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Hameg -- HM604

1. C627 1 50V HVTR H 4 uaa cb ho cut messer We R636 PWR Trafo S 10n 2KV A 5 624 shielded i Achtung Caution 1 6 1M Auf diesem Board entstehen This board generates high voltage PE 200 VR603 ber hrungsgef hrliche Spannungen Danger Do not touch K u G A Lebensgefahr 1005604 01 47 25V R649 Der Wandler ist geschirmt Converter is shielded WA FOCUS 7BmA 100 LM P min Der Wert dieses Bautels Ist _ Component volue is Intens abh ngig v d HVTR type dependent VR 57 1 ce 2 2 f 11 m 2 R651 5 650 1X2pF iXipF f BF311 pe KOHLE CARBON a R 66 ev 5 Z Board 6 63 cess ces HAMEB 33u 35V l 10 3 2 Date HM 604 Blatt Sheet of nderungen vorbehalten Subject to change without notice Datum Men 23 06 1988 J Waldschmitt eonou 12elqns ueBunispuy 709 88 0l CC Alle 1OuF Elkos haben 35V All 1 electrolytic Cap ore 35V types ALT Trig ALT Trig to X Y PCB pe From 2 gy Ext Trig Trig Alle haben 50 C3 blue Zu 1M 30p All ore SOV types
2. m mmm ME ees 1228 d BF458 sei R2061 D2024 4 5V 1N4149 E drai R2109 m22 R2063 ERB 3 1K 106 1 1 aner on 184149 bg 0 1 To R410 gt R2062 D2025 2K21 5V 1 21 2044 C2045 BC550C 1N4149 10p 5 1229 C406 Wo 82458 sel x IH 4 A 85 1001 1 KN 467v R215 d C409 D 3 391 9 R411 _ 0 9 Wired To CRT PCB 2 2 1 R2113 X Mag 73 x10 E Re ME C DIM M j DI 052112 R412 R413 1 4 221 245 51 1 u 220325 Ba 12V Vt 102008 p m P 10 T 0 16 C2056 H 02047 0 1 250 0 1 100V rA Gees Ge 2Vpp Tol 1 0 24 140V 880319 pp 2 2 eee s GEN emm 5 vam emm eee 0 TR Ad Le TR PCB ae TRC Trace Rotation Coil pos EE es de tee Sg ee 1 E IL Boord 1 A ES IL Option L R81 t izv we el Xx Ca TRZPCB Sen 1 All are types HAMEG Q 02 1 SCH electrolytic are 35V types Oscilloscope Dotum s NOSE Alle 1OpF Elkos aben 35V 12 Date 19 03 9 CT CT Socket HM 604 ss von Sest of
3. aaa a d Alle O 1uF haben 50 HM 60 4 All electrolytic are 35V types Trig TV Sep Alte 10uF Elkos hoben 35V Date Mhsn 29 06 1988 J Waldschmitt Blatt von Sheet of Pelqns usyeyaqion ueBuniepuy 709 8801 Sd DELAY LINE COMPONENT TESTER 4 8V 4 BV 2 1MHz BEER 8 au pennen mm Rea wm 12 CN2 8 A AY CH MPS3640 sel Y Se gt 12V CT GND L9V 1253 Soa i N 10 _ gt Line Trig To 9 1N4149 02034 1232 R2152 R2153 dM S9d A 2 To X Final Amp o gt 12V 12V CN2 8 1 E 12V ANI j a 2 779 12 Fr TB PCB P GND 2 hi 62164 NS 274 5 12 TR PCB R2165 7774 8 9 12V 15 144149 4V Tero 8 68p ES 454 000044242222 9 ALT Pulse Loun e 9 typ i 0 3V gt ra 1 gt CHB 19122 i i i i Km I 2 gt CN1 2 1 C O Ka 2 E 5 R2241 CN 2 2 gt sel STROBE Geng Kr To 05 Option D2051 T245 ics D N 8 x All cap are SOV types a ic 8 Alle Kond haben SOV All 10uF
4. m 10y CQY74 5 a C502 C505 0503 5 i 0502 I Unten Bottom CNS L d Oscilloscope Gergen Ba en em um emm em em em 2 5 1 nderungen vorbehalten Subject to change without notice ee ee ee ae Date Mhsn 30 06 1988 HM 604 Tea Sheet of eBueuo 0 ywalqns uayeysqioa usHunuepuy 109 8801 Bezeichnung der Bauteile Die elektrischen Bauteile sind so gekennzeichnet da die erste Nummer mit der Baugruppen Nummer bereinstimmt Chassis Y Eingang ext Triggereingang Ger testecker Netschalter Netztransformator usw EY Board I H Eingangsteiler Y Vorverst rker Kanal II X Y Board Y Zwischenverst rker Kanalumschaltungs Flip Flop Dioden Schaltlogik Chopper Generator Triggerverstarker Niederspannungsversorgung Testleiste X Endverst rker Component Tester TB Board Triggerschaltung Zeitbasis passiv Ablenkverz gerung Hold off Schaltung Helltastung TV Sync Sep Y Out Verst rker Calibrator Board YF Board Y Endverst rker Overscan Bereichs berschreitung Option Z Board Beschaltung der Kasthodenstrahlr hre R cklaufaustastung Hochspannungs Netzteil CO Board Potentiometer f r horizontale Strahllage Power LED DEL u TRIG LED Potentiometer f r Hold off TR Board Potentiometer f r Strahldrehung Spule f r Strahldrehung Raster Beleuchtungsschalter Opt
5. 4 4 Faf Figure 1 Amplitude and frequency spectrum for AM display 50 The display of the amplitude modulated HF oscillation can be evaluated with the oscilloscope provided the frequency spectrum is inside the oscilloscope bandwidth The time base is set so that several cycles of the modulation fre quency are visible Strictly speaking triggering should be ex ternal with modulation frequency from the AF generator or a demodulator However internal triggering is frequently pos sible with normal triggering using a suitable LEVEL setting and possibly also using the time variable adjustment Subject to change without notice Figure 2 Amplitude modulated oscillation F 1 MHz f 1 kHz 50 Ur 28 3 MV ims Oscilloscope setting for a signal according to figure 2 Depress no buttons Y CH I 20mV div AC TIM E DIV 0 2 ms div Triggering NORMAL with LEVEL setting internal or external triggering H the two values aand bare read from the screen the mod ulation factor is calculated from m SD a b s resp m SCR 100 where Ur Im and b 1 The variable controls for amplitude and time can be set ar bitrarily in the modulation factor measurement Their posi tion does not influence the result Triggering and Timebase With the LEVEL knob in locked position turned ccw to AT position automatic triggering a baseline is displayed con tinuously even
6. Pom C ue A e C mW iw en a UC PORE SI See 4 D 4 gt LES Saa UT NEZ EN T ee e Na TR vor 4 We PE a 4 pU TT T9 1d es IS MEME Ge Fi EI i ed s 2 Y 4 a ue 3 e id a g F 3 4 9 X K Em 4 Kuren m m E AA u Y fr G e D AUS DIG amp E E A e ES gt E a D P K m 4 d Po E D D E 4 _ 4 4 Cds D PE i 4 U P d F D x d D A a Kei D S D D un h i VM LI E C LR x P pom gt 900 d f deg J a fe 32elqng uayeyaqoa 709 8801 ed OFF Search Delay TV TV DEL Trg Moce HELL LPost Trig 5V I e DEL Trig TME Sel DEL Trig Vor 10 1 e 79 DEL Trig IN e From PTFS PCB 9 5 CO PCB e DEL LED 79 M SRB s 12V 2 10u amp T 9 ALT Puise R3283 12V 7 i m N 7l 9 SLOPE S Er D I 5 124 TV DEL Trig 6 12V IV DEL Trigt 9 T 4 2 EX ZUP n 0 2V R3338 x 1358 Nm Jecss
7. e MER ES Se VEA D ra D he d nes er am EN Sp AUN ii epee gr d JR 1 av d e d ee ER g SM 4 Ej TE wi E Wo 4 2E _ 4 5 4 e 4 See T gt u wi Qu 4 E gt 46 i HC QAM 1 LS A 4 3 P iD D E e m6 H gt e hx E A san 2 inn EY S bu rE 4 Dodd B 744 T TC AA on ung i am x BER ET e D D D 4 i 1 te a unt 4 G et PS e gt 4 L4 HOHER Si D BEC A 3 E M 5 m B rn T uv FN v DES i 4 2 m Ni H 1 e D du x 1 4 i 4 HI v i E d X GE GN be We A 4 CE D 2 4 t E E d gt s i e EHER 3 E e et 4 ames 2 m DD Ci i eyes a P E EST CSI eS C 4 ME MN gt n gt Co KA FL E D d S D yc t ER 3 Wl 5 oe 4 gt gt 1 s i NW A C3 3 4 4 E 3 oa A a d 1 a E P E 3 a 8 4 E s D E E rid m E Wi P 1 0 5 Set 346 ee mr Ta Cite er en e PE x gt f D E gt D B i i f r Uy E Hi D ad D gt 2
8. hole A plastic guide with slotted bottom is located behind the hole Pull and push the variable control MAG x5 and ad just balance pot so that the baseline no longer moves up or down When the trace remains steady correction of is completed Depress CH I II TRIG button Repeat adjustment procedure for CH I M7 604 Use and Compensation of Probes To display an undistorted waveform on an oscilloscope the probe must be matched to the individual input impedance of the vertical amplifier The HM604 s built in calibration generator provides squarewave signal with a very low risetime 5ns and switch selectable frequencies of approx 1 2 and 1 MHz at two output sockets below the CRT screen One output provides 0 2V 1 for 10 1 probes and 2V 1 are present at the other for 100 1 probes When the attenuator switches are set to 5mV cm vertical deflection coefficient these calibration voltages corre spond to a screen amplitude of 4 The output sockets have an internal diameter of 4 9mm to accommodate the internationally accepted shielding tube diameter of modern Modular Probes and F series slimline probes Only this type of construction ensures the extremely short ground connections which are essential for an undistorted waveform reproduction of non sinusoidal high frequency signals Adjustment at 1 kHz The C trimmer adjustment compensates the capacitive loading on the oscillos
9. w2 3 2 w2 3 2 w2 3 2 e EEE mmm EEE wem mmm GEN ees s 1 eet ee 4 8 mg mmm mmm s IE umm P 8 et Oe 71 Win w2 3 GND 2 D 1p w2 3 Y 0UT TX Te OV B 1 BC550C SKE Das 5 1 500 H E i T 1N4149 To From X Y Switch Ampittudens ma Senn Divt20 bag 412V XY 412V XY 5V 12V W3 B3 12 12 TV DEL Trig 412V TV 0FF 12V TV DEL Trg 412V IV ON 5 ER 12V BY2 W3 B3 1 W3 B3 2 w3 83 2 W3 B3 2 W3 B3 2 W3 B3 1 w3 83 1 W3 B3 2 6 0 0 4 aa o a o 6 6 m R3175 m ERB Spang 194149 R3169 R3170 LJ C3053 0 1 0 1 o 5 am Ze Cl N334 Zug BC550C AA gl 43174 j IS 2 5V EE rug er 1n 23 R31 Ipsos C3095 d E wo _ M HAMMER 5 Oscilloscope 5 R3121 m T R3122 E 2 5Vp p 1MHz 1N4149 144149 ___ E HM 604 Date Mhsn 05 09 1988 Blatt von Sheet of J Waldschmitt nderungen vorbehalten Subject to change without notice 709 8801 19 aonou alqns ueBuniepuy Best ckungsplan XY Board 2 HM604 EEN I do gt T
10. button the start of the sweep changes from the positive going to the negative going edge of the trigger signal Internally the HM 604 should trigger perfectly with sinosoi dal signals up to 100MHz at a display height of approx 5mm when the HF trigger coupling mode is set For external triggering EXT button depressed the EXT TRIG input connector requires a signal voltage of at least 20MV which is in synchronism with the Y input signal Checking of TV triggering is possible with a video signal of switchable polarity A check of both polarities in V and H mode should be made The display should not shift horizontally during a change of the trigger coupling from AC to DC with a sine wave signal without DC offset The basic requirement for this is a cor rect DC Balance Adjustment on the input of the vertical amplifier see Operating Instructions page M7 In the dual channel mode DUAL button depressed with alternate channel switching and with alternate trigger ing ALT button in the X Section depressed two non fre quency related signals e g mains line frequency signal and calibrator signal should reliably be triggered internally dependent on the positions of the CHI II TRIG I II pushbuttons In the dual channel mode with chop channel switching and depressed ALT button only triggering from Channel I should be possible Periodical signal blanks due to the chopper frequency 0 5 MHz should not be visible If both v
11. of the display must occur If pumping does occur it is normally due to a fault in the regu lation circuitry for the high voltage supply The presetting pots for the high voltage circuit minimum and maximum intensity are only accessible inside the instrument see Adjusting Plan and Service Instructions A certain out of focus condition in the edge zone of the screen must be accepted It is limited by standards of the CRT manufacturer The same is valid for tolerances of the orthogonality the undeflected spot position the non linear ity and the raster distortion in the marginal zone of the screen in accordance with international standards see CRT data book These limit values are strictly supervised by HAMEG The selection of a cathode ray tube without any tolerances is practically impossible Subject to change without notice Astigmatism Check Check whether the horizontal and vertical sharpness of the display are equal This is best seen by displaying a square wave signal with the repetition rate of approximately 1 MHz Focus the horizontal tops of the square wave signal at normal intensity then check the sharpness of the vertical edges If it is possible to improve this vertical sharpness by turning the FOCUS control then an adjustment of the astig matism control is necessary A potentiometer of 50 kQ see Adjusting Plan is provided inside the instrument for the cor rection of astigmatism see Service Instructions A certa
12. 880319 Anderungen vorbeholten Subject to change without notice Best ckungsplan HM 604 Component Locations CO Board 7 EYBoard 1 Z Board 7 HM 604 05 01 BOTTOM 0502 0503 Mhsn 8803523 01 _ 018 10 88 604 nderungen vorbehalten Subject to change without notice Lelong suayeysequon uebuniepuy 709 8801 14 2010 R2011 140V Alle O 1yF haben 50V Lee SE O 1pF Cap are 50V types C2001 83 5V TROO gt ve e go m bk OV w2 3 1 n 02011 EC Therm fuse 4 71 100V 1N4002 ah 7 120 C Rep CN2 6 1 To Z PCB CN2 6 1 1 To w2 5 1 rd Em To Z PCB CN2 6 1 1 To TB PCB CT ILLUM LINE Trig w2 3 1 7 a Ze TB PCB pio nis GE eee R2023 2 12 T210 12V Von Ni eue 0 8 Lu 8 To YF PCB 182024 w2 5 1 To C2016 CN1 2 1 To EY PCB Il 5 R2032 CN1 2 2 5K11 3 nn 9 274 Me ee Gre CN1 2 1 6 To I CN1 2 2 2 udis 22u 16V A w2 5 1 1 T E C2028 St GND aga R2046 R2047 5 ug power 5001 5 w2 5 1 _ w2 5 1 B To w2 5 1 5 TB PCB geit w2 3 1 s notes 7 w2 5 1 a 7 Power Plug ALOO1 b 2 Ta TB PCB Kaltgerdtestecker z eu w2 3 1 a To Z PCB 6 ACHT
