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Tektronix Hunting Equipment 7934 User's Manual

1. LEFT VERT CHANNEL 2 RIGHT VERAT CHANNEL 2 A HORIZ CHANNEL 2 B HORIZ CHANNEL 2 1987 4 Figure 2 4 Location of readout on the crt identifying the origi nating plug in and channel The reduced scan mode changes the location of the readout display Figure 2 5 shows the correct readout loca tion for the reduced scan mode Notice that the readout display is positioned outside the half size inner graticule and that the location of the readout words is directly related to the plug in unit and channel from which they originated Usually the readout information for plug in units and or channels which are selected by the mode switches appear in the readout display Some special purpose plug in units may over ride the mode switches to display readout even though the compartment is not selected for display Readout identify An identify feature is provided by the Readout System to correlate the readout word with the originating plug in unit and channel amplifier units only When the identify button of an amplifier unit is pressed the word IDENTIFY appears in the readout location allocated to that plug in and channel Other readout words in the display remain unchanged When the identify button is released the readout display from this plug in channel is again displayed Circuitry may also be provided in the amplifier unit to produce a noticeable change in the analog waveform display to identify the asso ciated tr
2. Amplifier B Real time Time base C Curve Tracer D Digital Unit L Spectrum Analyzer M Miscellaneous S Sampling Unit T Sampling Time base The third and fourth digits of the plug in type number carry no special connotation An N suffix letter added to the normal four digit type number means that the instrument does not have the cir cuitry necessary to encode data for the 7000 series readout system Table 1 7 lists any incompatibilities between the 7934 and the variety of plug in units available Table 1 8 lists the vertical specifications which are sys tem dependent For more complete specifications on vertical plug in units for the 7934 Oscilloscope system refer to the current Tektronix Products Catalog Table 1 9 lists the horizontal specifications which are system dependent For more complete specifications on horizontal plug in units for the 7934 Oscilloscope system refer to the current Tektronix Products Catalog Table 1 10 lists some of the special purpose plug in units that can be used with the 7934 Oscilloscope 1 13 Generai Information 7934 Operators Table 1 7 PLUG IN INCOMPATIBILITIES The 7934 Oscilloscope is compatible with Tektronix 7000 Series Plug In units with the exceptions listed in the following table Plug in Unit Operating Conditions Symptoms Cause 7A21N 7B50 7B51 7B52 7B53A 7B53AN 7B53N 7B50 HS 7B70 7B71 7851 7B71 7B85 7B85 7B
3. Directly Gated Counter Universal Counter Timer Programmable Digitizer CATV Preamplifier 20 Hz to 5 MHz Spectrum Analyzer 100 kHz to 1 7 GHz Spectrum Analyzer 1 kHz to 1 8 GHz Spectrum Analyzer 10 kHz to 1 8 GHz Spectrum Analyzer 1 5 GHz to 60 GHz Spectrum Analyzer Dual 50 Ohm Delay Line Readout Access Unit Accepts Plug In Sampling Heads Time Domain Reflectometer and Sampling Applications Dual Trace Delay Sweep Sampler Random or Sequential Equivalent or Real Time Sampling Time Base General Information 7934 Operators STANDARD ACCESSORIES Operators Manual 1 each Instruction Manual 1 each Gray Faceplate Protector installed 1 each Storage Green Faceplate Filter 1 each Power Cord 1 each 070 5879 00 070 5880 00 378 0625 02 378 0625 08 161 0066 00 RECOMMENDED ACCESSORIES not included The following accessories are available for use with the 7934 Oscilloscope For more information or to order recom mended accessories contact your local Tektronix Field Of fice or representative Current Loop Probe Adapter Camera Low Cost General Purpose Camera For Automatic Single Sweep Photos Tek Lab Cart 012 0341 00 C 5A C 52 Model 3 Section 2 7934 Operator s OPERATING INSTRUCTIONS To operate the 7934 effectively the user must become familiar with its operation and capabilities This section de scribes how to use the front and rear panel controis and connectors For detailed operating
4. Negative going signals increase the display in tensity and positive going signals decrease the display intensity Refer to Table 1 4 in the General Information section for specifications on Z axis signal requirements Time markers applied to the rear panel Z AXIS INPUT connector can provide direct time reference on the display With uncalibrated horizontal sweep or X Y mode operation the time markers provide a means of reading time directly from the display If the markers are not time related to the displayed waveform use a singie sweep display Remote Input Signals The signal source requirements to operate the remote input functions on the rear panel can be either active pulse generator logic circuit etc or passive switch or relay Re fer to Table 1 4 in the General Information section for spe cific parameters on each input l Remote Reset Input An external single sweep reset signal can be applied to time base units installed in the hori zontal plug in compartments through the rear panel RE MOTE RESET INPUT connector This remote reset function is a duplication of the manuaily operated singie sweep reset function pushbutton located on the front panel of the 7B Series time base units Remote Erase Input The storage screen can be erased by applying a signal to the REMOTE ERASE INPUT How ever if the SAVE mode is being used the stored display cannot be erased by either the front panel erase button or the rea
5. 14 CONTROLS AND CONNECTORS 2 1 SAVE WITH NORMAL FRONT PANEL COLOR CODING 2 1 READOUT PA T ba A 2 14 OPERATOR S CHECKOUT SAVE WITH PULSED PROCEDURE a craw rhe 2 1 BEADOUT SE naaa 2 14 TEST EQUIPMENT REQUIRED 2 1 REDUCED SCAN MODE 2 14 PRELIMINARY SET UP 2 6 STORAGE DISPLAY oun 214 E DISPLAY FOCUS en 27 BISTABLE STORAGE 2 14 TRACE ALIGNMENT 2 7 VARIABLE PERSISTENCE GRATICULE ILLUMINATION 2 7 STORAGE 2 14 CONTROL ILLUMINATION 2 7 FAST STORAGE oaio 245 VERTICAL DEFLECTION SYSTEM 2 7 ERAGE APA 2 15 HORIZONTAL DEFLECTION SAVE MODE xis hbri e ie 2 15 SYSTEM sessi eo Mec CR 2 7 CARE OF STORAGE SCREEN 2 16 c 7934 Operators Page Section 2 OPERATING INSTRUCTIONS cont VERTICAL AND HORIZONTAL MODE COMBINATIONS 2 16 VERTICAL MODES 2 16 LEFT OR RIGHT osos xr s 2 16 ALTERNATE MODE 2 16 CHOPPED MODE 552 te votes 2 17 ALGEBRAIC ADDITION 2 17 HORIZONTAL MODES 2 18 A ORB Eee ANAPORA NG AN 2 18 ALTERNATE MODE 2 18 CHOPPED MODE mwaa naaa 2 18 HORIZONTAL SELECTION 2 18 VERTICAL TRACE SEPARATION 2 18 TRIGGER SOURCE ud naa owe on 2 18 CALIBRATOR OUTPUT 2 19 NEE 2 19 CURRENT Sada e RYE ADR Ca 2 19 REPETITION RATE ivre 2 19 WAVE SHAPE laauanaaasaa 2 19 SIGNAL OUTPUTS 2 19 SAWTOOTH OLT 2 19 GATE OUT wots cei s ee
6. 20 milliseconds division or whenever dual trace single shot phenomena are to be dis played At faster sweep rates the chopped switching be comes apparent and may interfere with the display When the A or B TRIGGER SOURCE switches are set to VERT MODE internal trigger signals from the vertical plug ins are algebraically added and the time base units are trig gered from the resultant signal In the LEFT VERT or RIGHT VERT trigger source positions the trigger signal to the time base units is a sample of the internal trigger signal from the selected vertical unit only This allows two time related signals to be displayed showing true time relationship If the signals are not time related the display from the channel that is not providing the trigger signal will appear unstable Operating Instructions 7934 Operator s The CHOP mode can be used to compare two single shot transient or random signals that occur within the time interval determined by the time base unit ten times selected sweep rate To provide correct trigaering the displayed sig nal which provides the trigger signal must precede the sec ond display in time Since the signals show true time relationship time difference measurements can be made from the display Algebraic Addition The ADD position of the VERTICAL MODE switch can be used to display the sum or difference of two signals for common mode rejection to remove an undesired signal or for dc offset appl
7. 6 of the instruction Manuai If there is damage or deficiency contact your local Tektronix Fieid Office or representative 1 1 General Information 7934 Operators Operating Power Information This instrument can be operated from either a 115 voit or 230 volt nominal supply source 48 to 440 hertz CAUTION To prevent damage to the instrument always check the setting of the LINE VOLTAGE SELECTOR switch located on the rear panel of the instrument before connecting the instrument to the supply circuit WARNING AC POWER SOURCE AND CONNECTION This in strument operates from a single phase power source It has a three wire power cord and two pole three terminal grounding type plug The voltage to ground earth from either pole of the power source must not exceed the maximum rated operating voltage 250 volts GROUNDING This instrument is safety class equip ment IEC designation All accessible conductive parts are directly connected through the grounding conductor of the power cord to the grounding contact of the power plug The power input plug must only be inserted in a mat ing receptacle with a grounding contact Do not defeat the grounding connection Any interruption of the grounding connection can create an electric shock hazard For electric shock protection the grounding connec tion must be made before making connection to the instrument s input or output terminals Power Cord information A
8. BS 1363 240V 6 13A Sn NEC 83 Ae Australian 240 V SAS C112 A3 240V 6 10A 1 TBD ANSI C73 20 Er pu P da 240 V NEMA 6 15 P A4 SEC 83 Switzerland 220 V SEV AS 220V 6 10A ANSI American National Standards Institute NEMA National Electrical Manufacturer s Association JEC international Electrotechnical Commission ACEE international Commission on Rules for the Approval Electrical Equipment 2 Enclose the instrument with polyethylene sheeting or equivalent to protect the finish of the instrument 3 Cushion the instrument on all sides by tightly packing dunnage or urethane foam between the carton and the in strument allowing three inches on each side 4 Seal the carton with shipping tape or with an industrial stapler 5 Mark the address of the Tektronix Service Center and your return address on the carton in one or more prominent locations 5BS British Standards institution 9AS Standards Association of Australia 7TSEV Schweizevischer Elektrotechischer Verein Table 1 3 SHIPPING CARTON TEST STRENGTH Gross Weight pounds Carton Test Strength pounds 0 10 10 30 30 120 120 140 140 160 200 275 375 500 600 1 3 General Information 7934 Operators SPECIFICATION The electrical characteristics listed in Table 1 4 apply at ambient temperatures between 0 and 50 C unless oth erwise stated when the following conditions are met 1 The instrument was adjusted at a
9. Full Scan Only High Voltage Overall Accelerating Voltage Geometry Beamfinder Stored Writing Speed Full Scan Center 6 x 8 Divisions FAST VAR PERSIST FAST BISTABLE VAR PERSIST BISTABLE Reduced Scan Center 8 x 10 Divisions FAST VAR PERSIST FAST BISTABLE VAR PERSIST BISTABLE Stored Save Time SAVE Mode BISTABLE and FAST BISTABLE Stored View Time VAR PERSIST and FAST VAR PERSIST General information 7934 Operators Table 1 4 cont Performance Requirement DISPLAY Internal illuminated with variable edge lighting 8 x 10 divisions 0 9 cm division 8 x 10 divisions 0 45 cm division centered on faceplate P31 10 lines division Approximately 10 kV approximately 12 kV in Reduced Scan Within 0 1 division of vertical and horizontal graticule lines Actuating BEAMFINDER limits display to within graticule area STORAGE 300 divisions microsecond 270 cm s 50 divisions microsecond 45 cm us 2 divisions microsecond 1 8 cm us 0 03 division microsecond 0 027 cm us 8 800 divisions microsecond 4 000 cm us 776 divisions microsecond 350 cm xs 12 divisions microsecond 5 4 cm us 0 2 division microsecond 0 09 cm us At least 30 minutes SAVE INTENSITY at minimum 30 seconds or more at maximum persistence 1 9 General information 7934 Operators Characteristic Auto Erase View Time Minimum Maximum Multi Trace Delay Time Minimum Maximum CONTROL ILLUMI
10. P6056 300 1 2 oe Rae 2 10976 7A22 None or 1 within 350 within Any 0 9 4 140 2 5 0 7 300 1 2 7A42 None 3 P6320 300 NA ch NI Ki T P P6131 EXT CAL 0 to 50 C Plug in gain set at a temperature within 10 C of operating temperature using an external calibrator with accuracy within 0 25 INT CAL 0 to 50 C Plug in gain set at a temperature within 10 C of operating temperature using the 7934 calibrator output signal 1 16 General information 7934 Operators Tabie 1 9 7934 OSCILLOSCOPE HORIZONTAL SYSTEM SPECIFICATION Time Base Performance Feature Maximum Calibrated Triggered Frequency Unit Sweep Rate Range 7B10 Delayed Sweep DC to 700 MHz 7880 DC to 400 MHz 7B85 Delaying Sweep DC to 400 MHz 7B87 Time Base with pre trigger acquire clock 1 ns div DC to 400 MHz when used with 7854 only 7B92A Display Switching 0 5 ns div DC to 500 MHz 1 17 General Information 7934 Operators lug in Unit Table 1 10 SPECIAL PURPOSE PLUG IN UNITS Performance Feature P 7CTIN 7D01 7D01F 7D02 7D02F 7D10 7D11 7D12 7D13A 7D14 7D15 7D20 7K11 7L5 71 12 7L13 7L14 7 18 7M11 7M13 7511 7512 7514 7T11A Low Power Semiconductor Curve Tracer Logic Analyzer Logic Analyzer Digital Events Delay Digital Delay A D Converter plug in modules provide flexible measurement capability Digital Multimeter Se Temperature voltage current and resistance measurement
11. V and 40 mV and notice that the displayed signal changes accordingly CALIBRATOR output must be termi nated into more than a 100 kilohm load for stated output When the CALIBRATOR output is terminated into 50 ohms the output is one tenth of the stated output Disconnect the CALIBRATOR signal Operating Instructions 7934 Operator s Z Axis Input 43 If an external signal is available two volts peak to peak minimum the function of the Z AXIS INPUT can be demonstrated Connect the external signal to both the input connector of the displayed amplifier unit and the rear panel Z AXIS INPUT connector Set the sweep rate of the dis played time base unit to display about five cycles of the sig nal Set the amplitude of the signal generator until intensity modulation is visible on the display change the amplifier unit deflection factor as necessary to produce an on screen display The positive peaks of the waveform should be blanked out and the negative peaks intensified Notice that the setting of the intensity controls determines the amount of intensity modulation that is visible Disconnect the cables Storage Operation 44 Connect the CALIBRATOR output to the input con nector of the left amplifier unit press the 4 V button and set the vertical deflection factor for a two division display Set the time base unit triggering mode to single sweep and set the sweep rate for 0 5 millisecond division 45 Press the BISTABLE button a
12. filter reduces the apparent light output from the ert Operating Instructions 7934 Operator s The beam current is limited during X Y mode operation or when either or both time base units being displayed are set for a slow sweep rate This reduces the danger of damaging the crt with a stationary or slowly moving spot Display Focus This instrument contains an automatic focusing circuit which maintains optimum focus for all intensity levels after a correct setting of the FOCUS control is established The easiest way to obtain the correct setting of the FOCUS con trol is to set the READOUT intensity control so that the readout portion of the display is clearly visible Then adjust the FOCUS control for best definition of the readout display Astigmatism and Focus Adjustments If a weil defined display cannot be obtained with the FOCUS control set the ASTIG adjustment as follows NOTE To check for proper setting of the ASTIG adjustment slowly turn the FOCUS control through the optimum setting If the ASTIG adjustment is correctly set the vertical and horizontal portions of the display will come nto focus at the same position of the FOCUS control This setting of the ASTIG adjustment should be correct for any display 1 install an amplifier unit in the LEFT VERT compart ment and a time base unit in the A HORIZ compartment 2 Set the VERTICAL MODE switch to LEFT and the HORIZONTAL MODE switch to A 3 Connect the outp
