of steps pa rameter Open the parameter you wish to change then edit the current value using the cursor control key or ro tary data knob or enter a new value using the key pad and appropriate termination key When yo...

Page 64: ...he trigger key is pressed If a sweep is in pro gress when the key is pressed it aborts and re sets To go to the CW Level Sweep Trigger menu shown below from the CW Level Sweep Ramp menu press Trigger Menu To select a CW power sweep trigger mode press its menu soft key A message showing the CW power sweep trigger mode selected appears on the right side of the level mode title bar If you select the ...

Page 65: ...rent power level sweep range start by opening either the start or stop power level pa rameter in the display above Edit L1 opens the start power level parameter Edit L2 opens the stop power level parameter Edit the open power level parameter using the cur sor control key or the rotary data knob When you are finished close the open parameter by pressing its menu edit soft key or by making another m...

Page 66: ...ters for each preset sweep range Setting a Preset Power Level Sweep Range At the Level Sweep Control menu select the power level sweep range L1 L2 L3 L4 L5 L6 L7 L8 or L9 L0 that you wish to set The menu then displays the current frequency parameters for the selected power level sweep range Now use the menu edit soft keys to open the power level parameters for ed iting Edit the current power level...

Page 67: ...elect an analog sweep frequency step power mode start with an analog sweep menu display to select a step sweep frequency step power mode start with a step sweep menu display Then press the main menu key LEVEL ALC SELECT At the resulting menu display press Lvl Swp The Level Sweep Menu is displayed This menu lets you perform the following Select a power level sweep range edit the sweep start and sto...

Page 68: ...ress Sweep Ramp This menu lets you set the step size and the number of steps Press Step Size to open the step size parameter Press Num of Steps to open the number of steps pa rameter Open the parameter you wish to change then edit the current value using the cursor control key or ro tary data knob or enter a new value using the key pad and appropriate termination key When you have finished setting...

Page 69: ...de of the RF output changes linearly as the exter nal AM input changes In Log AM mode sensitivity is 10 dB V and the sweep generator accepts a wider range of input sig nals from the external signal generator For every 1V input the RF output level decreases by 10 dB for every 1V input the RF output level increases by 10 dB The dynamic range of the of positive or negative power levels depends on the...

Page 70: ...ut connector Press On Off to turn AM on and off Both the AM status display and AM modulation status area will reflect your selection Press Log Linear to select the AM operating mode The AM status display will reflect your selection as 10 dB V Log or 100 V Linear Press Front Rear to select the front panel or rear panel AM IN connector The AM status display will reflect your selection Press 600Ω 50Ω...

Page 71: ...de allows maximum deviations of 50 MHz In Wide mode the FM signal is synthesized by ap plying the modulating signal to the main tuning coil of the YIG tuned oscillator Wide FM mode allows maximum deviations of 100 MHz Providing Frequency Modulation To provide frequency modulation first set up the ex ternal signal generator then connect it to either the 681XXA front or rear panel FM IN connector Ne...

Page 72: ...select the front or rear panel FM IN connector The FM status display will reflect you selection Press 600Ω 50Ω to select the input impedance of the input connector The FM status display will re flect your selection To select the FM sensitivity necessary to obtain the desired deviation press Sens As shown below the menu display then lists the FM sensitivity choices Use the cursor control key to cho...

Page 73: ...ing are the menu selections necessary to provide square wave pulse modulation of the out put signal using a modulating signal from both the internal and external sources Press MODULATION At the resulting menu dis play press SqWave The Square Wave Status Menu shown below is displayed This menu contains the square wave status window that shows the current menu selections This menu lets you perform t...

Page 74: ...ich input connector is selected Press L RF On H RF On to select the polarity of the signal that triggers the RF on Press More to go to the additional menu Internal Source Frequency Selection If you have selected Internal to use the modulating signal from the internal source then when you press More the menu shown below is displayed Use the cursor control key to chose the desired modulating signal ...

Page 75: ... then when you press More the menu shown below is displayed Press Front Rear to select the front or rear panel IN connector The Square Wave status dis play shows your selection as Source Press Previous Menu to return to the initial Square Wave Status Menu display LOCAL FRONT SIGNAL PANEL OPERATION MODULATION 681XXA OM 3 53 ...

Page 76: ...e Setups Menu shown be low is displayed Press Save then enter the desired setup number between 0 and 9 on the keypad The setup is now saved NOTE Setup 0 automatically saves the current front panel settings upon instrument shutdown Therefore it is recommended that you use only setups 1 through 9 to save front panel setups Recalling Setups To recall a previously saved setup first access the Setups M...