13. Total value of input voltage So The dotted line shows a voltage alternating at zero volt level When superim posed a DC level the addition of the positive peak and the DC voltage results in the max voltage DC AC M4 604 It is very important that the oscilloscope input coupling is set to DC if an attenuator probe is used for voltages higher than 400V see page M6 Connection of Test Signal Time Measurements As a rule all signals to be displayed are periodically repeat ing processes and can also be designated as periods The number of periods per second is the recurrence frequency or repetition rate One or more signal periods or even part of a period may be shown as a function of the adjustment of the TIME DIV switch The time coefficients on the TIME DIV switch are indicated in ms cm and us cm Ac cordingly the dial is subdivided into three sectors The du ration of a signal period or a portion of the waveform Is ascertained by multiplying the relevant time horizon tal distance in cm by the time coefficient selected on the TIME DIV switch The time variable control small knob on the TIME DIV switch must be in its calibrated detent CAL for accurate measurement arrow horizontal and pointing to the right With the designations L displayed wave length in cm of one period T time in seconds for one period F recurrence frequency in Hz of the signal T time coefficient in o
14. In DEL TRIG mode and SEP switch in H or V position after delay triggering to the next following line is possible Therefore discrete lines are representable The slope is ap pointed by the TV or N position of the delay switch When not in TV trig mode the susceptibility to interference sense can be influenced 4 normal reduced Operation of the sweep delay is relatively easy as normally only 3 controls in the X Section need to be used the DELAY operating mode lever switch OFF SEARCH DELAY DEL TRIG the DELAY rotary switch delay time range and its variable control VAR 10 1 small knob on the DELAY switch The latter a twenty turn precision potentiometer with overwind protection can increase the delay time range tenfold An LED near the DELAY mode switch indicates the operating mode For reliable operation of the sweep delay it is recom mended that the following procedure should always be adopted also reference to the accompanying figures will be of assistance Figure 1 CTT Ti hi al te ql SRE MODE NORM TIME DIV 0 5 ms cm LED off Initially the sweep delay mode lever switch should be set in the OFF position In this mode the complete waveform under investigation will be displayed as for normal oscillo scope operation The mode indicator LED is not illuminated in OFF mode The time coefficient on the TIME DIV switch is selected so that 7 to 3 basic per
15. developed automatic After Delay Trigger mode to ensure extremely stable displays and jitter free measurements of asynchronous signal sections and bursts or pulse trains independent of amplitude fluctuations An active TV Sync Separator further enhances trigger quality of video frame and line sig nals In the alternate trigger mode two signals of different frequencies can be compared With this state of the art oscilloscope HAMEG again sets a new price performance standard which is not likely to be met by others in this category Users will be particularly impressed by the instrument s outstanding versatility and ease of operation These features are possible in the HM604 due to 5 meticulous attention to detail and many decades of successful design experience sories supplied ME 10 1 probes Line cord Operators Manual oat E VEIT TE TEE TREE DCN TQUE EE SCRI QUITE Ke ram PUPA OS Eae EC Hr E AC o SE Reg E AB ALS RU ERU EE Ut E Modular Probes The clear advantage over ordinary probes are field replaceable parts and the HF compensation feature on the 10 1 attenuator pro bes For the first time probes in this price range allow adjustments of their HF characteristics to match individually the input imped ance of each scope This is particularly important for scopes with higher bandwidths gt 50MHz as otherwise strong overshoot or rounding may occur when measuring fast rising square wav
16. ment dangerous Intentional interruption of the protec tive earth connection is prohibited The mains line plug should be inserted before connections are made to measuring circuits The grounded accessible metal parts case sockets jacks and the mains line supply contacts line neutral of the in strument have been tested against insulation breakdown with 2000 Vr m s 50Hz Under certain conditions 50 Hz or 60Hz hum voltages can occur in the measuring circuit due to the interconnection with other mains line powered equipment or instruments This can be avoided by using an isolation transformer Safety Class Il between the mains line outlet and the power plug of the instrument When displaying waveforms where the low level side of the signal is at a high poten tial even with the use of a protective isolation transformer it should be noted that this potential is connected to the os cilloscope s case and other accessible metal parts High voltages are dangerous In this case special safety precau tions are to be taken which must be supervised by qualified personnel if the voltage is higher than 42V Most cathode ray tubes develop X rays However the dose equivalent rate falls far below the maximum per missible value of 36pA kg 0 5 mR h Whenever it is likely that protection has been impaired the instrument shall be made inoperative and be secured against any unintended operation The protection is li kely to be im
17. 100 MHz LED indication for trigger action Slope positive or negative Sources Ch I Ch Il line external Coupling AC 10Hz to approx 20 MHz DC LF DC lt 50 2 HF 50 kHz 100MHZ Threshold external 50mvV Active TV Sync Separator for line and frame Slope positive or negative 2nd Triggering Del Trig autom or slope con trolled independent from slope direction selection for TV mode Threshold 1 div typicalO 5div Trigger bandwidth 225 Hz to 60 MHz Horizontal Deflection Time coefficients 23 calibrated steps from 50ns div to 1 s div in 2 5 sequence variable 2 5 1 to min 2 5s div accuracy in calibrated position 3 with X Magnifier x10 5 to 5 ns div Hold Off time variable 25 1 Delay 7 decade steps from 1 00 5 to 0 1 s variable approx 10 1 to 1 s Bandwidth X Amplifier DC 5bMHz 34dB Input X Amplifier via Channel sensitivity see Ch Il specification X Y phase shift lt 3 below 120 kHz Ramp output approx 5V positive going Component Tester Test voltage max 8 5 V4 open circuit Test current max 8MA shorted Test frequency 50 60 Hz line frequency General Information Cathode ray tube 150CTB31P 43 123 rectangular screen internal graticule 8x10 cm Total acceleration voltage 12 kV Trace rotation adjustable on front panel Calibrator square wave generator switchable from 1 kHz to 1 MHz t approx Output vo
18. A vertical ellipse indicates a small impedance or a rela tively large capacitance relatively small induct ance A sloping ellipse means that the component has a con siderable ohmic resistance in addition to its reactance The values of capacitance of normal or electrolytic capacitors from 0 1uFto1000uF be displayed and ap proximate values obtained More precise measurement can be obtained in a smaller range by comparing the Capacitor under test with a capacitor of known value Induc tive components coils transformers can also be tested The determination of the value of inductance needs some experience because inductors have usually a higher ohmic series resistance However the impedance value at 50 or 60 Hz of an inductor in the range from 20 S2 to 4 7 kQ can easily be obtained or compared Testing Semiconductors Most semiconductor devices such as diodes Z diodes transistors FETs can be tested The test pattern displays vary according to the component type as shown in the fi gures below The main characteristic displayed during semiconductor testing is the voltage dependent knee caused by the junc tion changing from the conducting state to the non conduct ing state It should be noted that both the forward and the reverse characteristic are displayed simultaneously This is always a two terminal test therefore testing of transistor amplification is not possible but testing of a single junction is easily
19. Two identical probes should be used for both vertical inputs Using a separate ground con nection and notconnecting the probe or cable shields to the circuit under test avoid ground loops hum common mode disturbances X Y Operation For X Yoperation the pushbutton in the X Section marked X Y must be depressed The X signal is then derived from the Channel II HOR INP The calibration of the X signal during X Y operation is determined by the setting of the Channel II input attenuator and variable control This means that the sensitivity ranges and input imped ances are identical for both the X and Y axes However the Y POS II control is disconnected in this mode Its function is taken over by the X POS control It is important to note that the X MAG x10 facility normally used for expanding the sweep should not be operated in the X Y mode It should also be noted that the bandwidth of the X amplifier is approximately 5 MHz 3dB and therefore an increase in phase difference between both axes is noticeable from 50 kHz upwards The Y Input signal may be inverted by using the INVERT channel 1 facility X Y Phase Measurements The X Y phase measurement method can be used to meas ure the phase difference between two signals of the same frequency This provides a method of measurement for sig MIO 604 nal frequencies up to 120 kHz However above this fre quency the inherent phase difference between the vertical and horiz
20. and quickly possible Since the CT test voltage applied is only very low 8 5V ms all sections of most semiconductors can be tested without damage However checking the breakdown or reverse voltage of high voltage semiconductors is not possible More important is testing components for open or short circuit which from experi ence is most frequently needed Testing Diodes Diodes normally show at least their knee in the forward characteristic This is not valid for some high voltage diode types because they contain a series connection of several MI6 604 diodes Possibly only a small portion of the knee is visible Z diodes always show their forward knee and up to approx 1 OV their Z breakdown forms a second knee in the oppo site direction A Z breakdown voltage of more than 12V can not be displayed m Seck Type Normal Diode High Voltage Diode Z Diode 12 V Terminals Cathode Anode Cathode Anode Cathode Anode Connections CT GD CT GD CT GD The polarity of an unknown diode can be identified by com parison with a known diode Testing Transistors Three different tests can be made to transistors base emit ter base collector and emitter collector The resulting test patterns are shown below The basic equivalent circuit of a transistor is a Z diode be tween base and emitter and a normal diode with reverse po larity between base and collector in series connection There are three different test patt
21. certain amount of protection for the input of the os cilloscope amplifier It should be noted that all attenuator probes must be compensated in conjunction with the oscil loscope see Probe Adjustment page 8 If a x IO or x 100 attenuator probe is used at voltages higher than 400 V the DC input coupling must always be set With AC coupling the attenuation is frequency de pendent the pulses displayed can exhibit ramp off DC volt age contents are suppressed but loads the respective input coupling capacitor of the oscilloscope The electric strength of which is maximum 400V DC peak AC For the suppression of unwanted DC voltages a capacitor of adequate capacitance and electric strength may be con nected before the input tip of the probe e g for ripple measurements It is important to remember that when low voltage signals are being investigated the position of the ground point on the test circuit can be critical This ground point should al ways be located as close as possible to the measuring point If this is not done serious signal deformation may M6 604 result from any spurious currents through the ground leads or test chassis parts This comment also applies to the ground leads on attenuator probes which ideally should be as short and as thick as possible For connection of a probe to a BNC socket a BNC adapter should be used It forms often a part of the probe accessory Grounding and match ing problems are