13. i a 4 H AEMOTE JAVE f EK NPL D i REMOTE STORAG f ad a INPUT p A De i 1 A5GY MAX bing H CAUTION ELECTRIC SHOCK HAZARD THIS INSTRUMENT MUST ag GROUNDED 2G NOT REMOVE COVERS REFS SERVICING TO QUALIFIED SEAVICE PERSONNEL 3 PICONET POWER INPUT BEFORE REPLACING WITH SAME TYPE A FAST 280 VOLT FUSE CONTAOL ILLUMINATION e UAE VOLTAGE SELEZYOR 3 JOR CONTINUED FAE HAZARD PROTECTION REPLACE i SINGLE SWEEP RESET ttSv max i LTE ELECTSCA amp ELECTRONIC MEASURING Ka TESTING EQUIPMENT GRATICULE READOUT sevmax SINGLE SHOT Z AXIS INPUT ISV MAX 20 l7 Fig 2 2a Rear panel controls and connectors QOOOCOOO eo Operating Instructions 7934 Operator s REAR PANEL CONTROLS AND CONNECTORS REMOTE ERASE INPUT Aliows external operation of the ERASE function REMOTE SAVE INPUT Allows external operation of the SAVE function REMOTE STORAGE GATE INPUT Allows external operation of the transfer function FAST BISTABLE and FAST VAR PERSIST only CONTROL ILLUMINATION Sets illumination level of the indicators and the lighted pushbutton switches on the 7934 front panel and the associated plug in units LINE VOLTAGE SELECTOR Sets instrument to 115 volt or 230 volt nominal line operation PROBE POWER two connectors Provides power to active probe system Z AXIS INPUT Input for external intensity modula
14. implosion shield pro vides protection to the operator from crt implosion An optional mesh filter is available from Tektronix in cluded with Option 03 This filter provides shielding against radiated electromagnetic interference from the face of the crt it also serves as a light filter to make the trace more visible under high ambient light conditions The mesh filter fits in place of the plastic tinted filter Order the mesh filter Tektronix Part 378 0603 00 Control Illumination The rear panel CONTROL ILLUMINATION switch sets the illumination level of the A and B INTENSITY indicators the A and 8 TRIGGER SOURCE switches and the lighted pushbutton switches on the plug in units The positions available are OFF MEDIUM and HIGH The CONTROL IL LUMINATION switch does not affect the function indicator lights on plug in units such as triggered or single sweep ready lights intensity Controls The A INTENSITY control determines the brightness of the display produced by the plug in unit installed in the A HORIZ compartment the B INTENSITY control determines the brightness of the display produced by the plug in unit installed in the B HORIZ compartment The READOUT in tensity control affects the brightness of only the readout portion of the crt display CAUTION Crt damage can occur under high intensity conditions Avoid any condition where an exiremely bright sharply focused dot exists on the crt Also remember that the light
15. information on specific plug in units used with the 7934 refer to the manual for that unit wARNING To avoid electric shock hazard see installation in the General Information section of this manual before op erating this instrument PLUG IN UNITS The 7934 accepts up to four Tektronix 7000 Series plug in units This feature allows selection of bandwidth sensitiv ity display mode etc and provides for future expansion of the system The overall capabilities of the system are mainly deter mined by the characteristics of the selected plug ins Some typical combinations are given under Applications in this section For information on other plug in units refer to the current Tektronix Products Catalog installation of Plug In Units CAUTION To prevent instrument damage plug in units should not be installed or removed without first turning the instrument power off To install a plug in unit into a compartment align the slots in the top and bottom of the plug in unit with the asso ciated guide rails in the plug in compartment Insert the plug in unit into the compartment until it locks into place To remove a plug in unit pull outward on the release latch to disengage the plug in To meet the EMC electromagnetic compatibility specifications cover all unused plug in compartments with an EMC shielded blank plug in panel Tektronix Part 016 0155 00 The gain of the 7934 vertical and horizontal systems has been
16. power cord with the appropriate plug configuration is supplied with the 7934 If you need to change the power plug refer to Table 1 1 and Table 1 2 for power cord and plug identification information Table 1 1 POWER CORD CONDUCTOR IDENTIFICATION Conductor Color Alternate Color Ungrounded Line Black Grounded Neutral White Grounded Earthing Green Yellow Green Yellow Operating Voltage The LINE VOLTAGE SELECTOR switch located on the rear panel allows selection of 115 volt or 230 volt nominal line voltage operation To convert from 115 volt to 230 voit operation change the power cord and plug to match the power source receptacle Then use a small screwdriver to move the LINE VOLTAGE SELECTOR switch to the desired range Operating Temperature The 7934 can be operated where the ambient air tem perature is between 0 and 4 50 C This instrument can be stored in ambient temperatures from 55 to 75 C After storage at temperatures outside the operating limits allow the chassis temperature to reach a safe operating limit be fore applying power The 7934 is cooled by air drawn in through holes in the top side and bottom panels and blown out through the fan exhaust To ensure proper cooling of the instrument main tain the clearance provided by the feet on the bottom and allow at least two inches clearance more if possible at the top sides and rear of the instrument Operating Position A bail type stand mo
17. therefore does not produce a sweep the other unit cannot produce a Sweep either This means that one time base unit cannot begin its sweep until the previous unit has completed its entire display This can be avoided if the time base units are set for auto mode triggering sweep free runs if not correctly triggered See Trigger Source for operation of the A and B TRIGGER SOURCE switches Also see Vertical Trace Separation for information on positioning the B HORIZ dis play when in the ALT dual sweep mode Chopped Mode When the CHOP button of the HORI ZONTAL MODE switch is pressed the display is electroni cally switched between the two time base units at about a 200 kilohertz rate In general the CHOP horizontal mode provides the best display when either of the time base units is set to a sweep rate slower than about 20 milliseconds division it also provides the best display when the two time base units are set to widely differing sweep rates in the CHOP horizontal mode equal time segments are displayed from each of the time base units This pro vides a display which does not change greatly in intensity as the sweep rate of either time base unit is reduced in con trast to ALT horizontal mode operation where the slowest trace tends to be the brightest The A and B INTENSITY controls allow individual adjust ment of the intensity of the traces produced by the time 2 18 base units in the A HORIZ and B HORIZ compartments Trigg
18. time base unit completes each sweep however there is no readout display during a storage erase cycle FAST BISTABLE in the FAST BISTABLE storage mode the readout display runs continuously as in the normal mode however the Readout System turns off at the begin ning of each erase cycle or when the single sweep time base mode is reset and remains off until the end of the storage transfer cycle In addition the Readout System is held off whenever the MULTI TRACE DELAY control is in operation out of its detent position and the displayed time base unit is in a repetitive sweep mode FAST VAR PERSIST In the FAST VAR PERSIST stor age mode one complete frame of readout is displayed after the completion of the storage transfer cycle However there is no readout during the storage erase cycle and there is no readout when the MULTI TRACE DELAY control is out of the detent position and the displayed time base unit is in a repetitive sweep mode Readout With Save Storage Mode When the SAVE storage mode is used operation of the Readout System changes from that previously described Refer to the SAVE mode discussion in this manual for information on SAVE storage mode operation 2 14 Save With Normal Readout With the READOUT control set in the variable area and any of the storage modes se lected the Readout System turns off approximately one second after the storage system enters the SAVE mode Save With Pulsed Readout
19. unit in one of the vertical plug in com partments Normally the time base unit in the vertical com partment should be set at a slower sweep rate than the time base unit in the horizontal compartment the number of horizontal traces in the raster depends upon the ratio be tween the two sweep rates Information can be displayed on the raster using several different methods In the ADD position of the VERTICAL MODE switch the signal from an amplifier unit can be alge braically added to the vertical waveform With this method the vertical signal amplitude on the crt should not exceed the distance between the horizontal lines of the raster An other method of displaying information on the raster is to use the Z AXIS INPUT to provide intensity modulation for the display This type of raster display could be used to provide a television type display Complete information on operation using the Z axis feature is given under Intensity Modulation To provide a stable raster display both time base units must be correctly triggered Internal triggering is not pro vided for the time base units when they are in the vertical compartments external triggering must be used Also blanking is not provided from the time base units when they are installed in a vertical compartment 2 23 Section 3 7934 Operators INSTRUMENT OPTIONS Your instrument may be equipped with one or more in strument options A brief description of each avai
20. 92 7B92A 75 No display No vertical signal connection Leading edge of triggering 7934 delay line length waveform cannot be viewed 7934 Horizontal Mode alternate with both horizontal time base units set for single sweep operation Only one time base unit will reset SAVE AUTO ERASE PULSED readout and fast storage modes do not operate normally 7934 alternate sweep switching logic locks out one time base unit these time base units do not reset when locked out Time base unit will not automatically reset 7934 fast storage modes with time base unit set for single sweep operation 7934 bistable or variable persistence with horizontal ALT or CHOP mode and A HORIZ time base unit in repetitive sweep mode delaying B HORIZ time base unit in single sweep mode Time base unit is locked out during erase intensified zone s may appear Delay in 7934 storage logic at incorrect position between end of sweep lockout and single sweep reset 7B85 sweeps once but needs to sweep twice for generation of holdoff pulse SAVE AUTO ERASE PULSED readout and fast storage modes do not operate normally SAVE AUTO ERASE PULSED readout and fast storage modes do not operate normally 7B85 set for single sweep operation with delta time function operational Time base unit set for alternate and single sweep modes Time base unit sweeps only once when re
21. ATOR Manual Section Location of Information Section 1 General Information Specification Table 1 4 contains the electrical characteristics for Option 02 Section 6 Horizontal System Checks and E3 Check Adjust X Y Compensation Adjustments Section 7 Replaceable Electrical Parts Replaceable Replaceable parts unique to Option 02 are Electrical Parts footnoted Option 02 only Section 8 Diagrams and Circuit Board lilustrations Horizontal Interface Diagram 8 Diagram 8 shows circuitry unique to Option 02 Section 9 Replaceabie Mechanical Parts Instrument Options pull out page Provides a mechanical parts list and an expioded view drawing unique to Option 02 Section 1 General Information Section 02 Operating Instructions Specification Table 1 4 contains the electrical characteristics for Option 03 Detailed Operating Information Light Filter includes basic description installation of Plug In Units Refers to EMC shielded biank plug in panel Section 7 Replaceable Electrical Parts Replaceable Electrical Parts Replaceable parts unique to Option 03 contain the footnote Option 03 only Section 9 Replaceable Mechanical Parts instrument Options pull out page Provides a mechanical parts list and an exploded view drawing unique to Option 03
22. B 2 Tested to MIL STD 810C Method 507 1 Procedure IV modified as specified in Mil T 28800C paragraph 4 5 5 1 12 except 90 95 relative humidity steps 5 and 6 operating tests at 50 C step 5 second cycle 0 to 15 kV with no performance degradation 0 to 20 kV with no instrument damage General information 7934 Operators Table 1 6 PHYSICAL Characteristic information Ventilation Safe operating temperature maintained by dc fan Warm up Time 30 minutes for rated accuracy Finish Anodized front and rear panel with blue vinyl painted aluminum cabinet Overall Dimensions Measured at maximum points see Fig 1 1 for dimensional drawing Height 34 5 cm 13 6 inches Width 30 5 cm 12 0 inches Length 62 25 cm 24 5 inches Net Weight Instrument Only 17 2 kg 38 0 pounds ni Papano pp AA AA el gt NOTE DIMENSIONS ARE GIVEN WITH TOP FIGURE IN INCHES AND BOTTOM FIGURE IN CENTIMETERS Figure 1 1 7934 dimensional drawing General Information 7934 Operators SYSTEM ELECTRICAL SPECIFICATION The Tektronix 7934 Oscilloscope system provides ex ceptional flexibility in operation with a wide choice of gen eral and special purpose plug in units The type number of a particular plug in unit identifies its usage as follows The first digit 7 denotes that the unit is designed to operate in a 7000 series oscilloscope system The second letter describes the purpose of the plug in unit as follows A
23. From dc to at least 1 MHz From dc to at least 1 MHz TRIGGER SYSTEM Selected by front panel TRIGGER SOURCE switches From vertical plug in unit selected by VERTICAL MODE switch CHOP mode signals are added algebraically From left vertical plug in unit only From right vertical plug in unit only 1 5 General information 7934 Operators Characteristic Waveshape Polarity Source impedance Output Voltage into 100 Kilohms or Greater into 50 Ohms Output Current Amplitude Accuracy P P Voltage Repetition Rate Duty Factor Rise Time and Fall Time Sawtooth Output Source A Sweep B Sweep Polarity Output Voltage Rate of Rise Into 50 ohms Into 1 Megohm Output Resistance 1 6 Table 1 4 cont Performance Requirement CALIBRATOR Square wave Positive going with baseline near zero volts Approximately 450 ohms Selected by front panel CALIBRATOR switch 40 mV 0 4 V 4 V 4 mV 40 mV 0 4 V 40 mA available through CALIBRATOR output with optional BNC to Current Loop adapter CALIBRATOR switch must be set to 4 V for calibrated current output Within 196 1 kHz within 0 2596 49 8 to 50 296 250 nanoseconds or less into 100 pF or less SIGNAL OUTPUTS Selected by internal Sweep Selector jumper A HORIZ time base unit or B HORIZ time base unit Derived from A HORIZ time base sweep Derived from B HORIZ time base sweep Positive going with baseline at 0 V within 1 V into 1 Meg
24. MODE notice that this button is illuminated 33 The B TRIGGER SOURCE switch operates in a manner similar to the A TRIGGEH SOURCE switch when the B time base unit is selected to provide the display Set the B TRIGGER SOURCE switch to VERT MODE and the VERTICAL MODE switch to ALT 34 Set the HORIZONTAL MODE switch to ALT or CHOP Notice that this is the same display obtained in step 29 slaved alternate operation Readout 35 Turn the READOUT control clockwise until an alpha numeric display is visible within the top or bottom division of the screen Change the deflection factor of the amplifier unit that is selected for display notice that the readout display changes as the deflection factor is changed Likewise change the sweep rate of the time base unit which is se lected for display notice that the readout display for the time base unit changes as the sweep rate is changed 36 Set the time base unit for X10 magnification Notice that the readout display changes to indicate the correct magnified sweep rate If a readout coded 10X probe is avall able for use with the amplifier unit install it on the input connector of the right amplifier plug in unit Notice that the deflection factor indicated by the readout is increased by 10 times when the probe is added Return the time base unit to normal sweep operation and disconnect the probe 37 Sequentially select all of the VERTICAL MODE and HORIZONTAL MODE switch positions No