Page 77: ...ecure mode and how to return to normal op eration To place the 681XXA in the secure mode first press SYSTEM to display the System Menu Next press Secure This places the sweep gener ator in the secure mode and the Secure Menu shown below is displayed NOTE During secure mode all main menu keys and menu soft keys operate normally The menu soft key labels are displayed and change with menu selections ...

Page 78: ...power slope and decouple functions Use the Level ing Modes menu map Chapter 4 Figure 4 12 to follow the menu se quences Selecting a Leveling Mode Output power leveling is controlled by the ALC sys tem It is a feedback control system in which the output power is measured at a detector and com pared with the expected power level If the output and desired power levels do not equal the ALC ad justs th...

Page 79: ...menu To go to the Leveling Menu from the ALC Mode menu press Leveling Menu The Leveling Menu shown below is displayed To select internal ALC press Internal Pressing one of the other leveling menu soft keys External Detector Power Meter or Fixed Gain will turn off internal leveling Press Previous Menu to return to the ALC Mode menu External Leveling In external leveling the output power from the 68...

Page 80: ...ut from an external detector press External Detector To select the external ALC input from a power me ter press Power Meter After you have made the external ALC input connec tion and selected the sensor type press ALC Loop The ALC Loop Menu shown below is displayed Press Ext ALC Gain to set the external ALC Gain While monitoring the power level at the external de tection point use the cursor contr...

Page 81: ...installed are used to control the relative power level Power is not detected at any point and the absolute power level is uncalibrated Fixed gain mode is selected from the leveling menu Press Leveling Menu to go to the Leveling menu To select fixed gain mode press Fixed Gain To return to normal ALC operation press Internal Press Previous Menu to return to the ALC Mode menu LOCAL FRONT LEVELING PAN...

Page 82: ...shown below is displayed This menu lets you decouple the step attenuator from the ALC set the power level and set the at tenuation in 10 dB steps Press Decouple to decouple the step attenuator from the ALC Press Edit L1 to open the power level parameter for editing Edit the current level using the cursor con trol key or rotary data knob or enter a new value us ing the key pad and appropriate termi...

Page 83: ...oth the power slope and the pivot point The ALC loop menu lets you activate the ALC power slope function To go to the ALC Loop Menu from the Level ALC Control Menu display press ALC Loop The ALC Loop Menu shown below is displayed This menu lets you turn the power slope on or off and edit the slope value and pivot point frequency LOCAL FRONT LEVELING PANEL OPERATION OPERATIONS Power Slope Power at ...

Page 84: ...for ed iting Edit the current slope value using the cursor control key or rotary data knob or enter a new value using the key pad and the STEPS termination key When you have finished setting the open parameter close it by pressing Edit Slope again or by making another menu selection While monitoring the power level at the device un der test DUT adjust the power slope and pivot point to level the p...

Page 85: ... terminator and incre ment sizes for frequency power level and time parameters Use the System Configuration menu map Chapter 4 Figure 4 13 to follow the menu sequences To go to the System Configuration menu first press SYSTEM At the System Menu display press Config The System Configuration Menu shown below is displayed This menu lets you go to the Front Panel Rear Panel RF GPIB and Increment Confi...

Page 86: ...rom the System Configuration menu press Front Panel The Configure Front Panel Menu shown below is displayed Press Brite repeatedly to increase the intensity of the data display to the desired level Press Dim repeatedly to decrease the intensity of the data display When done press Previous Menu to return to the System Configuration menu LOCAL FRONT SYSTEM PANEL OPERATION CONFIGURATION 3 64 681XXA O...

Page 87: ...RETRACE BLANK OUT connector The display will reflect your selection Press Penlift to select normally open N O or nor mally closed N C contacts on the internal penlift relay The penlift relay output available at the rear panel PEN LIFT OUT connector is used to lift a plot ter pen during retrace The display will reflect your selection Press Marker to select a 5V or 5V level for the video marker outp...

Page 88: ...F to select RF On or Off during re trace The display will reflect your selection Press Delta F RF to select RF On or Off during fre quency switching in CW or step sweep modes The display will reflect your selection Press Ramp Rest to select 0 or 10 for the ramp rest point for sweeps triggered a single or external trig ger 0 indicates that the sweep will rest at the bot tom of the sweep ramp 10 ind...

Page 89: ...sizer s default GPIB address is 5 Enter a new address between 1 and 30 using the cursor control key or the data en try keypad and the terminator key Hz ns ADRS The new GPIB address will appear on the display Press Line Term to select a carriage return CR or a carriage return and line feed CR LF as the GPIB data delimiter Consult the GPIB controller s man ual to determine which data delimiter is re...