22. edge SLOPE button is in out position Triggering from negative going signal edge SLOPE button depressed This facility is important when only a portion of a cycle is being displayed Internal triggering select Channel with button CH UI TR UI Internal alternate triggering ALT button is depressed only with alternate channel switching External triggering from TRIG INP connector EXT button depressed External trigger signal 50 mV 0 5V time related to vertical input signal Line triggering TRIG selector switch in position Trigger coupling selected with TRIG switch AC DC LF HF Trig freq range AC and DC to 20 MHz HF above 20 MHz LF below 50 kHz Video signals with line freq TV SEP switch to H or H Video signals with frame freq TV SEP switch to V or V First or second half of frame selection with FIELDI II switch Pay attention to TRIG indication LED Measuring Sweep Connect test signal to and or CH II vertical input connector Compensate attenuator probe using CAL square wave signal Select AC or DC input coupling GD Y amplifier is disconnected from input and grounded Adjust required display height of signal with attenuator switch and variable control Select sweep speed with TIME DIV switch and variable control Adjust trigger point with LEVEL control Calibrated amplitude measurement with attenuator variable control to CAL Calibrated time measurement with TIME DIV variable control t
23. equal and about five divisions in amplitude Set the TIME DIV switch to a sweep rate which displays about one cycle of the waveform Move the waveforms to the center of the graticule with the Y POS I and Y POS II controls Turn the Variable Time Control until one cycle of the refer ence signal occupies exactly 10 divisions see next figure Each division represents 36 of the cycle Subject to change without notice Dual Trace Phase Difference Measurements T Horizontal distance forone period cm t Horizontal distance of zero crossing points cm Assume a horizontal difference of 3 divisions t 3cm and a period of 10 divisions T 21 the phase difference can be calculated using the following formula t 3 360 360 108 or 10 t arc 2 2 1 885rad Bob 10 7 respectively Measurement of an amplitude modulation The momentary amplitude u at time t of a HF carrier volt age which is amplitude modulated without distortion by a sinusoidal AF voltage is in accordance with the equation Ur sinQt 05m Uj cos Q o t 0 5m Ur cos Q o t where U unmodulated carrier amplitude Q 2 angular carrier frequency o 2 modulation angular frequency m modulation factor 1 2 100 The lower side frequency F fand the upper side frequency F f arise because of the modulation apart from the carrier frequency F Ur 0 5 0 5m
24. plug of the instrument has to be turned Triggering of video signals The built in active TV Sync Separator separates the sync pulses from the video signal permitting the display of dis torted video signals either in line H horizontal or in frame V vertical trigger mode The TV lever switch has five po sitions the OFF position is for normal operation The TV H and H positions horizontal line and the TV V and V vertical frame positions are used for video triggering In these four positions the TRIG coupling switch and the LEVEL control in NORM trigger mode are inoperative In the TV V and V positions frame trigger ing a low pass filter or integrating network is connected into circuit which forms a trigger pulse sequence with frame frequency from thevertical sync pulses incl pre and postequalizing pulses When in V mode it is possible to select field or Il by releas ing or depressing FIELD pushbutton For correct video triggering the and positions at V and H must be selected corresponding to the video input signal If the sync pulses are placed above the picture content H or V should be in use For sync pulses below the picture content of the input signal correct triggering without any influence from changing picture contents will be possible only in V or H setting The INVERT pushbutton only changes the display on the CRT not the input signal In TV H trigger mode the
25. respec tive channel in use In the Dualchannelmode the internal trigger signal may be selected from either Channel I or Channel using the button in the out po sition the trigger signal is derived from Channel However it is always preferable to trigger from the less complicated signal With internal alternate triggering ALT pushbutton in the X Section depressed in the DUAL channel alternate mode of the Y amplifier the trigger voltage is derived alternately from Channel I and Channel This trigger mode is par ticularly useful when two asynchronous signals are being investigated Normal triggering should be preferable in this mode The display of one signal only is not possible on the alternate trigger mode For external triggering the EXT pushbutton in the X Sec tion must be depressed The sync signal 0 05 V 0 5 Vpp must then be fed to the TRIG INP input socket Coupling mode and frequency range of the trigger signal are selected with the TRIG lever switch in the X Section for internal and external triggering provided that the TV SEP switch is in off position The HM 604 has 4 coupling modes AC DC LF HF The AC coupling mode is mainly used DC trigger coupling is only recommended when very low fre quency signals are being investigated and triggering at a particular value is necessary or when pulses which sig nificantly change in duty cycle during observation time have to be di
26. using 2 banana jacks Test leads supplied Component Tester Examples of Test Displays Short circuit Junction E C Z Diode 8V Z1 Capacitor Zut Operating Instructions General Information This oscilloscope is easy to operate The logical arrange ment of the controls allows anyone to become familiar with the operation of the instrument after a short time however experienced users are also advised to read through these instructions so that all functions are understood Immediately after unpacking the instrument should be checked for mechanical damage and loose parts in the in terior If there is transport damage the supplier must be in formed immediately The instrument must then not be put into operation Check that the instrument is set to the correct mains line voltage If not refer to instructions on page M2 Use of tilt handle To view the screen from the best angle there are three dif ferent positions C D E for setting up the instrument If the instrument is set down on the floor after being carried the handle remains automatically in the upright carrying posi tion A In order to place the instrument onto a horizontal surface the handle should be turned to the upper side of the oscillo scope C For the D position 10 inclination the handle should be turned in the opposite direction out of the carry ing position until it locks in place automatically underneath the instrument For the E pos
27. 9 BF423 MPS3640 TO 18 2N3866 39 2N2369A TO 18 Beispiel Kabelverbindung 2 3 1 5 bzw W2 3 1 52 61 62151 Flachkabelstecker auf Board W Flachkabelverbindung eine Seite verl tet andere Seite Buchsenleiste 2 3 Verbindung zwischen Board 2 und Board 3 1 1 Flachkabelverbindung zwischen Board 2 und 3 Draht Nummer des Flachkabels Example cable connection P2 3 1 5 or W2 3 1 5 respectively P Flat cable plug soldered on board W Flat cable wiring direct soldered on board with socket movable 2 3 Connection between Board 2 and Board 3 1 First flat cable connection between Board 2 and 3 5 Serial number of the wire in the flat cable Widerstand Resistor identification Widerstand Resistor 0 6W 1 2 carbon film 4 Widerstand Resistor 0 25 W 0 596 T 50 10 8 K metal film 709 8801 80 12elgns ueyeueqio 12V 12V TV OFF 12V TV ON 12V TV ON 12 12V TV OFF nderungen vorbehalten 1 Subject to change without notice EE 0 2V MEE Sy 1 4 TV Sap 1 AS DEES R3200 D 2 5 9 i 3 FSO DC Offset Ad 9 2ye Trig Out nz R3224 VR306 100y 16V a C3126 5V FDH300 BAS 33 d GND Time Base Board CON Oscilloscope All O 1uF cap ore 50
28. E paralleled by6808 Rectifier Thyristor G A together B E with 1 uF 68052 Si diode with 10 F MI8 604 Subject to change without notice Short Instruction for HM604 First Time Operation Connect the instrument to power outlet Switch on POWER pushbutton No other button is depressed LED indicates operating condition Case chassis and all measuring connectors are connected to the Safety Earth Conductor Safety Class I TRIG selector switch to AC TV SEP switch to OFF LEVEL knob in AT position Automatic Triggering DELAY lever switch to OFF and HOLD OFF control min Adjust INTENS control for average brightness Center trace on screen using X POS and Y POS I controls Then focus trace using FOCUS control Operating Modes of the Vertical System Trigger Channel I All pushbuttons in out position Channel Il CH UI TRIG I II button depressed Channel I and Channel Il DUAL button depressed Alternate channel switching ADD button in out position Chopped channel switching DUAL and ADD buttons depressed Signals lt 1kHz with CHOP Channel 1 Il sum ADD button depressed only Channel I Il difference ADD and INVERT CH buttons depressed Channel 1 II difference ADD and INVERT CH II buttons depressed Modes Automatic Triggering LEVEL knob in ATposition Trace always visible Normal Triggering LEVEL turnded cw Trace visible when triggered Triggering from positive going signal
29. EDs will indicate the position of the trace In X Y Operation X Y pushbutton depressed the sensitiv ity in both deflection directions will be the same When the signal from the built in square wave generator is applied to the input of Channel Il then as with Channel in the vertical direction there must be a horizontal deflection of 4 when the deflection coefficient is set to 50mV cm position T2 604 Subject to change without notice variable control set to its CAL position X MAG x10 released The check of the mono channel display with the CH button is unnecessary it is contained indirectly in the tests above stated Triggering Checks The internal trigger threshold is important as it determines the display height from which a signal will be stably dis played It should be approx 5mm for the HM 604 An increased trigger sensitivity creates the risk of response to the noise level in the trigger circuit especially when the sensitivity of the vertical input is increased by pulling the MAG x5 knob This can produce double triggering with two out of phase traces Alteration of the trigger threshold is only possible internally Checks can be made with any sine wave voltage between 50 Hz and 1 MHz The LEVEL knob should be in AT position Following this it should be ascertained whether the same trigger sensitivity is also pre sent with Normal Triggering LEVEL knob not in AT posi tion On depressing the SLOPE
30. INV 1 1 and XY Betrieb T 2 Triggering Checks T 3 Component Locations NICO Et 1323 ut A eee e cy a ee E XY Boards uu 5 u utes Be SSH D14 Sweep Delay T4 TE Board uo kom MARE OS 2 Dee D15 Component T 4 PIFS Board a Roue SR amp UR D16 Trace Alignment T 4 IT BG GAL YF Bards sa 252 E D17 Miscellaneous T4 OO EY 2 BOandS a aa e eee Ross D18 Subject to change without notice 9 88 604 Specification Vertical Deflection Operating modes Channel or Ch Il separate Channel and Il alternate or chopped Chopper frequency approx 0 5MHz Sum or difference of Ch and Ch Il with invert buttons for both Channels XY Mode via Channel and Channel Il Frequency range 2x DC to 60MHz Risetime approx 5 8ns Overshoot X196 Deflection coefficients 12 calibrated steps from 5 mV div to 20 V div in 1 7 5 sequence variable 2 5 1 to min 50V cm Accuracy in calibrated position 3 Y Magnification x5 calibrated to 1 mV div Frequency range DC to 20MHz input impedance 1 II 30pF Input coupling DC AC GD Ground Input voltage max 400V DC peak AC Y output from CH lor CH Il 50 MV div 50 Q Delay Line approx 90ns Trigger System With automatic 10Hz 100 MHz 25 mm height normal with level control from DC
31. T4 604 mally needs increasing with INTENS and FOCUS control However larger expansions than x200 are quite possible but the decrease of brightness and the jitter restricts the evalua tion When switching to DEL TRIG positions every slope is accepted for triggering after the delay time has elapsed In TVSEP mode condition the slope can be chosen Component Tester After pressing the COMPONENT TESTER button a horizon tal straight line has to appear immediately when the CT soc ket is open The length of this trace should be approx 8cm With connection of the CT socket to one of the ground jacks in the Y Section a vertical straight line with approx 6cm height should be displayed The above stated measurements have some tolerances They are dependent among other things on the mains line voltage Trace Alignment The CRT has an admissible angular deviation 5 between the X deflection plane DI D2 and the horizontal center line of the internal graticule This deviation due to tube producion tolerances and only important after changing the CRT and also the influence of the earth s magnetic field which is dependent on the instruments North orientation are cor rected by means of the TR potentiometer In general the trace rotation range is asymmetric It should be checked whether the baseline can be adjusted somewhat sloping to both sides round about the horizontal center line of the graticule With the HM 604 in it