25. NATION PROBE POWER REMOTE RESET INPUT REMOTE STORAGE GATE INPUT REMOTE ERASE INPUT REMOTE SAVE INPUT Voltage Range ac rms 115 V Nominal 230 V Nominai Line Frequency Maximum Power Consumption Maximum Current 90 V Line 180 V Line Line Fuse Table 1 4 cont Performance Requirement Less than 1 second Greater than 10 seconds Less than 1 second Greater than 4 seconds REAR PANEL CONNECTORS AND SWITCHES High medium and off three position switch located on rear panel of power supply Two connectors for compatible Tektronix probes Input to reset single sweep function of time base units installed in A and B HORIZ compartments compatible time base units only High to low transition resets sweep Allows remote operation of high speed transfer Low to high transition enables High Speed Target to receive information to be stored High to low transition initiates transfer from high speed target to storage target Allows remote erasure of stored display High to low transition initiates an erase cycle when in a storage mode Allows remote control of Save mode High state allows control from front panel Low state holds storage circuitry in Save mode when in storage mode POWER SOURCE Selected by rear panel LINE VOLTAGE SELECTOR switch From 90 V to 132 V From 180 V to 250 V From 48 to 440 Hz 230 Watts 3 5 amps at 60 Hz 1 8 amps at 60 Hz 4 amp fast blow Characteristic General Infor
26. ND CONNECTORS cx pake pa NP ers 2 4 DEFINITION OF GRATICULE MEASURE MENT LUNES o uidens ennt Saw aiv rog 2 11 LOCATION OF READOUT ON THE CRT IDENTIFYING THE ORIGINATING PLUG IN AND CHANNEL amd knb NG 2 13 LOCATION OF READOUT ON THE CRT WHEN REDUCED SCAN IS SELECTED 2 13 LIST OF TABLES Tabie No 1 1 Page POWER CORD CONDUCTOR IDENTIFICA BONG uincere rod es E C ad CH ers 1 2 POWER CORD AND PLUG IDENTIFICATION NEEN 1 3 SHIPPING CARTON TEST STRENGTH 1 3 ELECTRICAL CHARACTERISTICS 1 4 ENVIRONMENTAL 1 11 PR SCAN a tn SD de we ban NA 1 12 PLUG IN INCOMPATIBILITIES 1 14 7934 OSCILLOSCOPE VERTICAL SYSTEM SPECIFICATION ia 1e teat bere e 1 16 7934 OSCILLOSCOPE HORIZONTAL SYSTEM SPECIFICATION 1 17 SPECIAL PURPOSE PLUG IN UNITS 1 18 DISPLAY COMBINATIONS 2 16 OPTION INFORMATION LOCATOR 3 2 7934 Operators 7934 Operators OPERATORS SAFETY INFORMATION The following general safety information applies to all operators and service personnel Specific warnings will be found throughout the manual where they apply and should be followed in each instance WARNING statements identify conditions or practices which could result in personal injury or loss of life CAUTION statements identify conditions or practices which could result in damage to the equipment or other property The word DANGER on the equipment identifies areas of immediate hazard whic
27. OPERATORS Part No 070 5879 00 TE MANUAL Product Group No 42 7934 OSCILLOSCOPE WARNING The following service instructions are for use by quali fied personnel only To avoid personal injury do not perform any service other than that contained in op erating instructions unless you are qualified to do so Refer io Operators Safety Summary and Service Summary prior to performing any service Please Check for CHANGE INFORMATION at the Rear of This Manual First Printing MAY 1986 m Tektronix COMMIT TED TO EXCELLENCE Copyright 1986 Tektronix Inc All rights reserved Contents of this publication may not be reproduced in any form without the written permission of Tektronix Inc Products of Tektronix Inc and its subsidiaries are covered by U S and foreign patents and or pending patents TEKTRONIX TEK SCOPE MOBILE and ien are registered trademarks of Tektronix Inc Printed in U S A Specification and price change privileges are reserved Tektronix Inc P O Box 500 Beaverton Oregon 97077 Serial Number 7934 Operators BLE OF CONTENTS Page Page LIST OF ILLUSTRATIONS ii Section 2 OPERATING INSTRUCTIONS cont LIST OR TABLES igen lads cut ied rr aya i OPERATORS SAFETY SUMMARY iv TRIGGERING 2 8 7934 FEATURES osx cedi ud ue e Are RE oen vi READOUT da vor Se 2 8 BEAMFINDER 005 2 9 Section 1 GENERAL INFORMATION CALIBRATOR Leer Za denger 2 9 INTRODUCTION esee 1 1 ZA nG ein
28. SAVE mode simplifies pho tography by allowing the operator to control the intensity of the stored display The SAVE mode can be selected with or without a stored display present If it is selected after an erase cycle and before a sweep has occurred no stored display the display waits in the STORE mode until a sweep occurs at which time the display automatically enters the SAVE mode This is referred to as the Auto Save mode 2 15 Operating Instructions 7934 Operators Care of Storage Screen The following precautions will prolong the useful storage life of the crt in this instrument 1 Use minimum beam intensity to produce a clear well defined display 2 Use minimum SAVE INTENSITY when storing images for extended periods of time 3 Avoid repeated use of the same area of the screen If a particular display is to be stored repeatedly change the vertical position occasionally to use other portions of the display area Vertical and Horizontal Mode Combinations There are 20 possible combinations of VERTICAL MODE and HORIZONTAL MODE switch settings The total possi ble number of display combinations is further multiplied by the variety of plug in units available for use with this instru ment the interchangeability of plug ins e g either an ampli fier or a time base unit can be installed in any compartment and by the capabilities of the plug in units which are used in the instrument e g a dual trace amplif
29. T Display alternates between left and right vertical plug in units ADD Display is algebraic sum of left and right vertical plug in units CHOP Display chops between left and right vertical plug in units RIGHT Chopped Mode Repetition Rate Vertical Trace Separation Signal from right vertical plug in unit displayed 1 MHz within 20 Positions B trace at least four divisions above and below A trace when 7934 operates in dual sweep mode 1 4 Characteristic Deflection Factor Difference Between Horizontal Compartments Fastest Calibrated Sweep Rate Horizontal Dispiay Mode A ALT CHOP B Chopped Mode Repetition Rate Phase Shift Between Vertical and Horizontal Deflection Systems With Option 02 B HORIZ Compartment Only Bandwidth 7934 Horizontal System Only with 10 Division Reference With Option 02 B HORIZ Compartment Only A and B TRIGGER SOURCE VERT MODE LEFT VERT RIGHT VERT General Information 7934 Operators Table 1 4 cont Performance Requirement HORIZONTAL SYSTEM Compatible with ali 7000 series plug in units 196 or less 0 5 nanosecond division Selected by front panel HORIZONTAL MODE switch A horizontal plug in unit displayed Display alternates between A and B horizontal plug in units Display chops between A and B horizontal plug in units B horizontal plug in unit displayed 200 kHz within 20 2 or jess from dc to at least 35 kHz 2 or less from dc to 1 MHz
30. With the READOUT control set to PULSED and the storage mode switch set to BISTABLE or FAST BISTABLE the readout is displayed for approximately one second after the storage system enters the SAVE mode then it turns off With the READOUT con trol set to PULSED and the storage mode switch set to VAR PERSIST one complete frame of readout is displayed at the end of the displayed sweep With the READOUT con troi set to PULSED and the storage mode switch set to FAST VAR PERSIST one frame of readout is displayed at the end of the storage transfer cycle or whenever the stor age system is set to the SAVE mode and the MULTI TRACE DELAY control is out of its detent position Reduced Scan Mode The reduced scan mode increases the stored writing speed The calibrated graticule division is reduced to 0 45 centimeters in the reduced scan mode Calibrated measure ments are confined to the inner half size 8 x 10 graticule area The operation of the instrument controls do not change from their operation in the full scan mode Storage Display The 7934 Storage Oscilloscope has four selectable stor age modes Listed in order of increasing writing speed they are BISTABLE VAR PERSIST FAST BISTABLE and FAST VAR PERSIST In each mode the viewed image is stored on the storage target located in the front of the cri Bistable Storage In the BISTABLE made the luminance of any point on the storage target takes on one of two dis crete levels either writ
31. ace when the identify button is pressed see the plug in unit instruction manual for details Readout intensity The READOUT control determines the intensity of only the readout portion of the display independently of the Operating Instructions 7934 Operator s LEFT VERT CHANNEL 1 RIGHT VERT CHANNEL 1 A HORIZ CHANNEL 1 8 HORIZ CHANNEL 1 A HORIZ CHANNEL 2 RIGHT VERT CHANNEL 2 LEFT VERT CHANNEL 2 B HORIZ CHANNEL 2 1987 5 Figure 2 5 Location of readout on the crt when reduced scan is selected traces The Readout System is inoperative when the READ OUT control is in the fully counterclockwise OFF position This may be desirable when the top and bottom divisions of the graticule are to be used for waveform display or when the trace interruptions necessary to display characters inter fere with the waveform display Readout Modes The READOUT intensity control determines the operat ing mode of the Readout System With the READOUT in tensity contro set in the variable area the Readout System operates continuously interrupting the crt display at ran dom for about 20 microseconds in order to write each character on the crt In the PULSED position the Readout System operates in a triggered mode one complete frame up to eight words of readout is displayed after the dis played time base unit completes each sweep of the crt Brightness of the readout display when ope
32. base units throughout their ranges Observe that two traces are displayed on the screen at all sweep rates Also notice that when both time base units are set to a slow sweep rate 50 milliseconds division or slower both traces are visible on the screen at the same time Re turn the sweep rate switches of both time base units to 0 5 millisecond division 27 Set the CALIBRATOR switch to 0 4 V Set the VER TICAL MODE switch to CHOP Four traces should be dis played on the screen If not adjust the position controls of the amplifier units and the VERT TRACE SEPARATION B control to position the four traces into view Set the position controls of the plug in units to identify which trace is pro duced from each plug in unit if amplifier units have the iden tify feature it can be used to identify the traces Set the A time base unit for a sweep rate of 1 millisecond division Notice that the ieft amplifier unit is displayed at the sweep rate of both the A and B time base units and that the right amplifier unit is also displayed at the sweep rate of both time base units 28 Set the HORIZONTAL MODE switch to ALT Ob serve that the display is very similar to that obtained in the previous step The main difference in this display is that the traces are now displayed alternately noticeable only at slow Sweep rates 29 Set the VERTICAL MODE switch to ALT Set the CALIBRATOR switch to 4 V Notice that the trace produced by the left ampli
33. can be set to display the signal from an amplifier unit installed in one of the horizontal compart ments The HORIZONTAL MODE switch can then select the other horizontal compartment with a time base unit in stalled allowing the storage circuitry and crt unblanking to be controlled by the time base unit while the horizontal de flection is provided by the amplifier unit Vertical Trace Separation When one of the dual sweep horizontal modes is se lected the VERT TRACE SEPARATION B control allows the trace produced by the B HORIZ sweep to be positioned above or below the trace produced by the A HORIZ sweep To use this control first position the trace produced by the A HORIZ plug in unit with the vertical position control Then adjust the VERT TRACE SEPARATION B control to move the trace produced by the B HORIZ plug in unit away from the A HORIZ display If both waveforms are larger than four divisions in amplitude the displays can only be positioned so they do not directly overlap since each waveform cannot be positioned to a unique area of the crt Trigger Source The A and B TRIGGER SOURCE switches select the internal trigger signais for the A HORIZ and B HORIZ time base units For most applications these switches can be left in the VERT MODE position This position is the most con venient since the internal trigger signal is automatically switched as the VERTICAL MODE switch is changed or as the display is electronically swit
34. ched between the LEFT VERT and RIGHT VERT plug ins in the ALT position of the VERTICAL MODE switch It also provides a usable trigger signal in the ADD position of the VERTICAL MODE switch since the internal trigger signal in these modes is the alge braic sum of the signals applied to the vertical plug in units in the CHOP position the left vertical plug in is the trigger source Therefore the VERT MODE position ensures that the time base units receive a trigger signal regardless of the VERTICAL MODE switch setting without the need to change the trigger source selection If correct triggering for the desired display is not obtained in the VERT MODE position the trigger source for either the A HORIZ or B HORIZ time base unit can be changed to obtain the trigger signal from either the LEFT VERT or RIGHT VERT plug in The internal trigger signal is obtained from the selected vertical compartment whether the plug in in that compartment is selected for display on the crt or not Af the internal trigger signal is obtained from one of the verti cal units but the other vertical unit is selected for display the internal trigger signal must be time related to the displayed signal in order to obtain a triggered stable display Calibrator Output The CALIBRATOR provides a convenient signal for checking basic vertical gain and sweep timing The calibra tor signal is aiso very useful for adjusting probe compensa tion as described in probe inst
35. control fully clock wise then slowly increase the A INTENSITY control clock wise until the display stores Notice that each sweep is stored without erasing the previously stored sweep This is easily observed if the vertical position control is varied be tween sweeps 2 10 58 Press the ERASE button and notice that the display is erased 59 Set the time base unit for single sweep and press the ERASE button Notice that only one sweep is stored trigger time base unit if necessary 60 Change the setting of the vertical position control and initiate another sweep by pressing the reset button on the time base unit Notice that the new sweep is stored along with the one stored in the previous step 61 Alternately press the ERASE button and reduce the A INTENSITY control to the point where the display just fails to store 62 Alternately increase the STORAGE LEVEL clock wise and press the ERASE button Notice that as the STORAGE LEVEL is increased the display begins to store 63 The FAST VAR PERSIST mode operates as out lined for the VAR PERSIST mode except that the sweep and transfer functions are operative as described for FAST BISTABLE operation 64 Press the BISTABLE button Set the time base unit for auto triggering 65 Set the A INTENSITY control to the one o clock po sition Turn the AUTO ERASE control out of the detent po sition and notice that the erase cycles occur automatically and with increasing fre