Page 90: ...s displayed Press Freq Incr to open the frequency increment pa rameter Press Level Incr to open the power level increment parameter Press Time Incr to open the time increment parame ter Open the parameter you wish to change then edit the current value using the cursor control key or ro tary data knob or enter a new value using the key pad and appropriate termination key When you have finished sett...

Page 91: ...1XXAs shown in Figure 3 4 as follows 1 Connect the interface cable end labeled Master to the rear panel AUX I O connector on the Mas ter 681XXA Connect the interface cable end la beled Slave to the rear panel AUX I O on the Slave 681XXA 2 Connect the rear panel 10 MHz REF OUT connec tor on the Master 681XXA to the rear panel 10 MHz REF IN connector on the Slave 681XXA us ing a coax cable 3 Connect...

Page 92: ... on each Both units now display the System Menu shown below e On the Master 681XXA press Master on the Slave 681XXA press Slave f Return both sweep generators to CW mode by pressing the main menu key CW SWEEP SELECT g Now press Analog to place both sweep gener ators in analog sweep mode This starts mas ter slave operation Resynchronizing after Parameter Changes In analog sweep frequency mode any p...

Page 93: ... d On the Slave sweep generator select the same number of steps as the Master e When finished press CW on both sweep gen erators to place them in CW mode then press SYSTEM on each Both units now display the System Menu shown below f On the Master 681XXA press Master on the Slave 681XXA press Slave g Return both sweep generators to CW mode by pressing the main menu key CW SWEEP SELECT h Now press S...

Page 94: ...t frequency output sig nals after making a parameter change on the Slave 681XXA first put the Master 681XXA in CW mode then place it back in step sweep mode If you change the number of steps in the step sweep on either sweep generator you must select the same number of steps on the other sweep generator To re start resynchronize master slave operation put the Master 681XXA in CW mode then place it...

Page 95: ...Table of Contents 4 1 INTRODUCTION 4 3 4 2 MENU MAP DESCRIPTION 4 3 Chapter 4 Local Operation Menu Maps ...

Page 96: ...f each menu s soft keys is provided If a menu soft key se lects another menu then it is shown linked to that menu Figure 4 1 on page 4 5 is a sample menu map annotated to identify the key ele ments The following is a list of the menu maps contained in this chapter Figure Title Page 4 1 Sample Menu Map 4 5 4 2 CW Frequency Mode Menu Map 4 6 4 3 Analog Sweep Frequency Mode Menu Map 4 7 4 4 Step Swee...

Page 97: ...ent Power Level CW Ramp On Off Set The Sweep Time Typical Menu Soft Key Functional Description Points To The Menu Displayed Whenever The Menu Soft Key Is Depressed A Main Menu Display Main Menu Key Cursor Indicates The Active Main Menu Key Indicates That Pressing This Main Menu Key While In The Current Mode Displays The Parameter Control Menu Main Menu Key Cursor Note In Most Cases Pressing a Menu...

Page 98: ...QUENCY CONTROL LEVEL ALC SELECT LEVEL CONTROL Output Previous Tagged Frequency Edit Current Frequency Tag Untag Highlighted Frequency Edit Highlighted Frequency Output Highlighted Frequency Output Next Tagged Frequency Edit Current Power Level Edit Current Frequency Edit Current Power Level Edit Current Power Level On Off Set The Sweep Time Figure 4 2 CW Frequency Mode Menu Map ...

Page 99: ...Start Frequency Edit End Frequency Edit Current Sweep Time On Off On Off On Off On Off On Off On Off Edit Start Frequency Edit End Frequency Edit Current Power Level Tag Untag Highlighted Marker Frequency Edit Highlighted Marker Frequency On Off On Off Can Be Selected From Any Analog Menu Display Triggers Single Sweep Edit Alt Sweep Power Level LOCAL OPERATION ANALOG SWEEP MENU MAPS FREQUENCY MODE...

Page 100: ...d Frequency Edit Dwell Time N A On Off On Off On Off On Off On Off Edit Step Size Edit Number of Steps Edit Start Frequency Edit End Frequency Edit Current Power Level Tag Untag Highlighted Marker Frequency Edit Highlighted Marker Frequency N A On Off Can Be Selected From Any Step Sweep Menu Display Edit Alt Sweep Start Frequency Edit Alt Sweep Stop Frequency Edit Main Sweep Power Level Edit Alt S...