32. Table of contents Technical Pl Accessories a x x xx SKK ERKENNEN ENGE Z 1 Operating Instructions General Information aoa a a aaa M 1 Use of tit handle M 1 hd an ENEE M 1 Operating conditions M2 Warranty oesi a a a M 2 Maintenance 2 2 64 o oom ee RO X V M 2 Mains Line voltage change M 2 of Signal sae met enm ood Ded M 3 Amplitude Measurements M 3 Time Measurements M 4 Connection of Test Signal 5 Operating 2 ww ob Sb ARS 6 i First Time Operation M 7 Os lo SCO pe Trace Rotation M 7 H M 604 DC Balance Adjustment M 7 Use and Compensation of Probes M 8 Operating Modes of the Y Amplifier M 9 KY Operation s e 0 Service Instructions X Y Phase Measurements MI 0 General ee ea ee ee ee ee S 1 Dual Trace Phase Difference Measurements 10 Instrument Case Removal S 1 Measurement of an amplitude modulation 1 Operating Voltages 51 Triggering Timebase 1 Minimum Brightness S 1 Triggering of video signals MI 2 Astigmatismus control S 1 Function of variable HOLD OFF control Trouble Shooting the Instrument 52 Sweep Delay After Delay T
33. UNG Dos Netzteil enth it sicherheitserhebliche Bouteille 1 Nur Origing Ersatzteile verwenden Rev gn ye Power Supply contains safety relevant ports Use original replacement parts only E CAUTION 9 Power Supp Netzsicherung 110V T 0 63A If opplicable Schutzklosse 1 Power fuse links 125V 5X20mm tr ge Oscilloscope 5X20mm time lag u 2 Datum Typ Leistung 41W bei 220V 50Hz mit Schutzleiter entf llt bel Schutzklasse 2 Type IEC 127 220V T Dum ME SB 9 01 1988 Typ power cons 41W ct 220V 50Hz ei m TREE m gege 240V 0 A T with safety earth conductor not In sofaty class 47 63Hz HM 6 CJ Bruder n 654 BS 4265 47 _440Hz Blatt von J Bruder Sheet of nderungen vorbehalten Subject to change without notice Best ckungsplan HM 604 Component Locations TBG Board CAL Board 4 aE Ge pet gees ER 4 ua 2 bd if ai E 8 e d at Xx lt 7 5 A8 1 H gt E Li wo D EX Ww Doe P E r r P 2 1 Cp Q 4 3 e e E d H d D P NLO e di 5 D 4 LS 3 Ji 2 k i 4 e Xw Some i ka Lat 3 e 4 2 4 S 5 a m 2 SE WW s S Aa Ge q Aq A ME Su F s 2 3 REOS A k A He UE eds D D D 92 mw 28 H
34. UPPLY HAMEG Oscilloscope HM 604 Datum Date Blatt Sheet BLOCKSCHALTBILD BLOCK DIAGRAM 150 CTB 31 Rev O1 Mhsn 12 09 1988 von J Bruder of J Waldschmitt 709 8801 90 1281415 Overscan Einheit optionell Overacan circult optional Alle haben SOV 1 All 0 1p cop are 50V types Alle 10u Elkos haben 35V All 19y electrolytic cop ore 35V types Entf llt mit 05 Delete with OS option Falis erforderlich durchgeschaltten Cut applicable CRT PCB I ur 10KHz ok 16 iv 1 5CA31271 iCS1 imo R5075 L4 R5j 2 Pu MPS918 1505 i 4 gt Lg 10164 BS e j P2 5 1 KH ES ber R5060 l i t 1 014 C501 C503 GRN 13 5V ot 20 P2 5 1 11 5V at 25 R5102 12V 6 HI TZIR Wan D505 R5032 R5033 eS ee GR DD es nA A wm a 1 x D504 i J 47K NTC sense P2 5 1 R5031 GND From a 1N4149 1N4149 i i D510 0511 1512 p2 5 1 R5002
35. ading edge T alters the lower frequencies HZ52 After completion of the HF adjustment the signal amplitude displayed on the CRT screen should have the same value as during the 1 kHz adjustment Probes other than those mentioned above normally have a larger tip diameter and may not fit into the calibrator out puts Whilst it is not difficult for an experienced operator to build a suitable adapter it should be pointed out that most of these probes have a slower risetime with the effect that the total bandwidth of scope together with probe may fall far below that of the HM604 Furthermore the HF adjust ment feature is nearly always missing so that waveform dis tortion can not be entirely excluded Adjustment 1 MHz Subject to change without notice The adjustment sequence must be followed in the order described i e first at 1 kHz then at 1MHz The calibrator frequencies should not be used for timebase calibrations The pulse duty cycle deviates from 1 1 ratio Prerequisites for precise and easy probe adjustments as well as checks of deflection coefficients are straight hori zontal pulse tops calibrated pulse amplitude and zero potential at the pulse base Frequency and duty cycle are relatively uncritical For interpretations of transient response fast pulse risetimes and low impedance generator outputs are of particular importance Providing these essential features as well as switch select able output frequencie
36. btained by increasing the timebase sweep speed from 0 5ms cm to 50us cm Also the pre cise measurement for the delayed portion of the waveform is possible In the example this was found to be 250us on multiplication of the horizontal length in cm of an optional signal section by the time coefficient just adjusted Figure 4 T MODE DELAY DELAY range 1ms TIME DIV 50 us cm LED illuminated Expansion 0 5 10 50 1078 10 T 5cm 50 250 us Operation of the sweep delay requires a constant trigger point All signals which have a constant phase shift be tween the expanded section and trigger point pose no problems This means all electrical signal shapes which contain signal edges of the same polarity and with trigger able level values which are constantly repeated with the re curring frequency If there is no constant phase shift the triggering may fail after switching from the SEARCH to DELAY position or with changing of the time coefficient It is best to attempt to find a trigger point which has a constant phase shift up to the signal section to be expanded in the OFF mode With complicated composite signals the display of the basic period could become superimposed by other signal por tions These dissappear as a rule when the sweep 1 in creased Otherwise a stable expanded display is obtained by adjusting the LEVEL and the variable sweep control or by means of the HOLD OFF control Using
37. calculated as 0 2 V 4cm 50mV cm Subject to change without notice tor Settings CH 1 attenuator switch to 50mV cm CH II attenuator switch to 0 1V cm CH 1 input coupling to DC input coupling to GD TIME DIV switch to 0 5ms cm automatic triggering LEVEL knob in AT position TRIG selector to AC no button depressed Now the square wave signal is visible with 4em display height With Y POS l control the tops of the square wave are adjusted to 2cm from the horizontal center Y POS IICH IkolL Tpentthe oupling is set to DC Now the signal across the Y output appears with the same phase position as the calibrator signal via Channel As well as the DC offset e g 0 8 2 4 80mV the amplitude e g 2cm 0 2V of the Y output can be measured In the example the sensivity of the Y output can be calculated as 0 2V 4cm 50mV cm Subject to change without notice Z modulation optional Checking the blanking facility on the 2 modulation connec tor rear panel is possible with a sine or square wave generator The sine wave generator requires an output volt age control The square wave generator must deliver posi tive pulses to ground chassis Alternatively a small adjust able sine voltage from a separate power transformer may be used For the latter set the TIME DIV range to e g 10ms cm With the TIMEBASE variable control the gap in the baseline can be brought acceptably to a standstill Line frequency tr
38. ch are symmetrically adjusted to the horizontal center line the internal graticule of the CRT has two horizontal dot ted lines 2 4cm from the center line Adjust the Y at tenuator switch with its variable control together with the Y POS control so that the pulse height is precisely aligned with the 0 and 100 lines The 10 and 90 points of the signal will now coincide with the two lines which have a distance of 2 4cm from the horizontal center line and an additional subdivision of 0 2cm The risetime is given by the product of the horizontal distance in cm between these two coincidence points and the time coefficient setting If magnification is used this product must be divided by 10 The fall time of a pulse can also be measured by using this method o mm LE AL TTTTELTTT EENE 10 The above figure shows correct positioning of the oscillo scope trace for accurate risetime measurement With a time coefficient of 0 05us cm and pushed X MAG x 10 button the example shown in the above figure results in a measured total risetime of tio 1 6cm 0 05us cm 10 8ns When very fast risetimes are being measured the rise times of the oscilloscope amplifier and the attenuator probe have to be deducted from the measured time value The risetime of the signal can be calculated using the following formula t V ta ts Ls In this
39. circuit Delay circuit Hold off circuit TV sync separator Y Out amplifier Calibrator Board YF Board Y Final amplifier overscan circuit optional Z Board CRT circuit Unblanking HV supply CO Board X pos pot Power LED DEL and TRIG LED Hold off pot TR Board Trace rotation pot Trace rotation coil illumination switch optional CRT Board CRT socket TBG Board Timebase generator active Timebase buffer amplifier PTFS Board After Delay trigger post trigger Field selector OS Board Option Overscan indicators LED s IL Board Option Graticule illumination NC Testleiste Check strip 68 XY Board NC NC NC 140V NC GND Nc 12V NC 5V 5V 12 ot O N U N A guo o 0 5 bk schwarz black bn braun brown rd rot red or orange orange BC550C BC560C BF414 Anschlu folge der Transistoren Terminals of Transistors Ansicht von unten Bottom view Ansicht von oben Top view TB Board 3 Stecker Plug Buchse Socket W2 3 1 X Y Board 2 Identification of electrical Components Farbkennzeichnung der Anschlu dr hte Color Abbreviations for insulated wire ye gelb yellow gr grau grey gn gr n green wh wei white bl blau blue trp transparent transparent i violett violet gn ye gr n gelb green yellow stripe BD651 TL431C BF422 MPS918 BF256B 1 BSX1
40. cope input approx 30pF with the HM604 By this adjustment the capacitive division assumes the same division ratio as the ohmic voltage divider to ensure an equal division ratio for high and low fre quencies as for DC For 1 1 probes or switchable probes set to 1 1 this adjustment is neither required nor possible A baseline exactly parallel to the horizontal graticule lines is a major condition for accurate probe adjustments See also Trace Rotation TR page M7 Connect the probes Types HZ51 52 53 54 or HZ37 to CH 1 input All pushbuttons should be released in the out position and all push pull Knobs pushed in Set the input coupling switch to DC the attenuator switch to 5mV cm and the TIME DIN switch to 0 2ms cm and all variable controls to CAL position Plug the probe tip into the appro priate calibrator output socket i e 10 1 probes into the 0 2V socket 100 1 probes into the 2 0V socket correct incorrect incorrect Approximately 2 complete waveform periods are displayed on the CRT screen Now the compensation trimmer has to be adjusted Normally this trimmer is located in the probe head On the 100 1 probe HZ53 however it is located in the connecting box at the other end of the cable Using a 8 604 small insulated non metallic screwdriver or trimming tool the trimmer has to be adjusted slowly until the tops of the squarewave signal are exactly parallel to the horizontal g
41. cy tolerance should not be greater than 1 The timebase accuracy of the HM 604 is given as 3 but as a rule it is considerably bet ter than this For the simultaneous checking of timebase linearity and accuracy at least 10 oscillations i e 7 cycle everycm should always be displayed For precise determi nation set the peak of the first marker or cycle peak exactly behind the first vertical graticule line using the X POS con trol Deviation tendencies can be noted after some of the marker or cycle peaks 20 and 10 ms cm ranges of the TIME DIV switch can be checked very precisely with line frequency 50 Hz only On the 20 ms cm range a cycle will be displayed every cm while on the 10 ms cm range it will be every 2cm The following table shows which frequencies are required for the particular ranges s cm 1 Hz 0 1 ms cm 10 kHz 0 5 s cm 2 Hz 50 cm 20 kHz 0 2 s cm 5 Hz 20 us cm 50 kHz 0 1 s cem 10 Hz 10 us cem 100 kHz 50 ms cm 20 Hz 5 us cm 200 kHz 20 ms cm 50 Hz 2 ysicm 500 kHz 10 ms cm 100 Hz us cm 1 MHz 5 ms icem 200 Hz 0 5 us cm 2MHz 2 ms em 500 Hz 0 2 usicem 5MHz 1 ms cm 1 kHz 0 1 gs cm 10MHz 0 bms cm 2 kHz 0 05 us cm 20MHz 0 2 ms icm 5 kHz 604 The time variable control range can also be checked The sweep speed becomes slower by turning this variable con trol counter clockwise to its left stop 2 5 cycles at least every c
42. e U 220Vims 2 V2 622 V voltage 160 V with probe X 10 U 62 2 desired display height H min 3 2cm max 8cm max deflection coefficient D 62 2 3 2 19 4V cm min deflection coefficient D 62 2 8 7 8V cm adjusted deflection coefficient D 10V cm If the applied signal is superimposed on a DC direct voltage level the total value DC peak value of the al ternating voltage of the signal across the Y input must not exceed 400V see figure This same limit applies to normal x 10 attenuator probes the attenuation ratio of which allows signal voltages up to approximately 1 000V to be evaluated Voltages of up to approximately 2 400 V may be measured by using the HZ53 high voltage probe which has an attenuation ratio of 100 1 It should be noted that its peak value is derated at higher frequencies If a nor mal x 10 probe is used to measure high voltages there is the risk that the compensation trimmer bridging the attenuator series resistor will break down causing damage to the input of the oscilloscope However if for example only the re sidual ripple of a high voltage is to be displayed on the oscil loscope a normal x 10 probe is sufficient In this case an ap propriate high voltage capacitor approx 22 68nF must be connected in series with the input tip of the probe Voltage DC AC peak 400 Dc DC E NAC P ilb S Ki Time N N