36. ction 1 General Information contains instrument description electrical specifications environmental charac teristics standard and recommended accessories installa tion and instructions for packaging for shipment Section 2 Operating Instructions contains informa tion relative to operating and checking the instrument operation Section 3 instrument Options contains a description UN of available options and gives the location of the associated information for those options Instruction Manual The Instruction Manual contains both operating and ser vicing information for the 7934 Storage Oscilloscope Sec tions 1 through 3 of the Instruction Manual contain the same information as Sections 1 through 3 of the Operator s Man ual the remaining sections of the Instruction Manual are as follows WARNING The additional sections of the Instruction Manual con ta n servicing instructions These servicing instruc tions are for use by qualified service personnel only To avoid electric shock or other personal injury do not perform any servicing other than that described in the Operating Instructions unless you are qualified Section 4 Theory of Operation contains basic and general circuit analysis to help in understanding the opera tion of the instrument and that may be useful for servicing o the instrument Section 5 Maintenance describes routine and correc tive maintenance procedures with detai
37. d time base operation The 7934 is set to the Erase After Sweep mode at the factory Both time base units and the readout system are inhib ited during the erase cycle Also during each erase cycle the displayed time base unit is reset if it is in single sweep mode The other time base will aiso be reset at this time if it Operating Instructions 7934 Operator s is also in single sweep mode in the BISTABLE and VAR PERSIST storage modes the erase cycle takes approxi mately 1 4 seconds The additional time is required for pre paring the fast target In ail storage modes the time base unit s is free to run immediately following an erase cycle However in FAST BISTABLE or FAST VAR PERSIST storage modes the time base unit s is locked out immediately after the first sweep occurs so that transfer can occur In the ALT or CHOP horizontal modes both time base units are allowed to run once before transfer occurs if the time base unit s is set for single sweep operation it remains locked out indefi nitely after transfer occurs The operator can initiate a cycle however called the multi trace cycle which causes another trace to be stored without erasing the initial display This is accomplished by pressing the single sweep reset button on the time base unit s or by grounding the REMOTE RESET INPUT on the 7934 rear panel When this is done the stor age system initiates a cycle lasting approximately 600 milli seconds which prepa
38. e one BNC male Type BNC T connector Tektronix Part 103 0300 00 6 Adapter Description Connectors BNC female to BNC female Type BNC female to BNC female adapter Tektronix part 103 0028 00 2 6 Preliminary Set Up 1 Set the front panel controls as follows A INTENSITY Counterclockwise FOCUS Midrange B INTENSITY Counterclockwise READOUT OFF GRAT ILLUM Counterclockwise REDUCED SCAN Button out STORE OFF Button in POWER Button out CALIBRATOR 4V VERTICAL MODE LEFT A TRIGGER SOURCE VERT MODE HORIZONTAL MODE A VERT TRACE SEPARATION B Midrange B TRIGGER SOURCE VERT MODE Horizontal Selector at rear Norm of A HORIZ compartment 2 Connect the 7934 to a power source that meets the voltage and frequency requirements H the available line voltage is outside the limits of the LINE VOLTAGE SELEC TOR switch setting on rear panel see Operating Power Information under Installation General Information Section 3 Instali Tektronix 7A Series amplifier units in the LEFT VERT and RIGHT VERT compartments Install Tektronix 7B Series time base units in the A HORIZ and B HORIZ compartments 4 Press the POWER switch to the on position button in 5 Set both time base units to 1 millisecond division and triggering to auto mode with ac coupling from the internal source 6 Rotate the A INTENSITY control until the trace is at a desirable viewing level near midrange Position the trace as necessary for a
39. e 2 19 VERTICAL SIGNAL 2 19 PROBE POWER ice repr p 2 20 DISPLAY PHOTOGRAPHY 2 20 INTENSITY MODULATION 2 20 REMOTE INPUT SIGNALS 2 20 REMOTE RESET INPUT 2 21 REMOTE ERASE INPUT 2 21 REMOTE SAVE INPUT 2 21 TABLE OF CONTENTS cont REMOTE STORAGE GATE INPUT 2 21 Page Section 2 OPERATING INSTRUCTIONS cont APPLICATIONS 0 0000005 2 21 VERTICAL AMPLIFIER PLUG IN UNITS S cesarean takes wasn 2 21 SINGLE TRACE 2 21 DUAL TRACE 2 21 THREE TRACE 2 21 FOUR TRACE esses 2 21 TIME BASE PLUG IN UNITS 2 21 SAMPLING DISPLAYS 2 22 SINGLE TRACE SAMPLING 2 22 DUAL TRACE SAMPLING 2 22 X Y SAMPLING 2 22 SPECIAL PURPOSE PLUG IN UNITS 2 22 DIGITAL COUNTERS AND MULTIMETER PLUG IN UNITS 2 22 READOUT ACCESS PLUG IN UNITE oes SER oor le 2 22 TRANSISTOR CURVE TRACER PLUG IN UNIT Ae gei NG 2 22 SPECTRUM ANALYZER PLUG IN UNITS MEA 2 23 AX OPERATION ous os eas ta wees 2 23 RASTER DISPLAYS 2 23 Section 3 INSTRUMENT OPTIONS OPTION G2 ous xc x dei S Rh 3 1 OPTION 03 cei seb Ka AA 3 1 CHANGE INFORMATION LIST OF ILLUSTRATIONS Fig No 2 2 2 3 2 4 2 5 Page FRONTISPIECE 7934 FEATURES vi 7934 DIMENSIONAL DRAWING 1 12 FRONT PANEL CONTROLS CONNEC TORS AND INDICATORS 2 2 REAR PANEL CONTROLS A
40. e ene i ae OPERATOR S MANUAL E See ii NECI Mu E des DETAILED OPERATING INFORMATION 2 11 TEE 1 1 Een En INITIAL INSPECTION 1 1 HORT PILA Eei esas oue n OPERATING PONER INFORMATION SES CONTROL ILLUMINATION 241 POWER CORD INFORMATION 1 2 NTEN SITE CONTROLS Set aasa E OPERATING VOLTAGE 1 2 DISPLAY PORTS ans eet dida SR OPERATING TEMPERATURE 12 AS HOGMATISM AND FOCUS OPERATING POSITION 1 2 ADJUSTMENT Saang me aches ale M LINGO E RIS M s BEAMFINDER 5 ccrte tente 2 12 SPECIFICATION esee 1 4 TRACE REID NN EN desc yaad Ga ele ELECTRICAL CHARACTERISTICS 1 4 READOUT eae nese Prio ele ENVIRONMENTAL 0 1 11 Mou ds TE a Ba e Se READOUT INTENSITY n u 2 13 SYSTEM ELECTRICAL SPECIFICATION 1 13 RE POON MODE duse esu tts SH PLUG IN INCOMPATIBILITIES 1 14 READBUPOPENATBN ere 7934 OSCILLOSCOPE VERTICAL STORAGE EI cs aaa is SYSTEM SPECIFICATION 1 16 NORMAL READOUT MODE Do ES 7934 OSCILLOSCOPE HORIZONTAL POTAS FE ANU NAR PERSON seis SYSTEM SPECIFICATION 147 Bio nA BIEN pant SPECIAL PURPOSE PLUG IN UNITS 1 18 Mad BERSO Laan ee STANDARD ACCESSORIES 1 19 PULI ANON MPG ae cla RECOMMENDED ACCESSORIES 1 19 DIS UBER toy atte oe VAR PERSIST aaoo 2 14 Section 2 OPERATING INSTRUCTIONS PAST ee ch FAST VAR PERSIST 2 14 PLUG IN UNITS Ceca re eee Le 2 1 READOUT WITH SAVE STORAGE INSTALLATION OF PLUG IN UNITS 2 1 MODE vd Ser LM SE 2
41. ering is not as critical in the CHOP horizontal mode as in ALT if one of the units is not triggered properly only the trace from the untriggered time base unit is missing from the display The other trace is presented in the normal manner See Trigger Source and Vertical Trace Separation for in formation on positioning the trace produced by the B HORIZ unit in relation to the trace from the A HORIZ unit Horizontal Selection The Horizontal Selector switch lo cated behind the metal shield at the rear of the A HORIZ compartment provides a means to override the HORIZON TAL MODE switch in selecting the horizontal compartment for deflection The Horizontal Selector switch has three po sitions Normal A and B In Normal the operation of the HORIZONTAL MODE switch is unchanged in A or B the plug in compartment selected by the Horizontal Selector switch provides the signal for horizontal deflection The plug in compartment selected by the HORIZONTAL MODE switch provides the other control signals such as unblanking storage control etc The Horizontal Selector switch is set to Normal at the factory The Horizontal Selector switch provides a method of storing X Y displays using the FAST BISTABLE or FAST VAR PERSIST storage modes These storage modes re quire control signals provided by a time base unit or an ex ternal input signal see Remote Storage Gate Input to develop a stored display For X Y storage the Horizontal Selector switch
42. es power for camera operation and receives single sweep reset signal 5 TRACE ROTATION Screwdriver adjustment to align trace s with graticule lines 6 ASTIG Screwdriver adjustment used with the FOCUS contro to obtain a well defined display 7 A INTENSITY indicator Hiuminates when A HORIZ plug in selected for display A INTENSITY Controls brightness of trace produced by the plug in installed in the A HORIZ compartment 3 FOCUS Optimizes crt trace definition B INTENSITY indicator illuminates when B HORIZ plug in selected for display D B INTENSITY Controis brightness of trace produced by the plug in installed in the B HORIZ compartment BEAMFINDER When pressed compresses and defocuses display within graticule area 13 REDUCED SCAN switch and indicator Calibrated area of crt is reduced to inner half size graticule and stored writing speed is increased when indicator is on 14 Storage Mode Switch not labeled Selects one of four Storage modes or the STORE OFF display mode 15 STORAGE LEVEL Varies writing speed of VAR PERSIST FAST BISTABLE and FAST VAR PERSIST storage modes SAVE control and indicator Retains stored display in a noneraseable mode with continuously variable intensity when indicator is on MULTI TRACE DELAY Controls time between successive sweeps when operating in FAST BISTABLE and FAST VAR PERSIST storage modes AUTO ERASE Controls viewtime in aut
43. fier unit is displayed at the sweep rate of the B time base unit and the trace produced by the right ampli fier unit is displayed at the A time base unit sweep rate This feature is called slaved alternate operation and is obtained 2 8 only when the VERTICAL MODE switch is in the ALT posi tion the HORIZONTAL MODE switch is in either the ALT or the CHOP position and the time base units are in the inde pendent mode Triggering 30 Set the VERTICAL MODE switch to LEFT and the HORIZONTAL MODE switch to A Center the display on the screen with the left amplifier unit position control Discon nect the input signal from the right amplifier unit input con nector Sequentially select all of the VERTICAL MODE switch positions Notice that a stable display is obtained for all positions of the VERTICAL MODE switch a straight line in RIGHT switch position 31 Set the A TRIGGER SOURCE switch to LEFT VERT Again sequentially select all of the VERTICAL MODE switch positions Notice that the display is again sta ble in all positions as in the previous step and that the LEFT VERT button is illuminated 32 Set the A TRIGGER SOURCE switch to RIGHT VERT Sequentially select all of the VERTICAL MODE switch positions and notice that a stable display cannot be obtained in any position this is because there is no input signal connected to the right vertical unit The RIGHT VERT button is illuminated Return the A TRIGGER SOURCE switch to VERT
44. h could result in personal injury or loss of life The following safety symbols may appear on the equipment AN CAUTION Refer to manual h DANGER High voltage Protective ground earth terminal Other warning symbols where they apply WARNING AG Power Source and Connection This instrument operates from a single phase power source It has a three wire power cord and a two pole three terminal grounding type plug The voltage to ground earth from either pole of the power source must not exceed the maximum rated operating voltage 250 volts Before making connection to the power source determine that the instrument is adjusted to match the voltage of the power source and has a suitable two pole three terminal grounding type connector Hefer any changes to qualified service personnel Grounding the Instrument This instrument is safety class equipment IEC designation All accessible conductive parts are directly connected through the grounding conductor of the power cord to the grounding contact of the power connector The power input plug must only be inserted in a mating receptacle with a grounding contact Do not defeat the grounding connection Any interruption of the grounding connection can create an electric shock hazard Refer to qualified service personnel for verification of adequate protective grounding system to which this instrument is to be connected For electric shock protection the grounding connectio
45. id screen display if viewed in the LEFT or RIGHT positions of the VERTICAL MODE Switch 4 For similar response from each channel use identical plug ins and set the plug in units for the same input coupling mode 2 17 Operating instructions 7934 Operator s Horizontal Modes A or B When either the A or B button of the HORIZON TAL MODE switch is pressed the signal is displayed at the sweep rate of the selected time base unit Set the applicable intensity control and trigger source switch for the desired display Alternate Mode The ALT position of the HORIZONTAL MODE switch provides crt sweeps derived alternately from the two time base units Although the ALT horizontal mode can be used at ali sweep rates the CHOP mode provides a more satisfactory display at sweep rates below about 20 milliseconds division At slower sweep rates the switching between the alternate mode traces becomes apparent and may interfere with correct analysis of the display NOTE This instrument will not operate in the ALT position of the HORIZONTAL MODE switch if either horizontal plug in compartment is left vacant The A and B INTENSITY controis allow individual adjust ment of the traces produced by the time base units in the A HORIZ and B HORIZ compartments Correct triggering of both time base units is essential in obtaining the correct dis play in the ALT horizontal mode If either of the time base units does not receive a correct trigger and
46. ier unit can be used in either of the two single channel modes in the dual trace mode or added algebraically mode a deiaying time base may be used either for a normal sweep or for delayed sweep Therefore it is difficult to list all of the display com binations which can occur during use of the 7934 and avail able plug in units Table 2 1 lists the combination of VERTICAL MODE and HORIZONTAL MODE switch posi tions available and the type of display obtained with each combination Vertical Modes Left or Right When the LEFT or RIGHT button of the VERTICAL MODE switch is pressed only the signal from the plug in unit in the selected compartment is displayed Alternate Mode The ALT position of the VERTICAL MODE switch produces a display which alternates between the LEFT VERT and RIGHT VERT compartments with each sweep of the crt Although the ALT mode can be used at all sweep rates the CHOP mode provides a more satisfactory Table 2 1 DISPLAY COMBINATIONS Horizontal Mode Vertical Mode LEFT AorB ALT or CHOP ALT Aor B ALT or CHOP section ADD Aor B ALT or CHOP Aor B ALT or CHOP Aor B ALT or CHOP CHOP RIGHT Comments One trace Vertical deflection from single unit horizontal deflection from single unit Two traces Vertical deflection from single unit horizontal deflection from both units Two traces Vertical deflection from both units horizontal deflection from single unit T
47. in detail either in this manual or in the manuals for the individual plug in units Contact your Tektronix Field Office or represen tative for assistance in making specific measurements with this instrument The following books describe oscilloscope measurement techniques which can be adapted for use with this instrument John D Lenk Handbook of Oscilloscopes Theory and Application Prentice Hall inc Englewood Cliffs New Jersey 1968 Operating Instructions 7934 Operator s J Czech Oscilloscope Measuring Techniques Springer Verlag New York 1965 J F Golding Measuring Oscilloscopes Transatiantic Arts inc 1977 Charles H Roth Jr Use of the Oscilloscope pro grammed text Prentice Hall inc Englewood Cliffs New Jersey 1970 Vertical Amplifier Plug in Units All 7A Series plug in units except the 7A21N unit can be used with the 7934 Bandwidth and sensitivity ranges should be taken into consideration when selecting amplifier plug in units Single Trace Any single channel amplifier will display a signal with the sweep provided by any 7B Series time base plug in This combination leaves two unused compartments available for other special purpose units Blank plug in panels are available to cover any unfilled plug in compartments Dual Trace A dual channel amplifier in either vertical compartment can display two separate signals with the other vertical compartment free for othe