Page 101: ...Y CONTROL LEVEL ALC SELECT LEVEL CONTROL SYSTEM MODULATION CW SWEEP SELECT FREQUENCY CONTROL LEVEL ALC SELECT LEVEL CONTROL Edit Start Frequency Edit End Frequency Edit Start Frequency Edit End Frequency Edit Current Power Level Edit Step Size Edit Number of Steps Figure 4 5 Manual Sweep Frequency Mode Menu Map ...

Page 102: ...CT FREQUENCY CONTROL LEVEL ALC SELECT LEVEL CONTROL Output Previous Tagged Power Level Edit Current Power Level Tag Untag Highlighted Power Level Edit Highlighted Power Level Output Highlighted Power Level Output Next Tagged Power Level Edit Power Level Offset On Off Level Offset Edit Current Power Level Display Showing Level Offset On Figure 4 6 Fixed Power Level Mode Menu Map ...

Page 103: ...LEVEL ALC SELECT LEVEL CONTROL SYSTEM MODULATION CW SWEEP SELECT FREQUENCY CONTROL LEVEL ALC SELECT LEVEL CONTROL On Off Edit Step Size Edit Dwell TIme On Off On Off Edit Number of Steps Edit End Power Level Edit Start Power Level Edit End Power Level Edit Start Power Level Figure 4 7 CW Power Sweep Mode Menu Map ...

Page 104: ... Mode Menu Map SYSTEM MODULATION CW SWEEP SELECT FREQUENCY CONTROL LEVEL ALC SELECT LEVEL CONTROL SYSTEM MODULATION CW SWEEP SELECT FREQUENCY CONTROL LEVEL ALC SELECT LEVEL CONTROL Edit Start Power Level Edit End Power Level Edit Start Power Level Edit End Power Level N A Edit Step Size N A Edit Number of Steps ...

Page 105: ...CY CONTROL LEVEL ALC SELECT LEVEL CONTROL SYSTEM MODULATION CW SWEEP SELECT FREQUENCY CONTROL LEVEL ALC SELECT LEVEL CONTROL Log AM 10dB V or Linear AM 100 V Front Panel Input or Rear Panel Input 600Ω or 50Ω Input Impedance AM On Off Display Showing AM Selected On Figure 4 9 Amplitude Modulation Mode Menu Map ...

Page 106: ...EL ALC SELECT LEVEL CONTROL SYSTEM MODULATION CW SWEEP SELECT FREQUENCY CONTROL LEVEL ALC SELECT LEVEL CONTROL FM On Off Wide FM Mode or Narrow FM Mode 600Ω or 50Ω Input Impedance Select Sensitivity Display Showing FM Selected On Unlocked Front Panel Input or Rear Panel Input Figure 4 10 Frequency Modulation Mode Menu Map ...

Page 107: ... ROL Internal Square Wave Source or External Square Wave Source LOW Level Triggers RF or HIGH Level Triggers RF Select Frequency Square Wave Modulation On Off Internal Square Wave Source or External Square Wave Source LOW Level Triggers RF or HIGH Level Triggers RF Square Wave Modulation On Off Front Panel Input Rear Panel Input Internal Square Wave Source Selected External Square Wave Source Sele...

Page 108: ...ttenuation 10dB Steps Press To Decrease Attenuation 10dB Steps ALC Slope On Off Edit The ALC Slope Edit The Pivot Point Selects Front Panel External ALC Input Selects Rear Panel External ALC Input Set The External ALC Input Gain Selects Internal ALC Default Mode Selects External ALC External Detector Input Selects External ALC Power Meter Input Selects ALC Off Figure 4 12 Leveling Modes Menu Map L...

Page 109: ... Address Select CR or CR LF Line Terminator Brightens The Display Dims The Display Select RF On or Off During Retrace Select Reset For Single Sweep 0 For Bottom of Sweep Ramp 10 For Top of Sweep Ramp Select RF On or Off During Frequency Switching In CW and Step Modes Select 5V or 5V Level For Retrace and Bandswitch Blanking Set Frequency Increment Set Power Level Increment Increment Mode On Off Se...

Page 110: ...HECKOUT 5 4 Power Up 5 4 Self Test 5 4 Resetting the 681XXA 5 4 Warmup Time 5 4 5 5 CW FREQUENCY ACCURACY TEST 5 5 Test Setup 5 5 Test Procedure 5 6 5 6 POWER LEVEL TESTS 5 9 Test Setup 5 9 Power Level Accuracy Test Procedure 5 10 Power Level Flatness Test Procedure 5 11 Chapter 5 Operation Verification ...

Page 111: ...tocopied and used to record the results of operational verification testing of your 681XXA These tables are included as part of the operational verifica tion test procedures and contain test information for all 681XXA mod els Instrument Critical Specification Recommended Manufacturer Model Frequency Counter with External Mixer Range 0 01 to 40 GHz Input Z 50Ω Resolution 1 Hz Other External Time Ba...