43. e sure that only fuses of the specified type are used for replacement 5 20 quick acting 250V C 50mA IEC 127 1 or DIN 41661 Test Pattern Displays Page M 18 shows typical test patterns displayed by the vari ous components under test Open circuit is indicated by a straight horizontal line Short circuit is Shown by a straight vertical line Testing Resistors If the test object has a linear ohmic resistance both deflect ing voltages are in the same phase The test pattern ex pected from a resistor is therefore a sloping straight line The angle of slope is determined by the resistance of the resistor under test With high values of resistance the slope will tend towards the horizontal axis and with low values the slope will move towards the vertical axis Values of resistance from 20 to 4 7kQ can be approxi mately evaluated The determination of actual values will come with experience or by direct comparison with a com ponent of a known value 604 Testing Capacitors and Inductors Capacitors and inductors cause a phase difference be tween current and voltage and therefore between the X and Y deflection giving an ellipse shaped display The posi tion and opening width of the ellipse will vary according to the impedance value at 50 or 60Hz of the component under test A horizontal ellipse indicates a high impedance or a re latively small capacitance or a relatively high induct ance
44. electrolytic cop 35 2 weg A L sop Er e Q D2057 Palete without O5 Option 9 i 1N4149 C2082 J Entf ilt ohne 05 0 16 E 1 4 4011 1 5V ALT Trig Rev CN1 2 2 4 24 1 4149 2 X Y Board 0 2 f 36 p _ z SCI oscope Datum 1N4154 sel A9 03 TRIGGER PRE AMPLIFIERS E bes el ee a tl Date Mhsn 19 03 1988 CN2 3 2 CN2 3 2 Th CN2 3 2 SE HM E 604 Bn P Duttin Anderungen vorbehalten Subject to change without notice Y BY iV 5 u CH 1 CH il Sheet of DEE 709 8801 o1 2 uaBuniepuy 12V Bci899 661 215 10 4 TH 9 HV CASCADE 2 C604 35V R612 MPS3640 iz 42V typ e 2v ZUP Freen TB Board 1604 MPS918 110 sel Dark H1 4V 4 8V R607 10n 2KV typ pod D604 0614 0 3V BAV 1 w2 6 1 R603 0601 Gy 5381 194149 606 C617 25V Bright C608 typ TE a7 N 10n 2KV Dork 16V R604 D603 R614 C637 Z MOD 5181 P 6615 1 100v To BNC Socket Z 1N4149 R605 Oscilloscope Zu 2 5K 30p 0616 Analog Ref 1 9V f 4 SMHz 68pH C615 REM 120 C618 19 w2 6 1 10n 2KV L10n 2KV 10n 2KV 023 10n 2KV a Gg ee oe eee eee eee e 35V 35 INTENS Ism ssv
45. eline For this the DELAY VAR 10 1 control must be set to xl rotate coun terclockwise until a snap noise is audible When DELAY mode is selected the trage reverts to the full 10cm display without any blanking Over the full range of adjustment of the DELAY VAR 10 1 control the displayed waveform of the calibration signal should be shifted without any jitter jumping or intermittent blanking Control settings Connect calibrator socket 0 2 V 1kHz to CH 1 input connector DC input coupling deflection coeffi cient 50mV cm TRIG selector switch to AC time coeffi cient 1 ms cm no pushbutton depressed all controls cali brated position DELAY mode switch in OFF position LEVEL knob in AT position Now the calibrator signal is displayed with a signal height of 4cm and approx 1 cycle per cm After switching to SEARCH the mode indication lamp blinks Set the DELAY range switch to 1 ms Rotate the DELAY VAR control until the left half of the display is blanked The delay time is now 51 After switching to DELAY the display is again fully visible The DELAY mode LED is illuminated con tinuously The displayed signal can now be expanded For this purpose turn the TIME DR switch clockwise to 5us cm The expansion is now x200 With the DELAY VAR con trol the nearest edge of the calibration signal can be brought in the screen center and checked on the above mentioned criteria With x200 expansion the display brightness nor
46. ements the variable con trol on the attenuator switch must be set to its calibra ted detent CAL When turning the variable control ccw the sensitivity will be decreased by a factor of 2 5 Therefore every intermediate value is possible within the 7 2 5 sequence With direct connection to the vertical input signals up to 400 V may be displayed attenuator set to 20 V cm vari able control ccw When pulling the variable control knob MAG x5 the sen sitivity is increased by a factor of 5 Hence follows a min de flection coefficient of 1 mV cm reduced bandwidth With the designations H display height in cm U signal voltage in Vy at the vertical input D deflection coefficient in V cm at attenuator switch the required quantity can be calculated from the two given quantities _U H U 5 D H M3 604 However these three values are not freely selectable They have to be within the following limits trigger threshold ac curacy of reading between 0 5 and 8cm if possible 3 2 to 8cm U between 1 MV and 160V D between 5mV cm and 20 V cm 1 2 5 sequence D between 1 mV cm and 4V cm in 2 5 sequence with pulled MAG x5 knob Examples Set deflection coefficient D 50 mV cm amp 0 05 V cm observed display height H 4 6 cm required voltage U 0 05 4 6 0 23 V Input voltage U 5V set deflection coefficient D 1 V cm required display height H 5 1 5 Signal voltag
47. ended for relatively low frequencies up to approx 50kHz For higher frequencies and when the signal source is of low impedance a cable of matched characteristic impedance usually 500 is recommended In addition and especially when investigating square or pulse waveforms a resistor equivalent to the characteristic impedance of the cable must also be connected to the cable directly at the input of the oscilloscope When using a 509 cable such as the HZ34 a 5092 through termination type HZ22 is available from HAMEG When investigating square or pulse waveforms with fast risetimes transient phenomena on both the edge and top of the signal may be come visible if the correct termination is not used It must be remembered that the BOQ through termination will only dissipate a maximum of 2 watts This power consumption is reached with 1 OV ms or with 28V sine signal If a x 10 or x 100 attenuator probe is used no termination is necessary In this case the connecting cable is matched di rectly to the high impedance input of the oscilloscope When using attenuator probes even high internal imped ance sources are only slightly loaded by approximately 10 MQ I 16 pF or 100 MQ I I7 pF respectively Therefore when the voltage loss due to the attenuation of the probe can be compensated by a higher sensitivity setting on the HM 604 the probe should always be used Also it should be remembered that the series impedance of the probe pro vides a
48. er or not components are faulty The CT can be used for quick checks of semiconductors e g diodes and transistors resistors capacitors and inductors Certain tests can also be made to integrated circuits All these components can be tested in and out of circuit The test principle is fascinatingly simple The power trans former of the oscilloscope delivers a sine voltage which is applied across the component under test and a built in fixed resistor The sine voltage across the test object is used for the horizontal deflection and the voltage drop across the re sistor i e current through test object is used for vertical de flection of the oscilloscope The test pattern shows a cur rent voltage characteristic of the test object Since this circuit operates with mains line frequency 50 or 60 Hz and a voltage of 8 5V max open circuit the indicat ing range of the CT is limited The impedance of the compo nent under test is limited to a range from 2022 to 4 7 kQ Below and above these values the test pattern shows only short circuit or open circuit For the interpretation of the dis played test pattern these limits should always be borne in mind However most electronic components can normally be tested without any restriction Using the Component Tester The CT is switched on by depressing the COMPONENT TESTER pushbutton This makes the vertical preamplifier Subject to change without notice and the timebase generator i
49. erns l N P N Transistor Terminals b e b c GC Connections CT GD CT GD CT GDI P N PTransistor 12 aoe BEER N 1 Terminals b e b c Connections CT GD CT GD CT GD For a transistor the figures b e and b c are important The fi gure e c can vary but a vertical line only shows short circuit condition These transistor test patterns are valid in most cases but there are exceptions to the rule e g Darlington FETs With the CT the distinction between a P N P to a N P N transis tor is discernible In case of doubt comparison with a known type is helpful It should be noted that the same socket connection CT or ground for the same terminal is then absolutely necessary A connection inversion effects a rotation of the test pattern by 180 degrees round about the center point of the scope graticule Subject to change without notice Pay attention to the usual caution with single MOS com ponents relating to static charge or frictional electricity In Circuit Tests Caution During in circuittests make sure the circuit is dead No power from mains line or battery and no signal inputs are permitted Remove all ground connections in cluding Safety Earth pull out power plug from outlet Remove all measuring cables including probes between oscilloscope and circuit under test Otherwise the con nection of both CT test leads is not recommended In circuit tests are possible in
50. ertical inputs are AC coupled to the same signal and both traces are brought to coincide exactly on the screen when working in the alternate dual channel mode then no change in display should be noticeable when the ALT button is depressed or released Subject to change without notice Checking of the line mains frequency triggering 50 60 Hz is possible when the input signal is time related multiple or submultiple to the power line frequency TRIG selector switch to LINE In this trigger mode there is no trigger threshold Even very small input signals are triggered stably e g ripple voltage For this check use an input of approx 1 V The displayed signal height can then be varied by turn ing the respective input attenuator switch and its variable control Timebase Before checking the timebase it should be ascertained that the trace length is 10cm If not it can be corrected with the potentiometer for sweep amplitude see Adjusting Plan This adjustment should be made with the TIME DIV switch in a mid position i e 5us em Prior to the com mencement of any check set the time variable control to CAL and the HOLD OFF time control to min The X MAG X10 button should be released This condition should be maintained until the variation ranges of these controls are checked If a precise marker signal is not available for checking the Timebase time coefficients then an accurate sine wave generator may be used Its frequen
51. es An exact HF compensation however is only possible with square wave generators having a risetime lt 5ns Most HAMEG scopes already feature such a calibration generator For other oscillo scopes it is available as accessory item HZ60 2 At present the following Modular Probes are available HZ36 without HF com pensation Type HZ36 HZ51 HZ52 HZ53 HZ54 selectable selectable Attenuation Ratio 1 1 10 1 10 1 10 1 100 1 1 1 10 1 Bandwidth min MHz 10 100 150 250 150 10 150 Risetime ns 3513 5 2 11 4 lt 2 35 lt 2 Inp Capacitance pF 47118 16 16 6 5 40 18 Inp Resistance MR 1 10 10 10 100 1 10 Inp Voltage max 600 600 600 1200 600 Cable Length m 1 5 1 2 1 5 1 5 1 2 Spare Cable for HZ36 HZ39 Spare Cable for HZ51 HZ54 HZ57 Sparepart Kit 2 sprung hooks 2 screw tips 1 ground cable HZ46 Demodulator Probe HZ55 Special probe for AM demodulation and wobbulator measure ments HF Bandwidth 100kHz 500MHz 19 AC Input Vott age 250mV 50Vims DC isolation Voltage 200V DC including peak AC Cable length 1 2m High Voltage Probe HZ58 For measurement of voltages up to 15kV Input resistance approx 500 m Recommended load resistance1 10 switchable Attenuation ratio 1000 1 Bandwidth 1 MHz Cable length 1 5 m BNC connector Printed in West Germany 5 90 Test Cable Banana BNC HZ32 Coaxial test cable length 1 15 m characteristic impedance 500 Cable capacitance 120pF Input voltage