48. is produced by the A time base unit Set the sweep rate of the A time base unit to 50 milliseconds division no tice that the display alternates between the left and right amplifier plug in units after each sweep Turn the A time base sweep rate switch throughout its range notice that the display alternates between amplifier units at all sweep rates 20 Set the VERTICAL MODE switch to CHOP Turn the A time base unit sweep rate switch throughout its range Notice that a dual trace display is presented at all sweep rates and that both amplifier units are displayed by the A time base unit on a time sharing basis Set the A time base unit sweep rate switch to 0 5 millisecond division 21 Set the VERTICAL MODE switch to ADD The dis play should be four divisions in amplitude Notice that the position control of either amplifier unit moves the display Set the VERTICAL MODE switch to LEFT Horizontal Deflection System 22 Notice that the position control of only the A time base unit affects the horizontal position of the displayed trace Position the start of the trace to the left graticule line with the A time base unit position control 23 Set the HORIZONTAL MODE switch to B Advance the B INTENSITY control until the display becomes defocused The defocused display indicates that the B IN TENSITY control is set too high Reduce the setting of the B INTENSITY control to obtain a bright well defined display 24 Notice that only
49. lable op tion is given in the following discussion Option information is incorporated into the appropriate sections of this manual Refer to Table 3 1 and the Table of Contents for location of option information For further information on instrument options see your Tektronix Products Catalog or contact your local Tektronix Field Office or representative WARNING To avoid electric shock hazard operating personnel must not remove the protective instrument covers Component replacement and internal adjustments must be made by qualified service personnel only OPTION 02 The X Y Delay Compensation network equalizes the sig nal delay between either vertical compartment and the B HORIZ compartment When this network is installed and activated the phase shift between the vertical and B hori zontal channels is adjustable to less than 2 from dc to 1 megahertz This option can be added at any time Order Tektronix number 040 0942 01 from your local Tektronix Field Office or representative OPTION 03 With Option 03 installed the instrument will meet EMC electromagnetic compatibility specifications given in Sec tion 1 This option can be added at any time Order Tektronix number 040 1195 00 from your local Tektronix Field Office or representative instrument Options 7934 Operators instrument Option Option 02 Provides X Y Delay Compensation Option 03 Provides EMC 3 2 Table 3 1 OPTION INFORMATION LOC
50. led instructions for replacing assemblies subassemblies and individual compo nents Section 6 Checks and Adjustments contains proce dures to check the operational performance and electrical characteristics of the instrument Procedures aiso include methods for adjustment of the instrument to meet specifications Section 7 Replaceable Electrical Parts contains in formation necessary to order replaceable parts and assem blies related to the electrical functions of the instrument Section 8 Diagrams and Circuit Board Illustrations includes detailed circuit schematics locations of assembled boards within the instrument voltage and waveform in formation circuit board and schematic component locators and locations of adjustments to aid in performing the adjust ment procedure Section 9 Replaceable Mechanical Parts includes information necessary to order replaceable mechanical parts and shows exploded drawings which identify assemblies INSTALLATION initial Inspection This instrument was inspected both mechanically and electrically before shipment it should be free of mars or scratches and should meet or exceed all electrical specifica tions To confirm this inspect the instrument for physical damage incurred in transit and test the electrical perfor mance by following the Operator s Checkout Procedure in the Operating Instructions Section 2 and the Performance Check given in Checks and Adjustments Section
51. mation 7934 Operators Table 1 5 ENVIRONMENTAL information NOTE This instrument will meet the electrical characteristics given in the Performance Requirement column of Table 1 4 over the following environmental limits Temperature Range Operating Nonoperating Altitude Operating Nonoperating EMC Electromagnetic Compatibility All Instruments Option 03 Vibration Shock Bench Handling Transportation Bounce Drop Packaged Product Humidity Electrostatic Discharge Operating Nonoperating 0to 50 C 55 to 75 C 5 kilometers 15 000 feet Test limit 15 kilometers 50 000 feet Meets requirements of MIL STD 461A when tested in accordance with the following test methods of MIL STD 462 CS 01 CS 06 and CE 03 Part 4 Curve 1 NOTE The EMI mesh filter must be installed and any unused plug in compartments must be covered with a blank plug in panel EMC shielded in order to meet EMC specifications See Instrument Op tions section for additional information FCC Part 15 Subpart J Class A VDE 0871 Class B RS01 RS03 limited to 1 GHz REO2 Part 7 REO2 Part 4 Tested to MIL T 28800C Section 4 5 5 3 1 Type III Class 5 Style F Tested to MIL T 28800C Section 4 5 5 4 1 Type Ill Class 5 Style F Tested to MIL T 28800C Section 4 5 5 4 3 Type Ill Class 5 Style F Qualified under National Safe Transit Committee test procedure 1A Category Il NSTA Project 1A B 1 NSTA Project 1A
52. n ambient temperature be tween 20 and 30 C 2 The instrument is allowed a 30 minute warm up period 3 The instrument is operated in an environment that meets the limits described in Table 1 5 All specifications are valid in both Full Scan and Reduced Scan modes unless stated otherwise Any applicable conditions not listed above are expressly stated as part of the appropriate characteristic Table 1 4 ELECTRICAL CHARACTERISTICS Characteristic Performance Requirement VERTICAL SYSTEM Deflection Factor Difference Between Vertical Compartments 196 or less Low Frequency Linearity Compatible with all 7000 series plug in units 0 1 division or less compression of a center screen two division display positioned anywhere vertically within graticule area Bandwidth Varies with plug in unit selected See 7934 Oscilloscope Vertical System Specification Table 1 8 isolation Between Vertical Compartments All Vertical Modes Delay Line At least 100 1 from dc to 150 MHz and at least 30 1 from 150 MHz to 500 MHz Permits viewing the leading edge of triggering signal NOTE Not all 7B50 series time base units can display the leading edge of the trigger signal in the 7934 Refer to the Tektronix Products Catalog under the specific time base unit for recommended mainframe use Vertical Display Modes Selected by front pane VERTICAL MODE switch LEFT g Signal from left vertical plug in unit displayed AL
53. n must be made before making connection to the instrument s input or output terminals Do Not Remove Instrument Covers To avoid electric shock hazard operating personnel must not remove the protective instrument covers Component replace ment and internal adjustments must be made by qualified service personnel only Do Not Remove CRT implosion Shield Do not remove the clear plastic implosion shield covering the crt face plate This crt implosion shield provides protection to the operator from crt implosion 7934 Operators Do Not Operate in Explosive Atmosphere To avoid explosion do not operate this instrument in an explosive atmosphere unless it has been certified for such operation CAUTION Refer fuse replacement to qualified prersonnel only To avoid fire hazard use only the fuse specified in the parts list for your in strument and which is identical in the following respects Use the Proper Fuse A Type Slow blow fast blow etc B Voltage rating 250 V etc C Current rating Operating Power Considerations To prevent damage to the instrument always check the LINE VOLTAGE SELECTOR switch located on the rear of the instrument before connecting the instrument to the supply circuit Exercise Care with Intensity Level Crt phosphor damage can occur under adverse conditions Avoid any condition where an extremely bright sharply focused dot exists on the crt Also remember that the light filter reduces the apparent light o
54. n on screen display 7 Connect the CALIBRATOR output to the input of the left amplifier unit with a 42 inch BNC cable 8 Set the left amplifier unit deflection factor to display a signal amplitude of two divisions centered on the screen 9 Set the A horizontal time base triggering for a stable display Display Focus 10 Rotate the FOCUS control and observe the square wave display Notice that the thickness of the trace varies as the FOCUS control is rotated Set the FOCUS conirol for a well defined trace if a well defined trace cannot be ob tained adjust the ASTIG screwdriver adjustment along with the FOCUS control for the best trace Trace Alignment 11 Disconnect the input signal Use the left amplifier unit position contro to align the trace with the center hori zontal graticule line H necessary set the TRACE ROTA TION adjustment so the trace is parallel to the center graticule line Graticule lllumination 12 Rotate the GRAT ILLUM control throughout its range and notice that the graticule lines are illuminated as the control is turned clockwise Control illumination 13 Set the rear panel CONTROL ILLUMINATION switch to HIGH Notice that the A INTENSITY indicator and the lighted pushbutton switches are illuminated Sequen tially press all of the HORIZONTAL MODE switch positions and notice the A and B INTENSITY lights these lights indi cate which intensity control is active Set the CONTROL ILLUMINATION swi
55. n set the PERSIS TENCE control to midrange just long enough for the display to fade out Quickly turn the PERSISTENCE control fully counterclockwise Slowly increase the STORAGE LEVEL clockwise and notice that the faded display again becomes visible against the background 52 Turn the PERSISTENCE STORAGE LEVEL and A INTENSITY controls fully counterclockwise and set the time base unit for auto triggering at a sweep rate of 0 5 second division 53 Set the PERSISTENCE control to midrange and slowly increase the A INTENSITY clockwise until the trace appears Vary the PERSISTENCE control setting and notice that the trace can be made to build up or fade more quickly depending on the control setting Varying the A INTENSITY control also affects the display in the same manner Return the PERSISTENCE control to midrange and slowly de crease the A INTENSITY control to the point where the trace is just extinguished then set the STORAGE LEVEL control fully clockwise and notice that the trace becomes visible again 54 Turn the PERSISTENCE STORAGE LEVEL and A INTENSITY controls fully counterclockwise and set the time base unit for auto triggering at a sweep rate of 0 5 millisecond division 55 Press the FAST BISTABLE button 56 Press the ERASE button and notice that the screen background appears to alternate between bright and dim This indicates that the sweep and transfer functions are op erating 57 Set the MULTI TRACE DELAY
56. n units are calibrated to the graticule so that accurate measurements can be made from the crt in either full or reduced scan mode The illumination of the graticule lines can be varied with the GRAT ILLUM control Figure 2 3 shows the graticule and defines the various measurement lines The terminology defined here will be used in all discussions involving measurements from the graticule The 0 10 90 and 100 markings on the left side of the graticule are provided to facilitate rise time measurements SECOND CENTER TENTH VERTICAL VERTICAL VERTICAL LINE LINE LINE CENTER HORIZONTAL LINE Figure 2 3 Definition of graticule measurement lines Operating Instructions 7934 Operator s Light Filter The tinted crt face plate filter minimizes light reflections from the face of the crt to improve contrast when viewing the display under high ambient light conditions This filter may be removed for waveform photographs or for viewing high writing rate displays To remove the filter pull outward on the bottom of the plastic crt mask and remove it from the crt bezel Remove the tinted filter leave the clear plastic face plate protector installed and replace the mask The face plate protector should be left in place at all times to protect the crt face plate from scratches and to protect the operator from crt implosion WARNING Do not remove the clear plastic implosion shield cov ering the crt face plate the crt
57. nd set the AUTO ERASE control fully counterclockwise into the detent position 46 Press the ERASE button The calibrator signal should be stored on the screen If not increase the A IN TENSITY control slightly and press the ERASE button again Repeat this sequence until a stored display is obtained 47 Press the SAVE button The signal stored in the pre vious step should remain on the screen it may be neces sary to adjust the SAVE INTENSITY control to view the display Turn the SAVE INTENSITY contro throughout its range and observe the effect on the display 48 Press the ERASE button Notice that the display cannot be erased the SAVE mode inhibits the erase func tion Press and release the SAVE button 49 Set the STORAGE LEVEL and the PERSISTENCE controls fully counterclockwise Press the VAR PERSIST button Observe that an erase cycle and sweep occurs when switching between the BISTABLE and VAR PER SIST modes and that the screen goes dark except for the stored display 2 9 Operating Instructions 7934 Operator s 50 Slowly turn the PERSISTENCE control clockwise and notice that the stored display fades into the background background lighting will be observed as the PERSISTENCE control is advanced clockwise The PERSISTENCE control determines the time interval during which the stored display is retained in the VAR PERSIST mode Set the PERSIS TENCE control fully counterclockwise 51 Press the ERASE button the
58. ng in either bistable or vari able persistence mode resulting in the FAST BISTABLE and FAST VAR PERSIST modes In either of the FAST modes the writing speed is adjusted by the STORAGE LEVEL control as well as the crt INTEN SITY controls Maximum stored writing speed in both FAST storage modes is attained by setting the STORAGE LEVEL and INTENSITY controls fully clockwise Erase In all storage modes an erase cycle removes any previous display from the storage target This prepares the storage and fast targets in the FAST storage modes to receive the next waveform Erase cycles are initiated by pressing the ERASE button grounding the rear panel RE MOTE ERASE INPUT or by rotating the AUTO ERASE control out of the OFF detent position The AUTO ERASE control can be set to erase the storage display in 1 to 10 second intervals WARNING Electric shock hazard Only qualified service person nel should internally modify the operation of the instrument Two modes of operation are available for the AUTO ERASE function either Erase After Sweep or Periodic Erase selection jumper located behind right side panel re fer selection of mode to qualified personnel oniy The two modes differ in the following ways The Erase After Sweep mode requires that the displayed time base unit complete a sweep in order to initiate the delay interval prior to the era sure the Periodic Erase mode repetitively erases indepen dent of the displaye