Page 112: ...e instrument PCBs and other internal assemblies To self test the signal generator press SYSTEM Then press the System Menu soft key Selftest When the self test is complete the sweep generator displays the main CW menu NOTE Error conditions detected during self test are displayed as error messages on the data display They should be corrected before con tinuing Refer to Chapter 6 for a listing of err...

Page 113: ...Frequency Counter has an INT EXT toggle switch ensure the switch is set to EXT 2 Connect the 681XXA RF OUTPUT to the Fre quency Counter RF Input as follows a For measuring frequencies of 0 01 to 1 0 GHz connect to the Band 2 input Connection A b For measuring frequencies of 1 0 to 26 5 GHz connect to the Band 3 input Connection A c For measuring frequencies of 26 5 to 40 0 GHz connect to the Band ...

Page 114: ...pecifications 100 Hz of the value shown on the test record for standard models 10 Hz for instru ments with Option 11 3 Record the Frequency Counter reading on the test record Table 5 2A or Table 5 2B NOTE The Frequency Counter reading is typically within 1 Hz because the instruments use a common time base Differences of a few Hertz can be caused by noise or counter limitations Differences of 100 H...

Page 115: ..._____________________ _____________________ _____________________ 2 000 001 000 2 000 002 000 2 000 003 000 2 000 004 000 2 000 005 000 2 000 006 000 2 000 007 000 2 000 008 000 2 000 009 000 2 000 010 000 _____________________ _____________________ _____________________ _____________________ _____________________ _____________________ _____________________ _____________________ __________________...

Page 116: ...____________________ _____________________ _____________________ 2 000 000 100 0 2 000 000 200 0 2 000 000 300 0 2 000 000 400 0 2 000 000 500 0 2 000 000 600 0 2 000 000 700 0 2 000 000 800 0 2 000 000 900 0 2 000 001 000 0 _____________________ _____________________ _____________________ _____________________ _____________________ _____________________ _____________________ _____________________...

Page 117: ... 1 Calibrate the Power Meter with the Power Sensor 2 Connect the Power Sensor to the RF OUTPUT of the 681XXA 3 Connect the 681XXA rear panel HORIZ OUT to the Oscilloscope CH 1 input X input NOTE Before starting these procedures locate the test record in Table 5 3 for the particular 681XXA model configuration being tested RF OUT HORIZ OUT 681XXA SWEEP GENERATOR OSCILLOSCOPE Power Sensor POWER METER...

Page 118: ... to open the current power level parameter for editing e Set L1 to the power level noted on the test re cord 2 Measure the output power level with the Power Meter and record the reading on the test record 3 Verify that the Power Meter reading meets the specifications stated on the test record 4 Set L1 to the next test power level Record the Power Meter reading on the test record 5 Repeat step 4 fo...

Page 119: ... CW Menu is displayed b Press Step to place the 681XXA in the step sweep frequency mode and display the Step Sweep Menu shown below c With the Step Sweep menu displayed press the main menu key FREQUENCY CONTROL The Sweep Frequency Control menu shown be low is displayed d Press Full to select a full range frequency sweep e Press Edit L1 to open the current power level parameter for editing f Set L1...

Page 120: ...to 1 second NOTE Monitor the 681XXA s Horizontal Output on the Oscilloscope to determine sweep start and stop 2 As the 681XXA steps through the full frequency range measure the maximum and minimum Power Meter readings and record the values on the test record Verify that the variation differ ence between the maximum and minimum read ings does not exceed the value noted on the test record OPERATION ...

Page 121: ... With the Analog Sweep menu displayed press the main menu key FREQUENCY CONTROL The Sweep Frequency Control menu shown be low is displayed d Press Full to select a full range frequency sweep e Press Edit L1 to open the current power level parameter for editing f Set L1 to the power level noted on the test re cord g Now return to the Analog Sweep menu by pressing the main menu key CW SWEEP SELECT O...

Page 122: ...nitor the 681XXA s Horizontal Output on the Oscilloscope to determine sweep start and stop 4 During the analog sweep measure the maximum and minimum Power Meter readings and record the values on the test record Verify that the vari ation difference between the maximum and mini mum readings does not exceed the value noted on the test record OPERATION POWER LEVEL ACCURACY VERIFICATION AND FLATNESS T...

Page 123: ...Bm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm Specification is 1 0 dB Power Level Flatness Step Sweep Set Power Max Power Min Power Variation 13 dBm _________dBm __________dBm _________dB Maximum variation is 1 6 dB Power Level Flatness Analog Sweep Set Power Max Power Min Power Variation 13 dBm _________dBm ___...