52. es to be measured can therefore be determined relatively accu rately However from approximately 25 MHz upwards the measuring error will increase as a result of loss of gain At 40MHz this reduction is about 10 Thus approximately 11 should be added to the measured voltage at this fre quency As the bandwidth of the amplifiers differ normally between 65 and 70 MHz the measured values in the upper limit range cannot be defined exactly Additionally as al ready mentioned for frequencies above 60MHz the dynamic range of the display height steadily decreases The vertical amplifier is designed so that the transmission per formance is not affected by its own overshoot First Time Operation Check that the instrument is set to the correct mains line voltage Refer to page 2 Before applying power to the oscilloscope it is recom mended that the following simple procedures per formed Check that all pushbuttons in the out position i e re leased Rotate the three variable controls with arrows to their calibrated detent Set the variable controls with marker lines to their mid range position marker lines pointing vertically The LEVEL control knob should be on its left stop AT The three lever switches in the X Section should be set to their uppermost position Both input coupling slide switches for CH 1 and CH Il in the Y Section should be set to the GD position Switch on t
53. est plan of this manual can be performed without great expenditure on measuring instru ments However purchase of the new HAMEG scope test er HZ 60 which despite its low price is highly suitable for tasks of this type is very much recommended The exterior of the oscilloscope should be cleaned regularly with a dusting brush Dirt which is difficult to remove on the casing and handle the plastic and aluminium parts can be removed with a moistened cloth 99 water 1 96 mild detergent Spirit or washing benzine petroleum ether can be used to remove greasy dirt The screen may be cleaned with water or washing benzine but not with spirit alcohol or solvents it must then be wiped with a dry clean lint free cloth Under no circumstances may the cleaning fluid get into the instrument The use of other cleaning agents can attack the plastic and paint surfaces Switching over the mains line voltage The instrument is set for 220V 240V U K line voltage on delivery It can be switched over to other voltages at the fuse holder combined with the 3 pole appliance inlet at the rear of the instrument Firstly the fuse holder printed with the voltage values is removed using a small screw driver and if required provided with another fuse Refer to the table below for the prescribed value of the fuse Then replace the fuse holder so that the impressed white triangle points to the desired voltage Here pay attention that the cover plate is als
54. f the probe and the input of the oscilloscope Operating Modes of the Y Amplifier The required operating modes are selected on three pushbuttons located in the Y Section For Mono operation all pushbuttons should be in the out position the instru ment is then operating on Channel only 9 604 For Mono operation with Channel Hl the CH VII TRIG pushbutton has to be pressed When the DUAL button is depressed the HM604 is in Dualchannel operation In this mode the channels are displayed consecutively alternate mode This mode is not suitable for the display of very low frequency signals lt 1kHz as the tracewill appear to flicker or jump Under these conditions the ADD button should be depressed additionally selecting chopped mode In this position both channels then share the trace during each sweep period For the display of high frequency signals the type of channel switching selected is less important To select the add mode only the ADD button should be depressed The signals on both channels are then added together If in this mode one channel is inverted pushbut ton INVERT depressed then the difference between the two channels is displayed For both of these operating modes the vertical position of the trace depends on the set ting of the Y POS controls of both channels Differential measurements techniques allow direct meas urement of the voltage drop across floating components both ends above ground
55. he oscilloscope by depressing the red POWER pushbutton An LED will illuminate to indicate working order The trace displaying one baseline should be visible after short warm up period of 10 seconds Adjust Y POS l and X POS controls to center the baseline Adjust IN TENS intensity and FOCUS controls for medium bright ness and optimum sharpness of the trace The oscilloscope is now ready for use If only a spot appears CAUTION CRT phosphor can be damaged reduce the intensity immediately and check that the X Y pushbutton is in the released out position If the trace is not visible check the correct positions of all knobs and switches particularly LEVEL knob in AT position and DELAY MODE lever switch to OFF Subject to change without notice To obtain the maximum life from the cathode ray tube the minimum intensity setting necessary for the measurement in hand and the ambient light conditions should be used Particular care is required when a single spot is dis played as a very high intensity setting may cause damage to the fluorescent screen of the CRT Switching the oscillo scope off and on at short intervals stresses the cathode of the CRT and should therefore be avoided Trace Rotation TR In spite of Mumetal shielding of the CRT effects of the earth s magnetic field on the horizontal trace position cannot be completely avoided This is dependent upon the orientation of the oscilloscope on the place of work A cent
56. ied personnel As with the First Time Operation instructions care should be taken that all knobs with arrows are set to their calibrated positions None of the pushbuttons should be depressed LEVEL knob out in AT position TRIG selector switch to AC DELAY slide switch to OFF It is recommended to switch on the instrument for about 30 minutes prior to the commencement of any check Cathode Ray Tube Brightness and Focus Linearity Raster Distortions Normally the CRT of the HM 604 has very good brightness Any reduction of this brightness can only be judged visually However decreased brightness may be the result of reduced high voltage This is easily recognized by the greatly increased sensitivity of the vertical amplifier The control range for maximum and minimum brightness inten sity must be such that the beam just disappears before reaching the left hand stop of the INTENS control particu larly when the X Y button is depressed while with the con trol at the right hand stop the focus and the line width are just acceptable With maximum intensity the timebase fly back must onnoaccountbe visible Visible display fault without input signal Bright dot on the left side or decreasing bright ness from left to right or shortening of the baseline Cause incorrect Unblanking Pulse It should be noted that with wide variations in brightness refocusing is always necessary Moreover with maximum brightness no pumping
57. iggering is better TRIG selector switch to The length ratio from bright to dark lines on the display is dependent on the sine voltage amplitude Without a mod ulating generator the function of the Z modulation can be checked coarsely by short circuiting the Z connector Then the baseline is blanked fully T5 604 Service Instructions General The following instructions are intended as an aid for the electronic technician who is carrying out readjustments on the HM 604 if the nominal values do not meet the specifica tions These instructions primarily refer to those faults which were found after using the Test Instructions How ever this work should only be carried out by properly qual ified personnel For any further technical information call or write to HAMEG Addresses are provided at the back of the manual It is recommended to use only the original packing material should the instrument be shipped to HAMEG for service or repair see also Warranty page 2 Instrument Case Removal The rear cover can be taken off after unplugging the power cord s triple contact connector and after two cross reces sed pan head screws M4x30mm with two washers on it have been removed While the instrument case is firmly held the entire chassis with its front panel can withdrawn forward When the chassis is inserted into the case later on it should be noticed that the case has to fit under the flange of the front panel The same ap
58. in loss of marginal sharpness of the CRT is unavoidable this is due to the manufacturing process of the CRT Symmetry and Drift of the Vertical Amplifier Both of these characteristics are substantially determined by the input stages of the amplifiers The checking and correction of the DC balance for the amplifiers should be carried out as already described in the Operating Instructions page M 7 The symmetry of Channel and the vertical final amplifier can be checked by inverting Channel depress INVERT CH pushbutton The vertical position of the trace should not change by more than 5mm However a change of 1 cm is just permissible Larger deviations indicate that changes have occurred in the amplifier A further check of the vertical amplifier symmetry is possi ble by checking the control range of the Y POS controls A sine wave signal of 1 00 kHz is applied to the amplifier input When the Y POS control is then turned fully in both directions from stop to stop with a display height of approx imately 8 the upper and lower positions of the trace that are visible should be approximately of the same height Dif ferences of up to 1 cm are permissible input coupling should be set to AC Checking the drift is relatively simple Ten minutes after switching on the instrument set the baseline exactly on the horizontal center line of the graticule The beam position must not change by more than 5mm during the followi
59. ing plate volt ages of the CRT In almost any case the faulty section can be located The sections represent 1 Vertical deflection 2 Horizontal Deflection 3 CRT circuit 4 Power supply While the measurement takes place the position controls of both deflection devices must be in mid position When the deflection devices are operating properly the separate voltages of each plate pair are almost equal then Y 42V and X 67 V If the separate voltages of a plate pair are very different the associated circuit must be faulty An absent trace in spite of correct plate voltages means a fault in the CRT circuit Missing deflection plate voltages is probably caused by a defect in the power supply 52 604 Replacement of Components and Parts For the replacement of parts and components use only parts of the same or equivalent type Resistors without specific data in the diagrams have a power dissipation of 0 25 Watt and a tolerance of 2 96 Resistors in the high volt age circuit must have sufficient electric strength Capacitors without a voltage value must be rated for an operating voltage of 63V The capacitance tolerance should not exceed 20 Many semiconductors are selected especially the gate diodes 1 N4154 and all amplifier transis tors which are contained in push pull circuits including the FETs If a selected semiconductor is defective all gate diodes or both push pull transistors of a stage should be rep
60. input attenuators located in the front of the amplifier are fre quency compensated in each position Even small Capacitive changes can reduce the transmission perfor mance Faults of this kind are as a rule most easily detected with a square wave signal with a low repetition rate e g 1 kHz If a suitable generator with max output of 40V is available it is advisable to check at regular intervals the deflection coefficients on all positions of the input attenuators and readjust them as necessary A compen sated 2 1 series attenuator is also necessary and this must be matched to the input impedance of the oscillo scope This attenuator can be made up locally It is impor tant that this attenuator is shielded For local manufacture the electrical components required are 1 MQ 1 resis tor and in parallel with it a trimmer 3 5 pF in parallel with approx 20pF One side of this parallel circuit is connected directly to the input connector of the vertical amplifier and the other side is connected to the generator if possible via a low capacitance coaxial cable The series attenuator must be matched to the input impedance of the oscilloscope in the 5mV cm position variable control to CAL DC input coupling square tops exactly horizontal no ramp off is per mitted This is achieved by adjusting the trimmer located in the 2 1 attenuator Theshapeofthesguare waveshould then be the same in each input attenuator position Opera