59. normalized to allow plug in units to be interchanged among plug in compartments without readjustment of the system The basic calibration of the plug in units should be checked when installed to verify their accuracy refer to the operating instructions in the plug in rnanual CONTROLS AND CONNECTORS The 7934 front and rear panels are shown in Figure 2 1 and Figure 2 2 A brief functional description of each control and connector is included in these illustrations Refer to De tailed Operating Information for additional information Front Panel Color Coding The 7934 front panei is color coded to define areas by function Blue identifies controls that affect the display mode green identifies triggering controls Other colors such as gray orange and yellow have no functional assignment but indicate a relationship among controis and or connectors OPERATOR S CHECKOUT PROCEDURE The Operator s Checkout Procedure may be used to ver ify proper operation of the controls and to get acquainted with the instrument Only instrument functions not mea surement quantities or specifications are checked in this procedure therefore a minimum amount of test equipment is required If performing the Operator s Checkout Proce dure reveals improper performance or instrument malfunc tion first check the operation of associated equipment then refer to qualified service personnel for repair or adjustment of the instrument Test Equipment Req
60. ohm 50 mV unit of time selected by time base unit time division switch within 1596 100 ns division sweep rate maximum 1 V unit of time selected by time base unit time division switch within 1096 1 ws division sweep rate maximum Approximately 950 ohms Characteristic Gate Output Source A Gate B Gate Diy d Gate Polarity Aor B Gate A Dly d Gate Output Voltage Into 50 Ohms Into 1 Megohm Rise Time Into 50 ohms Output Resistance Vertical Signal Out Source Output Voltage into 50 Ohms into 1 Megohm Bandwidth into 50 Ohms DC Centering Aberrations Output Resistance External Z Axis Input Polarity and Sensitivity Low Frequency Response input Resistance Maximum Input Voltage Maximum Repetition Rate General Information 7934 Operators Table 1 4 cont Performance Requirement Selected by internal Gate Selector jumper A HORIZ time base unit or B HORIZ time base unit Derived from the A HORIZ time base unit main gate Derived from the B HORIZ time base unit main gate Derived from the A HORIZ time base unit delayed gate Positive going with baseline at 0 V within 1 0 V into 1 Megohm Positive level when A time base delayed sweep or B sweep is enabled O V within 1 0 V into 1 Megonm when sweeps are disabled Output is always positive when no plug in is used or plug in does not provide delayed gate 0 5 V within 10 10 V within 10 up to 1 us division sweep rate 20 nanoseconds o
61. omatic erase mode ERASE Erases stored display PERSISTENCE Controls rate of continuous erasure of VAR PERSIST and FAST VAR PERSIST storage display modes 21 SAVE INTENSITY Controls intensity of the SAVE display 22 Ground not labeled Binding post to establish common ground between associated equipment 23 B TRIGGER SOURCE Selects internal trigger source for B HORIZ plug in unit VERT TRACE SEPARATION B Vertically positions the B HORIZ trace with respect to the A HORIZ trace duai sweep modes only 25 HORIZONTAL MODE Selects source of horizontal signal and horizontal display mode A TRIGGER SOURCE Selects internal trigger source for A HORIZ plug in unit 27 Horizontal Selector located at rear of A HORIZ compartment Three position switch which over rides the HORIZONTAL MODE switch to determine the source of the horizontal display signal VERTICAL MODE Selects source of vertical input signal and vertical display mode POWER switch and indicator Switch controls power to instrument indicator illuminates when power is applied CALIBRATOR Provides calibrated square wave voltages at 1 kHz repetition rate at CALIBRATOR output connector Fig 2 ib Front panel controls connectors and indicators Operating Instructions 7934 Operator s 2 4 DANGEROUS VOLTAGES INSIDE INSTRUMENT REFER SERVICING TO QUALIFIED PERSONNEL LA p P sA H H ons i
62. or complete writing of the waveform display Some experimentation may be necessary to establish the correct level Too high a setting of the READOUT intensity control will result in a broad poorly defined photograph of the read out display 3 If single shot photography is used set the READOUT intensity control to the PULSED position see Readout Dis play for complete operating information Then the readout is displayed in a single shot manner after the trace is com plete be sure the camera shutter remains open at least 0 5 second after the sweep is completed to photograph the en tire readout Also set the GRAT ILLUM control counter clockwise while the trace is being photographed Then the graticule can be photographed later to produce a double exposed picture showing the complete information intensity Modulation Intensity Z axis modulation can be used to relate a third item of electrical phenomena to the vertical Y axis and the horizontal X axis coordinates without affecting the wave shape of the displayed signal This is accomplished by changing the intensity of the displayed waveform to provide a gray scale display The voltage amplitude required for visible trace modula tion depends on the setting of the A and B INTENSITY con trols A two volt peak to peak signal will completely blank the display even at maximum intensity levels lower arnpli tude signals can be used to change only the relative trace brightness
63. oscil loscopes provide displays of fast changing signals that can not be examined using any other method For example sampling systems available for the 7934 can resolve repeti tive signals having less than 10 millivolts of peak amplitude and occurring in less than 1 nanosecond The technique used for sampling is very similar in princi ple to the use of stroboscopic light to study fast motion Samples of successive waveforms are taken amplified by a relatively low bandwidth amplifier and then displayed on the crt as a replica of the sample waveforms Three sampling systems are available at this time for the 7934 1 the 7812 which provides time domain reflectome try displays for general purpose measurements 2 the 7811 7T11A system and 3 the 7514 a dual channel verti cal sampling system including main and delayed sweep functions See the Tektronix Products Catalog to determine the characteristics of the individual units mentioned and of additional units made available after this manual is published Singie Trace Sampling A single trace sampling display requires either a double width 7812 which includes a time base or the 7811 sampling unit and the 7T11A sampling sweep unit Direct interconnections between the 7511 and the 7T11A require these units to be adjacent with the 7511 in the RIGHT VERT compartment and the 7T11A in the A HORIZ compartment If either the 7512 or the 7514 is used it must be located in the middle t
64. quency as the control is turned clockwise 66 Return the ERASE control to the detent OFF posi tion and set the time base unit for single sweep and external triggering Turn the SAVE INTENSITY control fully counterclockwise 67 Press the ERASE button notice that no sweep occurs 68 Press the SAVE button notice that no sweep occurs this is the Auto Save mode Since no trigger was avail able the sweep did not run therefore the system waits in a ready to store mode 69 Set the time base unit to internal trigger and notice that the screen goes dark This indicates that a sweep has occurred and that the system has entered the SAVE mode 70 Turn the SAVE INTENSITY control clockwise and notice that the stored display becomes visible 71 Press the STORE OFF button and set the time base unit for auto triggering This completes the Operator s Checkout Procedure for the 7934 DETAILED OPERATING INFORMATION Graticule The graticule is marked on the inside of the cri faceplate providing accurate parallax free measurements The grati cule is divided into eight vertical and ten horizontal divisions Each full scan division is 0 9 centimeter square divided into five minor divisions along each axis A reduced scan grati cule is etched in the center of the full scan graticule Each reduced scan division is exactly one half of a full scan divi sion 0 45 centimeter The vertical gain and horizontal tim ing of the plug i
65. r less Approximately 950 ohms Selected by B TRIGGER SOURCE switch Same as B TRIGGER SOURCE 25 mV division of vertical deflection within 25 0 5 V division of vertical deflection within 2596 Varies with vertical plug in selected see 7934 Oscilloscope Vertical System Specification Table 1 8 0 V within 1 V into 1 megohm 25 or less p p within 2 nanoseconds of step Approximately 950 ohms Z AXIS SYSTEM Positive 2 V provides complete blanking from maximum intensity condition negative 2 V provides complete unblanking from minimum intensity condition To dc Approximately 470 ohms Within 15 V dc plus peak ac 1 MHz General information 7934 Operators Characteristic Readout Modes Free Run Readout READOUT Control in Variable Area Storage Mode STORE OFF BISTABLE or VAR PERSIST FAST BISTABLE or FAST VAR PERSIST SAVE Pulsed Readout READOUT Control in PULSED Detent Storage Mode STORE OFF BISTABLE VAR PERSIST FAST BISTABLE FAST VAR PERSIST SAVE BISTABLE or FAST BISTABLE VAR PERSIST FAST VAR PERSIST Character Height Full Scan Reduced Scan 1 8 Table 1 4 cont Performance Requirement READOUT DISPLAY Selected by front panel READOUT control Readout continuously displayed Readout continuously displayed except turns off during erase cycie Readout continuously displayed except turns off at beginning of erase cycle or at initiation of single sweep reset un
66. r panei REMOTE ERASE INPUT signal Remote Save Input The SAVE storage mode can be entered into by applying a signal to the REMOTE SAVE INPUT connector The SAVE mode prevents accidental era sure and or additional storage of the stored display Remote Storage Gate Input The FAST BISTABLE and FAST VAR PERSIST storage modes can be externally con trolled by applying a gate signal to the REMOTE STORAGE GATE INPUT The positive going transition of the gate en ables the transfer storage mesh to retain the display The negative going transition transfers the display stored on the transfer storage mesh to the storage screen the display is not visible until transferred to the storage screen However if the displayed sweep starts before the positive transition of the remote storage gate the transfer storage mesh is en abled at the start of the displayed sweep Then the display stored on the transfer storage mesh will not be transferred until the displayed sweep has ended and the negative transi tion of the remote storage gate occurs APPLICATIONS The 7934 Oscilloscope and its associated plug in units provide a flexible measurement system The capabilities of the overall system depends mainly upon the plug in units selected for use with this instrument Specific applications for the individual plug in units are described in the plug in unit instruction manuals The overall system can also be used for many applications which are not described
67. r uses Three trace A duai channe amplifier can be used with any singie channel amplifier to display three separate sig nals If two time base plug in units are used in the horizontal compartments two signals can be displayed at one sweep rate while the third signal is displayed at the other sweep rate Four Trace Two dual channel amplifiers can display four separate signals if one time base unit is used all four signals will be displayed at the same sweep rate Time Base Plug In Units The 7934 is compatible with time base units of the 7B70 7B80 and 7B90 Series Sweep rates and triggering ranges should be taken into consideration when selecting time base plug in units To obtain a delayed sweep display a delaying time base unit must be installed in the A HORIZ compartment and a delayed time base unit installed in the B HORIZ compart ment if a dual time base unit is used a delayed sweep dis play can be obtained with one horizontal plug in unit in either horizontal compartment This leaves the other hori 2 21 Operating Instructions 7934 Operator s zontal compartment available for other plug in units as sug gested later in this section NOTE 7B50 Series time base units are not recommended for use with this instrument because they require a longer delay line than is in the 7934 Therefore the triggering event may not appear on the display Sampling Displays Sampling system plug in units for the 7000 Series
68. rating in the PULSED mode is set by the READOUT PRESET adjustment Readout Operation With Storage Each of the storage modes modify the operation of the Readout System to some extent Normai Readout Mode With the READOUT control set in the variable area the Readout System operates as follows Operating Instructions 7934 Operators BISTABLE and VAR PERSIST In the BISTABLE and VAR PERSIST storage modes the readout display is turned off during the storage erase cycle otherwise the Readout System operates as previously described under Readout Modes FAST BISTABLE and FAST VAR PERSIST in the FAST BISTABLE and FAST VAR PERSIST storage modes the Readout System turns off at the beginning of an erase cycle or when the single sweep time base mode is reset and re mains off until the end of the storage transfer cycle In addi tion the Readout System is held off whenever the MULTI TRACE DELAY control is in operation out of its detent posi tion and the displayed time base unit is in a repetitive sweep mode Pulsed Readout Mode With the READOUT control set to PULSED the Readout System operates as follows BISTABLE In the BISTABLE storage mode the readout display runs continuously however the Readout System turns off when the storage erase cycle begins and remains off until the end of the first displayed sweep VAR PERSIST In the VAR PERSIST storage mode one complete frame of readout is displayed after the displayed
69. res the fast target to store another display and sends an additional single sweep reset command to the time base unit s After the multi trace cy cle the time base unit s can again sweep once after which it is again locked out and the transfer function occurs When the time base unit s is operated in other than a single sweep mode the multi trace cycle is controlled by the MULTI TRACE DELAY control If the MULTI TRACE DE LAY control is set to its detent position operation is as previously described for the single sweep mode If the MULTI TRACE DELAY control is out of the detent position the multi trace cycle is triggered automatically following the transfer cycle The length of the cycle can be varied by the MULTI TRACE DELAY control over a range from approxi mately 600 milliseconds to more than four seconds Save Mode The SAVE mode can be entered from any storage mode by pressing the SAVE button or by grounding the rear panel REMOTE SAVE INPUT The indicator next to the SAVE button illuminates when the SAVE mode is acti vated When in the SAVE mode the time base unit s and readout system are inhibited and the display cannot be erased The SAVE INTENSITY control adjusts the intensity of the saved display Minimum intensity provides the great est viewing time in the VAR PERSIST and FAST VAR PER SIST modes and although the view time of the BISTABLE and FAST BISTABLE storage modes is very long without the use of the SAVE mode the
70. ruction manuals In addition the calibrator can be used as a convenient signal source for application to external equipment Voltage The CALIBRATOR provides accurate output voltages of 40 millivolts 0 4 volt and 4 volts into high impedance loads In addition it provides 4 millivolts 40 milli volts and 0 4 volt into 50 ohm loads Current The optional current loop accessory provides a 40 milliamp output current the CALIBRATOR must be set for 4 volt output which can be used to check and calibrate current measuring probe systems The current signal is ob tained by clipping the probe around the current loop Repetition Rate The repetition rate of the CALIBRA TOR is 1 kilohertz The calibrator circuit uses frequency stable components to maintain accurate frequency and a constant duty factor Thus the CALIBRATOR can be used for checking the basic sweep timing of time base units Wave Shape The square wave output signal of the CALIBRATOR can be used as a reference wave shape Operating Instructions 7934 Operator s when checking or adjusting the compensation of passive high resistance probes The square wave output from the CALIBRATOR has a flat top any distortion in the displayed waveform is due to the probe compensation Signal Outputs Sawtooth Out The SAWTOOTH OUT connector provides a positive going sawtooth signal derived from the time base unit installed in the A HORIZ compartment or from the time base unit in