Page 124: ..._________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm Specification is 1 0 dB Power Level Flatness Step Sweep Set Power Max Power Min Power Variation 10 dBm _________dBm __________dBm _________dB Maximum variation is 1 6 dB Power Level Flatness Analog Sweep Set Power Max Power Min Power Variation 10 dBm _________dBm ______...

Page 125: ..._______dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm Specification is 1 0 dB Power Level Flatness Step Sweep Set Power Max Power Min Power Variation 17 dBm _________dBm __________dBm _________dB Maximum variation is 1 6 dB Power Level Flatness Analog Sweep Set Power Max Power Min Power Variation 17...

Page 126: ...____dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm Specification is 1 0 dB Power Level Flatness Step Sweep Set Power Max Power Min Power Variation 14 dBm _________dBm __________dBm _________dB Maximum variation is 1 6 dB Power Level Flatness Analog Sweep Set Power Max Power Min Power Variation 14 dB...

Page 127: ...Bm _________dBm _________dBm 13 dBm 12 dBm 11 dBm 10 dBm 9 dBm 8 dBm 7 dBm 6 dBm 5 dBm 4 dBm 3 dBm 2 dBm 1 dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm Specification is 1 0 dB Specification is 1 0 dB Power Level Flatness Step Sweep Set Power Max Power Min Power Variation ...

Page 128: ...m _________dBm _________dBm 10 dBm 9 dBm 8 dBm 7 dBm 6 dBm 5 dBm 4 dBm 3 dBm 2 dBm 1 dBm 0 dBm 1 dBm 2 dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm Specification is 1 0 dB Specification is 1 0 dB Power Level Flatness Step Sweep Set Power Max Power Min Power Variation 10 d...

Page 129: ...____dBm _________dBm _________dBm _________dBm 17 dBm 16 dBm 15 dBm 14 dBm 13 dBm 12dBm 11 dBm 10 dBm 9 dBm 8 dBm 7dBm 6 dBm 5 dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm Specification is 1 0 dB Specification is 1 0 dB Power Level Flatness Step Sweep Set Power Max Power ...

Page 130: ...__dBm _________dBm _________dBm _________dBm 14 dBm 13 dBm 12 dBm 11 dBm 10 dBm 9 dBm 8 dBm 7 dBm 6 dBm 5 dBm 4 dBm 3 dBm 2 dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm Specification is 1 0 dB Specification is 1 0 dB Power Level Flatness Step Sweep Set Power Max Power Min...

Page 131: ...m _________dBm 6dBm 5 dBm 4 dBm 3 dBm 2dBm 1 dBm 0 dBm 1 dBm 2 dBm 3 dBm 4 dBm 5 dBm 6 dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm Specification is 1 0 dB Specification is 1 0 dB Power Level Flatness Step Sweep Set Power Max Power Min Power Variation 6 dBm _________dBm _...

Page 132: ..._________dBm 2 dBm 1 dBm 0 dBm 1 dBm 2 dBm 3 dBm 4 dBm 5 dBm 6 dBm 7 dBm 8 dBm 9 dBm 10 dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm Specification is 1 0 dB Specification is 1 0 dB Power Level Flatness Step Sweep Set Power Max Power Min Power Variation 2 dBm _________dBm ...

Page 133: ... _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm 6dBm 5 dBm 4 dBm 3 dBm 2dBm 1 dBm 0 dBm 1 dBm 2 dBm 3 dBm 4 dBm 5 dBm 6 dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dB...

Page 134: ... _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm 2 dBm 1 dBm 0 dBm 1 dBm 2 dBm 3 dBm 4 dBm 5 dBm 6 dBm 7 dBm 8 dBm 9 dBm 10 dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm _________dBm ________...

Page 135: ...US MESSAGES 6 3 Self Test Error Messages 6 3 Normal Operation Error and Warning Status Messages 6 8 6 3 TROUBLESHOOTING 6 10 6 4 ROUTINE MAINTENANCE 6 13 Replacing a Fuse 6 13 Cleaning the Fan Filter 6 14 Cleaning the Data Display 6 14 Chapter 6 Operator Maintenance ...

Page 136: ...nostics that self test the instrument These self test diagnos tics perform a brief go no go test of most of the in strument PCBs and other internal assemblies You can perform a sweep generator self test at any time during normal operation by pressing SYSTEM and then the System Menu soft key Selftest If the sweep generator fails self test an error mes sage s is displayed on the front panel data dis...