61. iods of the signal are displayed A larger number unnecessarily decreases the brightness and maximum expansion The display of only a portion of a period limits the choice of the expanded time in terval and possibly complicates the triggering On the other hand the range of 1 to 3 basic periods can always be set un constrainedly with the TIME DIV switch In doing so the x10 expansion must be switched off temporarily X MAG x10 button is in out position In the X Section the HOLD OFF control should be set to min and the variable control to CAL The LEVEL control is adjusted so that stable triggering is ensured TRIG LED is illuminated The mode switch should now be set to the SEARCH posi tion it will be seen that the start of the display will shift to the right The amount of shift indicates the exact delay time MI3 604 H a display is not obtained in this mode then a lower delay time range should be selected For example when inves tigating the waveform shown in the figures a display could not be obtained with a delay time setting of 10 ms as the display is completely blanked However as a result of set ting the DELAY rotary switch to 0 1 us the shifting is not visible The DELAY range switch should then be rotated clockwise until the display starts just prior to the short time interval to be investigated The precise adjustment to the start is done with the VAR 10 1 delay time control The rotating range of the latter ha
62. ion CRT Board CRT Fassung TBG Board Zeitbasis Generator aktiv Zeitbasis Trennverst rker PTFS Board After Delay Trigger Halbbild Auswerter OS Board Option Overscan Anzeigen LED sl IL Board Option Rasterbeleuchtung Abk rzungen Abbreviations Al Ger testecker Appliance inlet Kondensator Capacitor Testpunkt Checkpoint CN Steckverbinder Connector D Br ckengleichrichter Bridge rectifier D Diode Diode Leuchtdiode Light emitting diode Fi Sicherung Fuse IC Integr Schaltung Integrated circuit hes Spule Drossel Inductor Coil Stecker Plug P L t se Eyelet R Widerstand Resistor 5 Schalter Switch Transistor Transistor TR Transformator Transformer VC Trimmkondensator Variable capacitor W Draht Wire 2 Zenerdiode Z Diode D D ERES HM604 Electrical components on certain parts of the HM604 are marked such that the first numeral is on Chassis Y inputs Trig ext input Appliance inlet Power switch Power transformer EY Board 1 1 Attenuator and Preamplifier Channel 11 Y intermediate amplifiers Channel selection flip flop Y Gate driver stages Chopper generator Trig and ext Trigger amplifier Trig gate driver stages LV Power Check point strip Component tester X Final amplifier TB Board Trigger circuit Timebase circuit passive Unblanking
63. ition 20 inclination the handle should be pulled to release it from the D position and swing backwards until it locks once more The handle may also be set to a position for horizontal carry ing by turning it to the upper side to lock in the B position At the same time the instrument must be moved upwards because otherwise the handle will jump back S 10 7 GI Subject to change without notice 0 Safety This instrument has been designed and tested in accor dance with Publication 348 Safety Requirements for Electronic Measuring Apparatus and has left the factory in a safe condition The present instruction manual contains important information and warnings which have to be fol lowed by the user to ensure safe operation and to retain the oscilloscope in safe condition The case chassis and all measuring terminals are connected to the protective earth contact of the appliance inlet The instrument operates ac cording to Safety C ass I three conductor power cord with protective earthing conductor and a plug with earthing con tact The mains line plug shall only be inserted in a socket outlet provided with a protective earth contact The protec tive action must not be negated by the use of an extension cord without a protective conductor Warning Any interruption of the protective conductor inside or outside the instrument or disconnection of the protective earth terminal is likely to make the instru
64. ive soldering tab bent over with a pair of pliers and subsequently fixed by soldering he minimum cross section of the protective earth con nection between the instruments power inlet and the connecting soldering tab on the rear chassis must be 0 81 mm in North America 0 75 in Western Europe The connecting soldering tab on the rear chassis has to be secured mechanically against loosening e g with lock washer Subject to change without notice After replacing the power transformer all remaining bits of wire solder and other foreign matter must be removed from the PCBs the vicinity of the power transformer and from within the insulating connecting box by shaking brushing and blowing Finally the top plate of the insulating connecting box has to be replaced Before connecting the instrument to the power supply replace the possibly defec tive fuse press the POWER button and make sure that there is an adequate insulation state between chassis safety earth conductor on the one hand and the live line pin as well as the neutral pin on the other Only after proper insulation has been established may further function tests with open chassis follow but with appropriate precaution ary measures 222422 Connection of the safety NN earth via long sold tab to rear chassis Appliance Inlet Safety Class Plug with earthing contact bk E 11 1 gt gt gt gt gt E
65. ks in combination with the oscilloscope and other instruments triggering of signal sources swept fre quency signal generators and so on The oscilloscope also contains a vertical output with BNC connector marked Y on the rear panel The output voltage is 50mV em display height into 509 It is picked off from the vertical amplifier like the trigger signal and it is similarly switchable Channel lor Il is selected with the pushbutton With alternate channel switching DUAL button in the Y Section depressed and al ternate triggering ALT button in the X Section depressed the vertical output is consecutively driven in time with the sweep period from Channel and Channel Il The vertical output is not dependent on the vertical trace position It does not respond to the adjustment of the Y POS I and Y POS II controls and to the depressing one of the INVERT buttons The vertical output is DC coupled and has approxi mately zero level to ground The bandwidth of the output is approx 60 MHz with 50 termination MI7 604 Test patterns Single Components Single Transistors Short circuit Resistor 510 2 Junction B C Junction B E Mains transformer prim Capacitor 33 uF Junction E C Single Diodes In circuit Semiconductors zu Z diode under 8V Z diode beyond 12V Diode paralleled by 68052 2 Diodes antiparallel Silicon diode Germanium diode Diode in series with 51 B
66. l Video signals are easily triggerable by the aid of the active TV sync separator TV SEP switch For optional operation as a DC or AC voltage amplifier each channel is provided with a DC AC coupling switch The DC position should only be used with an attenuator probe or at very low frequencies or if the determination of DC voltage content of the signal is absolutely necessary However when investigating very low frequency pulses misleading ramp offs may occur with AC coupling In this case DC operation is to be preferred if the signal voltage is not superimposed on a too high DC voltage level Other wise a capacitor of adequate capacitance must be con nected before the input of the vertical amplifier switched to DC coupling It should be remembered that this capacitor must have a sufficiently high breakdown voltage DC opera tion is also recommended for the display of logic and pulse signals particularly if their pulse duty factor changes perma nently during operation Otherwise the display will move up and down with any change DC voltages can only be measured in the DC position Amplitude Measurements In general electrical engineering alternating voltage data normally refers to effective values rms root mean square value However for signal magnitudes and voltage designations in oscilloscope measurements the peak to peakvoltage value is applied The latter corresponds to the real potential difference be
67. laced by selected components because otherwise there are possibly deviations of the specified data or func tions The HAMEG Service Department can give you advice for troubleshooting and replaceable parts Replacement parts can be ordered by letter or telephone from the nearest HAMEG Service Office Please supply the following infor mation Instrument type and serial number description of the part including function and location in the instrument quantity desired Replacement of the Power Transformer Should it be necessary to replace the mains line trans former the correct terminal sequence color identification for primary and secondary windings must be followed see diagram Power Supply and the figure below In addition the relevant Safety Regulations must be observed Here we refer only to those requirements relative to the parts conductively connected to the supply mains he construction of the instrument shall be such as to prevent any short circuiting or bridging of the insulation clearances or distances between those parts connected to the supply mains and any accessible con ductive parts due to accidental loosening or freeing of the wiring screws etc The rigidity of the mains wiring connections which may be subject to mechanical stresses shall not be depend ent upon the soldering alone To meet this requirement the bare ends of the wires must be pushed through the holes in the respect
68. lating screwdriver Caution High voltage Correct adjustment is achieved when the trace can be blanked while X Y pushbutton is depressed and in addi tion when the requirement described in the Test Instruc tions are met Astigmatism control The ratio of vertical and horizontal sharpness can be adjusted by the variable resistor VR603 located on the Z PCB see Adjusting Plan As a precaution however the voltage for the vertical deflecting plates approx 41 5V should firstly be checked because this voltage will affect the astigmastism correction Use the 1 MHz square wave signal from the built in calibrator via 10 1 probe for this cor rection Firstly adjust the sharpness of the horizontal square wave lines using the FOCUS control The sharpness of the verticallines should then be corrected with the aid of the Astigm pot VR626 HRepeat the correction several times in this sequence Adjustment has been correctly car ried out when on using FOCUS control only the sharpness is not improved in eitherdirection S1 604 Trouble Shooting the Instrument For this job at least an isolating variable mains line trans former protection class Il a signal generator an adequate precise multimeter and if possible an oscilloscope are needed This last item is required for complex faults which can be traced by the display of signal or ripple voltages As noted before the regulated high voltage and the supply voltage for the final
69. ltage 0 2V and 2V 1 Protective system Safety Class I IEC 348 Linevoltage 110 125 220 240V 10 Line frequency 50 to 60Hz Power consumption 40 Watt Weight approx 8kg Colour techno brown Cabinet W 285 H 145 D 380mm Lockable tilt handle Subject to change without notice 60 MHz Universal Oscilloscope 2 Channels 1 mV div Sensitivity Delay Line Component Tester Timebase 2 5s div to 5ns div including x10 Magnifier amp Sweep Delay Triggering DC 100MHz TV Sync Separator After Delay Trigger With its variety of operating and trigger modes the HM604 is a new in novative general purpose oscilloscope satisfying a wide range of exacting re quirements in laboratory production and service The dual channel measure ment amplifier ensures highly faithful waveform transfer characteristics which can be readily checked on the built in fast risetime 1 MHz Calibrator from probe tip to CRT screen Using Y axis magnification the instrument s high sensitivity enables stable displays of very small signals as low as 0 5 mV An analog output is provided for connecting multimeters or counters Another important feature is the internal delay line for observations of the leading edge of a signal As in dual time base oscilloscopes the HM604 features a calibra ted sweep delay mode allowing smallest waveform sections to be expanded up to 1000 times The HM 604 s most outstanding feature however is the unique newly
70. m should be displayed with X MAG x10 button released measurement in the 5us cm range When the X MAG x10 button is depressed a marker or cycle peak will be displayed every 10 cm 5 with variable control in CAL position measurement in the 5us cm range The tolerance is better measureable in the 50 us cm range one cycle every 1 Check the ramp output voltage on rear panel BNC connector marked by M with a Test Oscilloscope Test Scope set ting 1 V cm Timebase to one step slower sweep speed than on the HM 604 under test The latter must have no input and no trigger voltage free running sweep input coupling switch to GD The sawtooth voltage is applied with a BNC cable without termination from the ramp output connector to the input of the Test Scope The Test Scope should show a positive going linear sawtooth with an amplitude of approx 5 At the same time the function of the HOLD OFF con trol min max can be checked The hold off time variation cannot be measured precisely with this method because the unblanking pulse of the timebase generator is smaller than the ramp width Sweep Delay When the Sweep DELAY mode lever switch is set to the OFF mode the delay should have no effect on the display of the 1kHz calibration signal When the Sweep Delay is set in the SEARCH mode refer to Sweep Delay Operating Instruc tions it is possible to check the delay time by means of a dis tance measurement of the blanked bas