71. rue time relationship However if the signals are not time related the display from the plug in that is not providing a trigger signal will be unstable on the crt When the ALT vertical mode is selected and either the ALT or CHOP button of the HORIZONTAL MODE switch is selected the instrument operates in the slaved alternate mode Under this condition the signal from the LEFT VERT unit is always displayed at the sweep rate of the B HORIZ time base unit and the signal from the RIGHT VERT unit is displayed at the sweep rate of the A HORIZ time base unit non delayed sweep only This results in two displays that are completely independent as to vertical deflection and sweep rate This display is equivalent to the display obtain able with a dual beam oscilloscope for most repetitive display combinations If delayed sweep operation is used with this mode a dif ferent sequence is displayed First the LEFT VERT unit is displayed at the sweep rate of the A HORIZ time base unit delaying sweep and then at the sweep rate of the B HORIZ time base unit delayed sweep The vertical display then shifts to the RIGHT VERT unit and its signal is displayed consecutively at the delaying and delayed sweep rates Chopped Mode The CHOP position of the VERTICAL MODE switch produces a display which is electronically switched between channels at about a one megahertz rate In general the CHOP mode provides the best display at sweep rates slower than about
72. set whereas both main and delayed sweeps are required to generate a holdoff pulse 7L9 set for stored display mode 7934 storage modes do not operate normally no pulsed readout display 71 5 Sweep Gate remains Hl 715 set for non storage mode with manual or normal sweep Single sweep reset or erase causes 7L5 to operate in single sweep mode 7L5 control logic 7L5 single sweep logic line pulses when single sweep reset occurs causing logic to oscillate 7L5 set for non storage mode with 7934 set for fast storage mode and MULTI TRACE DELAY operation Crt display flashes General information 7934 Operators Table 1 7 cont Piug In Unit Operating Conditions Symptoms Cause 71 12 Any 7934 storage mode with 7L12 will not automatically reset 7L12 single sweep logic output is 7L12 set for single sweep after an erase or multi trace always LO operation cycle 7934 fast storage modes with Storage display will not remain MULTI TRACE DELAY control viewable operational 71 13 7934 fast storage modes with 7L13 will not activate multi trace 7L13 does not provide single sweep 7113 set for single sweep function reset operation 7812 7812 set for single scan 7812 will not start by remote 7512 does not provide single operation reset or camera reset or after an sweep reset erase c
73. st of the time base units with the amplifier function the X horizontal de flection signal can be connected either to an external input connector on the time base unit or it can be routed to the time base unit through the internal triggering system see time base instruction manual for details If the latter method is used the A and B TRIG SOURCE switches must be set so that the X horizontal deflection signal is obtained from one of the vertical amplifier units and Y vertical deflection signal is obtained from the other vertical unit The attenuator switch on the amplifier unit can provide the horizontal with a preconditioned signal compatible with the horizontal deflec tion factor Also plug in units need not be moved from one compartment to another to change from X Y operation to other modes of operation Operating Instructions 7934 Operator s The Horizontal Selector switch located behind the metal shield at the rear of the A HORIZ compartment provides a method of storing X Y displays using the FAST BISTABLE or FAST VAR PERSIST storage modes Details on use of this switch to store X Y displays is given under Horizontal Selection earlier in this section Raster Displays A raster type display can be used effectively to increase the apparent sweep length For this type of display the trace is deflected both vertically and horizontally by saw tooth signais This is accomplished in the 7934 by installing a 7B Series time base
74. stalled in the B HORIZ compartment WARNING Electric shock hazard present Only qualified service personnel should internally modify the operation of this instrument it is possible to select either the A HORIZ or the B HORIZ compartment as the source of the sawtooth output signal selection jumper located behind the right side panel refer selection to qualified service personnel only The 7934 is set to A HORIZ at the factory The unit of time for the sawtooth output is determined by the setting of the time base unit Time Division switch Refer to Table 1 4 in the General information section for signal parameters Gate Out The GATE OUT connector provides a positive going rectangular pulse which is derived from a time base unit installed in either horizontal plug in compartment WARNING Electric shock hazard present Only qualified service personnel should internally modify the operation of this instrument The Gate Out signal can be selected from the time base unit installed in the A HORIZ compartment or B HORIZ compartment selection jumper located behind the right side panel refer selection to qualified service personnel only The 7934 is set to A HORIZ at the factory The duration of the GATE OUT signal is the same as the duration of the respective sweep or in the case of the delayed gate it starts at the end of the delay period and lasts until the end of the sweep from the delaying time base unit Amplit
75. tal readout plug in units to operate with other plug in units makes it possible to process and monitor signals at the same time the digital measurement is being made For example by locating a frequency counter in one of the vertical compartments and an amplifier unit in the other vertical compartment the crt can display the trigger waveform superimposed on the displayed signal to indi cate the actual triggering point Or if the counter is placed in a horizontal compartment a low amplitude signal can be applied to a vertical amplifier and amplified before it is inter naily routed by the trigger source switches to the counter trigger circuit This allows the unit to be used on signals too small to trigger other counters Readout Access Plug In Unit The 7M13 Readout plug in unit provides front panel keyboard operation for conve nient access to the crt readout characters This allows information such as dates and identifying nomenclature to be displayed on the crt with the normal crt display This capability is particularly useful when making photographs Transistor Curve Tracer Plug in Units The 7CTIN Curve Tracer plug in checks small signal transistors and di odes by producing a display showing the basic characteris tic curves for the device being tested Stepped sweep signals from an internal power supply are applied to the device under test The resulting output signals are in turn applied to the horizontal and vertical deflec
76. tch to the MEDIUM position Observe that the selected intensity indicator and the lighted push button switches on the plug in units are dimmed Set the CONTROL ILLUMINATION switch to OFF and notice that the selected intensity indicator and pushbutton switches are extinguished 14 Set the rear panei CONTROL ILLUMINATION switch to the HIGH position Return the HORIZONTAL MODE switch to A Vertical Deflection System 15 Connect the 4 V CALIBRATOR output to the input connectors of both amplifier units with two 42 inch BNC cables and a BNC T connector Set the deflection factor of the left amplifier unit to display about two divisions of signai on the screen 16 Notice that the position control of only the left ampli fier unit affects the vertical position of the displayed trace Position the trace to the upper haif of the graticule Operating Instructions 7934 Operator s 17 Set the VERTICAL MODE switch to RIGHT Set the deflection factor of the right amplifier unit to display about two divisions of signal on the screen 18 Notice that the position control of only the right am plifier unit affects the vertical position of the displayed trace Position the trace to the lower half of the graticule 19 Set the VERTICAL MODE switch to ALT Notice that two traces are displayed on the screen The top trace is produced by the left amplifier unit and the bottom trace is produced by the right amplifier unit the sweep for both traces
77. ten or unwritten In this mode only the A or B INTENSITY controls affect the stored writing speed writing speed is quite low but the stored view time is indefinitely iong Variable Persistence Storage In the VAR PERSIST mode points on the storage target can vary in luminance between totally dark and very bright in this mode writing speed is greater than in the BISTABLE mode but the stored display is essentially unstable or continuously fading away The rate of fading is adjusted by the PERSISTENCE con trol The VAR PERSIST storage mode is particularly useful for viewing high speed repetitive signals with low repetition rates The PERSISTENCE control can be adjusted in con junction with the STORAGE LEVEL and INTENSITY con trols to produce a steady bright trace Writing speed is varied in this mode by the STORAGE LEVEL control as well as the crt INTENSITY controls Maximum stored writing speed is achieved by setting the INTENSITY controls and the STORAGE LEVEL control fully clockwise Fast Storage The 7934 crt has a speciai high speed tar get known as the fast target located just behind the stor age target The fast target has an extremely high writing speed but retains images for oniy a fraction of a second For this reason images stored on the fast target are quickly and automatically transferred to the storage target this opera tion is called transfer storage Transfer storage can be used with the storage target operati
78. the B time base unit position control affects the horizontal position of the displayed trace Posi tion the start of the trace to the left graticule line with the B time base unit position control Set the B time base unit trig gering controls for a stable display 2 7 Operating Instructions 7934 Operator s 25 Set the HORIZONTAL MODE switch to ALT Two traces should be presented on the screen If the traces over lap adjust the VERT TRACE SEPARATION B control to position one trace to the bottom of the graticule area Tum the sweep rate switches of both time base units throughout their range Observe that each time base unit controls one of the traces independently of the other time base unit Also notice that when one of the time base units is set to a slow sweep rate below about 50 milliseconds division sweep alternation is evident only one of the traces is presented on the screen at a time Set the sweep rates of both time base units to 0 5 millisecond division Adjust the A INTENSITY control notice that it changes the intensity of the trace pro duced by the A time base unit only Likewise the B INTEN SITY control changes the intensity of the trace produced by the B time base unit only Return both intensity controls to desirable levels 26 Set the HORIZONTAL MODE switch to CHOP No tice that two traces are displayed on the screen in a manner similar to that of the ALT display Turn the sweep rate switches of both time
79. the BEAMFINDER button the display should remain within the graticule area Trace Alignment The TRACE ROTATION adjustment allows the trace to be aligned with the horizontal graticule lines To set trace alignment set the amplifier unit input coupling to ground Then position the trace to the center horizotal line and ad just the TRACE ROTATION adjustment so that the trace is parallel with the center horizontal graticule line Readout Display The Readout System provides an alpha numeric display of information on the crt along with the analog waveform display The information displayed by the Readout System is obtained from the plug in units installed in the plug in compartments The readout information from each channel of each plug in unit is called a word Up to eight words of readout in formation can be displayed on the crt two channels from each of the four plug in compartments The location of each readout word is fixed and is directly related to the plug in unit and channel from which it originated Figure 2 4 shows the area of the graticule where the readout from each plug in unit and or channel is displayed Notice that the readout from channel 1 of each plug in unit is displayed in the top division of the graticule and the readout from channel 2 is displayed directly below in the bottom division of the graticule LEFT VERT CHANNEL 1 RIGHT VERT CHANNEL 1 A HORIZ CHANNEL 1 B HORIZ CHANNEL 1
80. tice that the readout from a particular plug in occupies a specific location on the display area If either of the vertical plug in units is a duai trace unit notice that the readout for channel 2 ap pears within the lower division of the screen Return the VERTICAL MODE switch to LEFT and the HORIZONTAL MODE switch to A Set the READOUT control to OFF Beamfinder 38 Set the deflection factor of the left amplifier unit to 0 1 volt division Notice that a square wave display is not visible since the deflection exceeds the scan area of the crt 39 Press the BEAMFINDER button notice that the dis play is returned to the viewing area in compressed form while the BEAMFINDER is pressed Release the BEAMFINDER and notice that the display again disappears from the viewing area 40 With the BEAMFINDER button pushed in increase the amplifier unit deflection factor until the display is re duced to about two divisions vertically Adjust the position control of the displayed amplifier unit to position the com pressed display near the center of the graticule Release the BEAMFINDER and notice that the display remains within the viewing area Calibrator 41 Connect the CALIBRATOR output to both the left and right vertical units with two BNC cables and a BNC T connector The display amplitude should be approximately two divisions If not adjust the deflection factor accordingly 42 Press the different CALIBRATOR buttons labeled 4 V 0 4
81. til end of transfer cycle Also turns off when displayed time base operates in other than single sweep mode and MULTI TRACE DELAY control is not in detent Readout displayed for approximately one second after save mode is entered then turns off One frame of readout is provided at end of displayed sweep Readout continuously displayed except turns off from beginning of erase cycle until end of first displayed sweep One frame of readout is provided at the end of displayed sweep Erase cycle inhibits readout display Readout continuously displayed except turns off at beginning of erase cycle or at initiation of single sweep reset until end of transfer cycle Also turns off when displayed time base operates in other than single sweep mode and when MULTI TRACE DELAY control is not in detent One frame of readout is provided at the end of transfer cycle turns off when displayed time base operates in other than single sweep mode and when the MULTI TRACE DELAY control is not in detent Readout displayed for approximately one second after SAVE mode is entered then turns off Allows one frame of readout to be displayed at end of displayed sweep Allows one frame of readout to be displayed at end of transfer cycle 0 35 to 0 5 division At least 0 2 division Characteristic Cathode Ray Tube Graticule Type Area Full Scan Reduced Scan Phosphor Stored Vertical and Horizontal Resolution in VAR PERSIST and FAST VAR PERSIST