Page 137: ...reached operating temperature The 681XXA is still operable but frequency accuracy and stability may be degraded Error 109 The 100MHz Reference is not Locked to the External Reference Indicates the reference loop is not phase locked to the external 10 MHz reference The reference loop may phase lock to the internal 100 MHz time base consequently the 681XXA would continue to operate normally Error 11...

Page 138: ...ot leveled detector circuitry on the A10 PCB The 681XXA is still operable but a warning message will not appear when the RF output goes unleveled Error 122 Level Reference Failed Indicates a failure of the level reference circuitry on the A10 PCB Use caution and always determine the output power level when operating the 681XXA in this condition Error 123 Detector Log Amp Failed Indicates a failure...

Page 139: ... always determine the output power level when operating the 681XXA in this condition Error 134 13 25 20 GH Switched Filter Indicates a failure of the 13 25 20 GHz switched filter The 681XXA may or may not produce an RF output in this frequency range Use caution and always determine the output power level when operating the 681XXA in this condition Error 135 Modulator or Driver Failed Indicates a f...

Page 140: ... hold circuitry on the A10 PCB The 681XXA still operates normally but the RF output may be unleveled during square wave modulation Error 143 Slope DAC Failed Indicates a failure of the level slope DAC on the A10 PCB The 681XXA still operates normally but RF output level flatness may be affected during analog frequency sweeps Error 144 RF was Off when Selftest started Some tests were not performed ...

Page 141: ...splayed in the frequency parameters area when the output frequency is not phase locked The frequency accuracy and stability of the RF output is greatly reduced Normally caused by an internal component failure Run self test to verify malfunction RANGE ERR Displayed in the frequency parameters area when 1 the sweep start frequency entered is greater than the stop frequency 2 the F value entered resu...

Page 142: ...d only when AM is selected ON the modulating signal may be driving the RF output unleveled Reducing the modulating signal or adjusting the power level usually clears the warning UNLOCKED When FM is selected ON this warning message appears indicating that the instrument is not phase locked during the FM mode of operation EXT REF This status message indicates that an external 10 MHz signal is being ...

Page 143: ...der is defective replace see page 6 13 If they are good go to the next step Step 2 Check to see if power is available at the power receptacle If not move to a working receptacle If power is available go to the next step Step 3 Check the power cable If defective replace If good call a service technician Sweep Generator will not turn on OPERATE light is ON Normal Operation When the 681XXA is connect...

Page 144: ... operating clean the air filter see page 6 14 If the fan is not operating call a service technician One or More Error Messages are Displayed During Start Up Step 1 Perform a self test of the sweep generator by pressing the System Menu soft key Selftest If error message s does not repeat resume normal opera tion If error message s remains call a service technician LOCK ERROR is Displayed Step 1 Per...

Page 145: ... displayed call a service techni cian RANGE ERR is Displayed Step 1 Check that 1 the sweep start frequency entered is not greater than the stop frequency 2 the dF value entered does not try to set the frequency sweep outside the range of the sweep generator or 3 the step size entered is not greater than F2 minus F1 Enter a valid sweep start frequency dF value or step size If the error message rema...

Page 146: ...plug it from the line voltage module 2 Insert the blade of a small screwdriver into the slot at the top center of the line voltage module and pry open the cover 3 Grasp the fuse holders and pull them out Figure 6 1 4 Remove the fuses from the fuse holders 5 Check the fuses and replace any that have failed 6 Install the fuse holders back into the module then close the cover Ensure the desired volta...

Page 147: ... or by rinsing in warm water then dry ing 4 Install the fan filter and four knurled nuts 5 Tighten the knurled nuts securely Cleaning the Data Display The data display of the sweep generator is protected by a plastic display filter To clean the display filter use mild soap or detergent and water or a commer cial window cleaner When cleaning use a soft lint free cloth Do not use abrasive cleaners t...

Page 148: ...ies 681XXA Synthesized Sweep Generator A 2 REAR PANEL CONNECTORS Figure A 1 provides a illustration of the rear panel and describes the rear panel connectors A 3 CONNECTOR PINOUT DIAGRAMS Figures A 2 and A 3 provide pinout diagrams and descriptions for the AUX I O and IEEE 488 GPIB multipin connectors on the rear panel 681XXA OM A 1 ...

Page 149: ...nd a 10V se lected marker pulse during forward sweep BNC connector HORIZ OUT Provides a 0V to 10V ramp during all sweep modes regardless of sweep width In the CW mode provides a voltage between 0V and 10V proportional to the full frequency range of the instrument When the CW Ramp is enabled provides a repetitive 0V to 10V ramp BNC connector 50Ω impedance 10 MHz REF IN Accepts an external 10 MHz 10...