82. tion in the General Information section Probe Power The two PROBE POWER connectors on the rear panel provide operating power for active probe sys tems It is not recommended that these connectors be used as a power source for applications other than the compat ible probes or other accessories which are specifically de signed for use with this system Display Photography A permanent record of the crt display can be obtained with an oscilloscope camera system The instruction manual for the Tektronix Oscilloscope Cameras includes complete instructions for obtaining waveform photographs The crt bezel provides integral mounting for Tektronix Oscilloscope Cameras The three pins located on the left side of the crt bezel connect power to compatible camera systems Control signals can also be received from Tektronix automatic cameras to allow camera controlled single shot photography see camera manual for further information If the readout portion of the display is to be included on waveform photographs the following suggestions will aid in obtaining good photographs 1 Focus the oscilloscope display and the camera on the readout portion of the crt display The auto focus feature in this instrument will maintain the traces at optimum focus 2 20 2 Set the READOUT intensity control for the minimum setting that allows the characters to be written This nor mally occurs at a slightly lower intensity level than is neces sary f
83. tion of the crt display VERT SIG OUT Output signal derived from vertical signal as selected by the B TRIGGER SOURCE switch SAWTOOTH OUT Sawtooth output signal derived from the A or B time base unit GATE OUT Output signal derived from the A Gate B Gate or the A Dely d Gate REMOTE RESET IN Allows external single sweep reset of time base unit s Fig 2 2b Rear panel controis and connectors 2 5 Operating Instructions 7934 Operator s 1 Amplifier Unit two required Description Compatible with 7934 Oscilloscope One dual trace unit required to completely check vertical readout fields Type Any compatible 7A series units Refer to Table 1 8 in the General Information Section for suitable units 2 Time Base Unit two required Description Compatible with 7934 Oscilloscope One dual time base or delaying time base required to completely check horizontal readout fields Type Any compatible 7B series units Refer to Table 1 9 in the General Information section for suitable units 3 Sine Wave Generator Description Frequency range 250 kilohertz to 1 mega hertz output amplitude two volts peak to peak into 50 ohms waveform sine wave Type Tektronix SG 503 requires TM 500 power module 4 Cables two required Description Length 42 inches connectors BNC Type RG 58 U 50 ohm coaxial Tektronix Part 012 0057 01 5 BNC T Connector Description Connectors two BNC femal
84. tion systems of the oscilloscope to plot a family of characteristic curves This plot can be used to check for damaged transistors and diodes or to select for special or matched characteristics and to calculate gain leakage breakdown voltage etc wal Spectrum Analyzer Plug in Units The 7000 Series spectrum analyzer plug in units display applied signal ampli tudes dispersed over portions of the rf spectrum Absolute signal energy is plotted on the vertical axis against fre quency on the horizontai axis Applications include wave form and distortion analysis EMC and random noise measurements filter design spectrum surveillance etc X Y Operation In some applications it is desirable to display one signal versus another X Y rather than against time internal sweep The flexibility of the amplifier plug in units available for use with the 7934 provide the means of applying exter nal signals to the horizontal deflection system installation of a 7A Series amplifier plug in unit in one of the horizontal and one of the vertical compartments pro vides X Y operation For further information refer to the horizontal specifications in this manual and to the individual instruction manuals for the amplifier units Some of the 7B Series time base units can be operated as amplifiers in addition to their normal uses as time base generators This feature allows an external signal to provide the horizontal deflection to the crt For mo
85. ude of the output signal at the GATE OUT connector is about 0 5 volt into 50 ohms or about 10 volts into 1 megohm Vertical Signal The VERT SIG OUT connector provides a sample of the vertical deflection signal The source of the 2 19 Operating Instructions 7934 Operators output signal at this connector is determined by the B TRIG GER SOURCE switch In the VERT MODE position of the B TRIGGER SOURCE switch the output signal is determined by the setting of the VERTICAL MODE switch The output signal in the LEFT and RIGHT positions of the VERTICAL MODE switch is obtained only from the selected vertical unit In the ALT position of the VERTICAL MODE switch the output signal at the VERT SIG OUT connector switches between signals from the two vertical units along with the crt display However the vertical output signal in the CHOP position is a composite signal and is the same as that ob tained in the ADD position due to the requirements of the triggering system The LEFT VERT and RIGHT VERT posi tions of the B TRIGGER SOURCE switch are independent of the selection of the VERTICAL MODE switch and provide the vertical output signal only from the selected vertical unit even when it is not selected for display The output voltage into a 50 ohm load is about 25 millivolts division of crt display into a 1 megohm load The output signal frequencies are determined by the vertical plug in unit used see Table 1 8 Vertical System Specifica
86. uired The following test equipment is required for the Operators Checkout Procedure Other test equipment which meets these requirements may be substituted When other equipment is substituted the control settings or setup may need to be altered Operating Instructions 7934 Operator s YO CD CO O 60 10 AA 00 o Bg ftAMFINDER INTENSITY SE 3 x Sch pn Y y S ema dn d E ei ES Sys bal WU See ro y e 1 gi RATI a A Nasi pom 2832057 LALIBNSTEN TIMEIAN erer HG D C9 2 2 TRIGGER P TRIGGER SOURCE e B source eR ue PE q EAT LA noo S Y D opt Me 1 e mper or Ng be TD HI veer do VERT TRACE ES A uc SEPARATION S ri p H Ed ew VERTICAL MODE PR HORON AL MODE iE an A E Bi e NI E g VLL LEET Ven BIGHT vrt KOLA OBIT OELAYING TIME GABE nl c B HORIZ 8 NOTE BOBBO O O HORIZONTAL SELECTOR SWITCH LOCATED AT THE REAR OF THE A HORIZ COMPARTMENT Fig 2 1a Front panei controls connectors and indicators Operating Instructions 7934 Operator s FRONT PANEL CONTROLS CONNECTORS AND INDICATORS Q GRAT ILLUM Controls illumination of graticute lines 2 PRESET Readout Screwdriver adjustment to set PULSED Readout Mode intensity 3 READOUT Controls brightness of the readout display Disables Readout System in counterclockwise OFF detent Activates Pulsed Readout Mode in clockwise PULSED detent Camera Power Connector not labeled Three pin connector provid
87. unted on the bottom of the instru ment permits the instrument to be tilted up about 10 for more convenient crt viewing PACKAGING FOR SHIPMENT If the 7934 is to be shipped for long distances by com mercial transportation it is recommended that the instru ment be repackaged in the original manner The carton and packaging material in which your instrument was shipped should be saved and used for this purpose Also if this instrument is to be shipped to a Tektronix Service Center for service or repair attach a tag to the in strument showing the following Owner of the instrument with address name of a person at your firm who can be contacted if required complete instrument type and serial number and a detailed description of the service required if the original packaging is unfit for use or is not available package the instrument as follows 1 Obtain a corrugated cardboard shipping carton having inside dimensions at least six inches greater than the instru ment dimensions Refer to Table 1 3 for carton test strength requirements General information 7934 Operators TABLE 1 2 Power Cord and Plug Identification information Nominal Reference tion Line Voltage AC Standards Zen P d SR North American ANSI C73 11 271 H 120V 15A 120 V NEMA 5 15 P Standard EC 83 Ze a deena nike amon Universal Euro CEE 7 II IV VII 220V 6 16A 220 V YEC 83 A UK
88. ut of a sine wave generator to the input of the amplifier unit Set the sine wave generator repe tition rate to 1 kilohertz and the vertical amplifier deflection factor for a two division display 4 Set the time base unit sweep rate for 0 2 millisecond division and the triggering for a stable display Set the A INTENSITY control so the display is at a usable intensity level about midrange 5 Turn the FOCUS control fully counterclockwise and set the ASTIG adjustment to midrange 6 Set the FOCUS control so the thickness of the sine wave trace is as thin as possible 7 Adjust the ASTIG adjustment so the width of the sine wave trace is as thin as possible 8 Repeat steps 6 and 7 for the best overail focus Beamfinder The BEAMFINDER helps locate a display that overscans the crt viewing area vertically and or horizontally When the BEAMFINDER button is pressed the display is compressed and defocused within the graticule area To locate and repo sition an overscanned display use the following procedure 1 Press the BEAMFINDER button While the display is compressed change the vertical and horizontal deflection factors until the vertical deflection is about two divisions high and the horizontal deflection is about four divisions wide the horizontal deflection needs to be reduced only when operating in an X Y mode 2 Adjust the vertical and horizontal position controls to center the display on the graticule 3 Release
89. utput from the crt Prevent Instrument Damage Plug in units should not be installed or removed without first turning the instrument power off to prevent instrument damage 7934 Operators 7934 FEATURES The Tektronix 7934 Storage Oscilloscope is a solid state wide bandwidth instrument designed for fast writing speed storage applications Three display modes are available Nonstore Store and Save as well as four storage modes Bistable Variable Persistence Fast Bistable and Fast Variable Persistence In addition the Reduced Scan feature increases the stored writing speed capability The 7934 accepts up to four Tektronix 7000 series plug in units The flexibility of the plug in feature and variety of plug in units available allows the system to be used for many measurement applications The left pair of plug in compartments are reserved for vertical deflection and the right pair are reserved for horizontal deflection Electronic switching between each pair produces multi trace vertical and or horizontal displays Power supply voltages are closely regulated to maintain instrument performance when variations in line voltage line frequency or plug in load occur The light weight high efficiency power supply operates from 115 or 230 volt nominal supply sources 50 to 400 hertz Section 1 7934 Operators GENERAL INFORMATION INTRODUCTION Operator s Manual The Operator s Manual is divided into three main sections Se
90. wo compartments to make the proper connections with the 7934 Dual Trace Sampling Two 7911 plug ins can be used with a single sampling time base unit for time related dis plays of two signals Direct interconnections from the LEFT VERT 7811 pass through the RIGHT VERT 7511 to reach the A HORIZ time base unit The 7814 is a dual channel sampling unit with delaying sweep capability It must be used in the middle two plug in compartments 2 22 Dual trace sampling displays can also be made by a 7812 in the middie two compartments and a 7811 in the LEFT VERT compartment in this application the 7512 sup plies the time base for both traces X Y Sampling One 7811 inserted in the RIGHT VERT compartment and one in the adjacent A HORIZ compart ment automatically share a 50 kilohertz free running strobe condition specified for X Y displays The 7814 has an X Y operation incorporated as one of its normal mode functions Special Purpose Plug In Units Digital Counters and Multimeter Plug In Units The digi tal multimeter plug in units measure current voltage tem perature and resistance digital frequency counter plug in units measure frequency from dc to above 500 MHz These units make use of the readout system to display the mea sured information on the crt and can function in any com partment in combination with each other or with any other plug in units available for use with the 7934 oscilloscope system The ability of digi
91. wo traces Vertical deflection from both units horizontal deflection from both units Independent pairs sweep slaving operation see Alternate Mode discussion in this One trace Vertical deflection is algebraic summation of signals from both units horizontal deflection from single unit Two traces Vertical deflection is algebraic summation of signals from both units horizon tal deflection from both horizontal compartments Two traces Vertical deflection from both units horizontal deflection from single unit Four traces Vertical deflection from both units horizontal deflection from both units One trace Vertical deflection from single unit horizontal deflection from single unit Two traces Vertical deflection from single unit horizontal deflection frorn both units Combinations given for single channel vertical and horizontal units only 2 16 display at sweep rates below about 20 milliseconds division At these siower rates alternate mode switching becomes perceptible Alternate Mode displays have three types of triggering available When the A and B TRIGGER SOURCE switches are set to the VERT MODE positions each sweep is trig gered by the signal being displayed on the crt This provides a stable display of two unrelated signals but does not indi cate the time relationship between the signals In either the LEFT VERT or RIGHT VERT positions of the TRIGGER SOURCE switches the two signals are displayed showing t
92. ycie 7512 start button will not activate multi trace function 7934 fast storage modes with Storage display will not remain 7912 single sweep logic output is MULTI TRACE DELAY control viewable always LO operational and 7812 set for single scan 7814 7914 set for single scan mode 7934 storage modes and Sweep gate remains HI at the end PULSED readout do not operate of a scan Can be overcome by normally activating both the Rep and Single Scan buttons 79814 set for single scan 7914 will not start after an erase 7814 has no single sweep logic operation both Rep and Single cycle output Scan buttons activated 7934 fast storage modes with Storage display will not remain MULTI TRACE DELAY control viewable operable and 7514 set for single scan operation both Rep and Single Scan buttons activated 7T11A All SAVE AUTO ERASE PULSED 7T11A does not generate holdoff readout and fast storage modes do not operate normally 7T11A will not aiternate with other sweep plug ins pulses General information 7934 Operators 1 within 9 350 within 9 Table 1 8 7934 OSCILLOSCOPE VERTICAL SYSTEM SPECIFICATION Amplifier Bandwidih Rise Time Accuracy Vertical Signal Out Plug in Unit MHz ns 0 to 50 C Bandwidth Rise Time Ext Cal 6 Int Cal 96 MHz ns ma mega Jm Lu lo jn Jm Lag 105 3 4 100 3 5 P6130 1 5 2 5 2 3 P6022 120 100 3 5 44 70 5 0 P6087 140 2 5 7A18A None 100 3 5 2 3 90 4 7 500
93. ying a dc voltage to one channel to offset the dc component of a signal on the other channel The common mode rejection ratio between the vertical plug in compartments is at least 100 1 from dc to 150 megahertz The rejection ratio decreases to 30 1 from 150 to 500 megahertz The overall deflection on the crt in the ADD mode is the algebraic sum of the signals from the two vertical plug in units It is difficult to determine the voltage amplitude of the resultant display unless the amplitude of the signal applied to one of the plug ins is known This is particularly true when the vertical units are set to different deflection factors since it is not obvious which portion of the display results from the signal applied to a given plug in unit The polarity and repetition rate of the applied signals aiso affect the ADD display The following precautions should be observed when using the ADD mode 1 Do not exceed the input voltage ratings of the plug in units 2 Do not apply large signals to the plug in inputs A good rule is to not apply a signal of more than about eight times the vertical deflection factor For example with a verti cal deflection factor of 0 5 volts division the voltage applied to that plug in should not exceed four volts Larger voltages may result in a distorted display 3 To ensure the greatest dynamic range in the ADD mode set the position controls of the plug in units to a set ting which wouid result in a m

Tektronix Hunting Equipment 7934 User's Manual

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