Page 150: ...s to two RS 232 terminal ports to support service and calibration functions RJ45 connector DWELL IN Accepts an external TTL low level signal to stop the sweep in both analog and step sweep modes The sweep resumes when the signal is removed V GHz OUT Provides a reference voltage rela tive to the frequency of the RF output see table below BNC connector PEN LIFT OUT Provides relay contacts for liftin...

Page 151: ...NG Retrace Blanking Output Provides a 5V or 5V signal coincident with sweep retrace Signal polarity selected from a front panel menu 7 L ALT SWP L Alternate Sweep Output Provides a TTL low level signal which indicates that the primary sweep is in progress or a TTL high level signal which indicates that the alternate sweep is in progress 8 Shield Cable Shield Chassis Ground 9 TRIGGER OUTPUT Trigger...

Page 152: ... and step sweep modes The sweep resumes when the signal is removed 19 AUX 2 Aux 2 Auxiliary input output to the processor PC3 20 BANDSWITCH BLANK Bandswitch Blanking Output Provides a 5V or 5V signal coincident with bandswitching points Signal polarity is selected from a front panel menu 21 SPARE 22 HORIZ IN Horizontal Sweep Input Accepts a 0V to 10V external sweep ramp from a Master sweep generat...

Page 153: ...rs have accepted the current data byte for internal processing 9 IFC Interface Clear A low true state places all bus instruments in a known quiescent state unaddressed to talk unaddressed to listen and service request idle 10 SRQ Service Request A low true state indicates that a bus instrument desires the immediate attention of the controller 11 ATN Attention A low true state indicates that the bu...

Page 154: ...Steps User selectable number of steps or the step size Number of Steps Variable from 1 to 10 000 Step Size 1 kHz 0 1 Hz with Option 11 to the full fre quency range of the instrument If the step size does not divide into the selected frequency range the last step is truncated Dwell Time Per Step Variable from 1 ms to 99 seconds Switching Time typical maximum 5 ms 3 ms GHz step size or 25 ms whichev...

Page 155: ...SIDUAL FM Analog Sweep and FM modes 50 Hz 15 kHz BW AM Noise Floor Typically 145 dBm Hz at 0 dBm output and offsets 5 MHz from carrier RF OUTPUT Power level specifications apply at 25 10 C MAXIMUM LEVELED OUTPUT POWER LEVELED OUTPUT POWER RANGE Without an Attenuator Maximum leveled power to 15 dBm 20 dBm overrange With an Attenuator Maximum leveled power to 125 dBm 130 dBm overrange UNLEVELED OUTP...

Page 156: ...location Accepts a positive or negative 0 5 mV to 500 mV input signal from the remote detector EXT ALC GAIN adjusts the input signal range to an optimum value BNC connector front and rear panel External Power Meter Levels output power at a re mote power meter location Accepts a 1V full scale input signal from the remote power meter EXT ALC GAIN ad justs the input signal range to an optimum value B...

Page 157: ...nput Front or rear panel BNC selectable from modulation menu Drive Level TTL compatible input Minimum Pulse Width 5 µs Input Logic Positive true or negative true selectable from modulation menu REMOTE OPERATION All instrument functions settings and operating modes ex cept for power on standby are controllable using commands sent from an external computer via the GPIB IEEE 488 interface bus GPIB Ad...

Page 158: ...ition over the cursor Controlled parameters are frequency power level sweep time dwell time and number of steps Keypad entries are terminated by pressing the appropriate unit key GHz Sec dBm MHz ms dB kHz µs STEPS or Hz ns ADRS Edits are terminated by exiting the edit menu Master Reset Returns all instrument parameters to prede fined default states or values Any pending GPIB I O is aborted Selecta...

Page 159: ...TRACE BLANK OUT Provides a 5V or 5V signal co incident with sweep retrace Signal polarity selectable from system menu SEQ SYNC OUT Sequential Sync Output Provides a 5V signal during retrace at bandswitching points and dur ing each frequency step in step sweep mode 5V during markers and 10V during the selected marker DWELL IN Accepts an external TTL low level signal to pause the sweep in both analo...

Page 160: ...ector K Connector female to the rear panel and de letes the RF output connector on the front panel Option 11 0 1 Hz Frequency Resolution Provides fre quency resolution of 0 1 Hz Option 14 WILTRON 360B VNA Compatibility Modifies rack mounting hardware to mate unit in a WILTRON 360B VNA console Option 15 High Power Output Adds high power RF components to the instrument providing 50 mW RF output powe...

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