71. many cases However they are not so well defined This is caused by a shunt connection of real or complex impedances especially if they are of rela tively low impedance at 50 or 6 2 to the component under test often results differ greatly when compared with single components In case of doubt one component termi nal may be unsoldered This terminal should then be con nected to the insulated CT socket avoiding hum distortion of the test pattern Another way is a test pattern comparison to an identical cir cuit which is known to be operational likewise without power and any external connections Using the test prods identical test points in each circuit can be checked and a defect can be determined quickly and easily Possibly the device itself under test contains a reference circuit e g a second stereo channel push pull amplifier symmetrical bridge circuit which is not defective The test patterns on page M 18 show some typical displays for in circuit tests Subject to change without notice Miscellaneous posifive going sawtooth voltage of approximately 5 Maa coincident with display s sweep time is available at a BNC Output connector on the rear panel This ramp output is marked with AV The load impedance should not be less than 10 kQ Il 47 pF If the DC potential of the ramp output is not required a capacitor should be connected in series with the output The ramp output can be used for different measuring tas
72. max 500V Test Cable BNC BNC HZ34 Coaxial test cable length 1 m characteristic impedance 500 Cable capacitance 126pF Input voltage max 500V Adapter Banana BNC HZ20 Two 4mm binding posts 19mm between centers to standard BNC male plug input voltage max 500V 500 Through Termination HZ22 For terminating systems with 5052 characteristic impedance Maximum load 2 W Max voltage 1 OV Carrying Cases For HM 103 HZ95 For HM203 HM204 HM205 HM208 HM408 HM604 HM605 and HM 1005 HZ96 Viewing Hood HZ47 For HM203 HM204 HM205 HM208 HM408 HM604 HM605 and HM 1005 HZ60 2 For Checking the Y amplifier timebase and compensation of all probes the HZ60 2 is a crystal controlled fast rising typ 3ns square wave generator with switchable frequencies of DC 1 10 100Hz I IO I O0 kHz and 1 MHz Three BNC outputs provide sig nals of 25 mV into 50 62 0 25 V5 and 2 5 V5 open circuit for 1 Ox and 100x probes accuracy 1 Battery powered Scope Tester HZ65 Indispensable for trouble shooting in electronic circuits Single component and in circuit tests are both possible The HZ65 oper ates with all scopes which can be switched to X Y operation ext horizontal deflection Non destructive tests can be carried out on almost all semiconductors resistors capacitors and coils Two sockets provide for quick testing of the 3 junction areas in any small power transistor Other components are connected by
73. n AL nderungen vorbehalten Subject to change without notice 017 10 88 604 HM 604 BI x x aux du XE HI RM ENER a da A Z A M DER SN zum A a LIE S D H amp 10 vx NE BR ECT w s oe ES ER EM CE EISE zs E ER XT Si PE Best ckungsplan TB Board 3 Component Locations TB Board 3 EZ or c e
74. n timebase switch and the relation 1 T the following equations can be stated _ T L T Less EE 1 1 1 j L T L Te L F With X MAG x10 button depressed the T value must be divided by 10 However these four values are not freely selectable They have to be within the following limits L between 0 2 and 1 Ocm if possible 4 to 1 Ocm T between 5 ns and 1 Os F between 0 1 Hz and 60 MHz between 50 1 s cm 1 2 5 sequence with X MAG x 10 in out position and T between 5 ns cm and 100 ms cm 1 2 5 sequence with pushed X MAG x10 button Examples Displayed wavelength L 7 cm set time coefficient T 2 0 5 us cm required period T 7 0 5 10 3 5us required rec freq 1 3 5 10 5 286 kHz Signal period T 0 55 set time coefficient T 0 2 s cm required wavelength L 0 5 0 2 2 5cm Subject to change without notice Displayed ripple wavelength L 1 cm set time coefficient T 10 ms cm required ripple freq 1 1 10 10 7 100Hz TV line frequency F 15 625 Hz set time coefficient T 10 cm required wavelength L 1 15 625 1 07 6 4cm Sine wavelength L 2 min 4cm max 1 Ocm Frequency F 1 kHz max time coefficient T 1 4 103 0 25ms cm min time coefficient T 1 10 10 0 1 ms cm set time coefficient T 0 2 ms cm required wavelength L 1 1 03 0 2 1073 5 Displayed wavele
75. nces are only valid if the instrument has warmed up for 30 minutes at an ambient temperature between 15C and 1 30C Val ues not stating tolerances are typical for an average instrument Warranty Each instrument runs through a quality test with 10 hour burn in before leaving the production Practically every early failure is detected in intermittent operation by this method However it is possible that a component fails only after a lengthy operating period Therefore a functional guaran lee of 2 years is given for all units The condition for this is that no modifications have been made in the instrument In the case of shipments by post rail or carrier it is recom mended that the original packing is carefully preserved Transport damages and damage due to gross negligence are not covered by the guarantee In the case of a complaint a label should be attached to the housing of the instrument which describes briefly the faults observed If at the same time the name and telephone number dialing code and telephone or direct number or department designation is stated for possible queries this helps towards speeding up the processing of guarantee claims M2 Maintenance Various important properties of the oscilloscope should be carefully checked at certain intervals Only in this way is it largely certain that all signals are displayed with the accu racy on which the technical data are based The test methods described in the t
76. nd the knob for hol doff adjustment HOLD OFF The lower Y Section contains the controls for the vertical deflection system On the right and left in this section are lo cated vertical input connector DC AC GD input coupling slide switch Y POS control INVERT pushbutton at tenuator switch with variable control and ground jack All these controls and connectors exist in duplicate for each of the Channels and Il Three pushbuttons for selecting the operating mode are arranged below the attenuator switches CH TRIG DUAL and ADD These are explained later The instrument is so designed that even incorrect operation will not cause serious damage The pushbuttons control only minor functions and it is recommended that before commencement of operation all pushbuttons are in the out position After this the pushbuttons can be operated depending upon the mode of operation required Subject to change without notice The HM 604 accepts all signals from DC direct voltage up to a frequency of at least 60MHz 3dB For sinewave voltages the upper frequency limit will be 80MHz How ever in this higher frequency range the vertical display height on the screen is limited to approx 6cm The time re solution poses no problem For example with 100 MHz and the fastest adjustable sweep rate bns cm one cycle will be displayed every 2cm The tolerance on indicated values amounts to 3 in both deflection directions All valu
77. ng hour Larger deviations generally result from different characteristics of the dual FETs in both channel inputs to the Y amplifier To some extent fluctuations in drift are caused by offset current on the gate The drift is too high if the ver tical trace position drifts by more than 0 5mm on turning the appropriate attenuator switch through all 12 steps Sometimes such effects occur after long periods of opera tion Calibration of the Vertical Amplifier Two square wave voltages of 0 2mV and 2 V 1 are present at the output sockets of the calibrator CAL If a T1604 direct connection is made between the 0 2 mV output and the input of the vertical amplifier the displayed signal in the 50mV cm position variable control to CAL should be 4cm high DC input coupling Maximum deviations of 1 2 mm 3 are permissible If ax 10 probe is connected between the 2V output socket and Y input the same dis play height should result With higher tolerances it should first be investigated whether the cause lies within the amplifier or in the amplitude of the square wave signal On occasions it is possible that the probe is faulty or incorrectly compensated If necessary the measuring amplifier can be calibrated with an accurately known DC voltage DC input coupling The trace position should then vary in accordance with the deflection coefficient set With variable control at the attenuator switch fully counter clockwise the inp
78. ngth L O 8cm set time coefficient 0 5 us cm pressed MAG X 10 button T 0 05 us cm required rec freq 1 0 8 0 05 10 25 MHz required period T 1 25 1 09 40 ns If the time is relatively short as compared with the complete signal period an expanded time scale should always be applied X MAG x10 button pushed In this case the ascer tained time values have to be divided by 70 Very small time intervals at optional points of the signal can be measured more exactly with the aid of the sweep delay With it the display and measurement of time intervals which are smal ler than 1 96 of the full signal period are possible The small est measurable time interval is on the whole dependent on the obtainable brightness of the CRT The limit is an expan sion of approximately 1000 times Using a Viewing Hood HZ47 more expansion is possible provided that the time coefficient set on the TIME DIV switch is greater than 5us em and using the X MAG x 10 facility for the signal s basic period Otherwise the fastest sweep speed deter mines the greatest possible expansion When investigating pulse or square waveforms the critical feature is the risetime of the voltage step To ensure that transients ramp offs and bandwidth limits do not unduly influence the measuring accuracy the risetime is generally measured between 10 and 90 of the vertical pulse height For peak to peak signal amplitude of 6cm height whi
79. noperative A shortened hori zontal trace will be observed It is not necessary to discon nect scope input cables unless in circuit measurements are to be carried out In the CT mode the only controls which can be operated are INTENS FOCUS and X POS All other controls and settings have no influence on the test operation For the component connection two simple test leads with 4mm 2 banana plugs and with test prod alligator clip or sprung hook are required The test leads are connected to the insulated CT socket and the adjacent ground socket in the Y Section The component can be connected to the test leads either way round After use to return the oscilloscope to normal operation re lease the COMPONENT TESTER pushbutton Test Procedure Caution Do not testanycomponent in live circuitry re move all grounds power and signals connected to the component under test Set up Component Tester as stated above Connect test leads acoss component to be tested Observe oscilloscope display Only discharged capacitors should be tested A built in quick acting fuse protects the CT and the oscillo scope against mis operation e g device under test not dis connected from mains line supply In that case the fuse will blow For fuse replacement the oscilloscope has to be opened see service instruction page 1 Instrument Case Removal The fuse is located on the bottom side of the in strument close to the CT pushbutton Mak
80. o CAL Trigger complex or aperiodic signals using HOLD OFF control in normal trigger mode Horizontal xl 0 expansion X MAG x10 button depressed External horizontal deflection X Y operation with X Y button depressed X input via CH II Delay Operation OFF normal oscilloscope operation DELAY LED not illuminated SEARCH use DELAY range switch and VAR 10 1 fine control to select point of interest on displayed wave form DELAY LED flashing DELAY delayed signal now displayed Expansion obtained by rotating TIME DIV switch clockwise Press X MAG x10 button if necessary DELAY LED illuminated DEL TRIG After Delay Triggering together with TV SEP selection of trigger slope Component Tester Press COMPONENT TESTER button Connect both component terminals to CT and ground jacks n circuit test Circuit under test must be disconnected to battery or power pull out power plug signals and ground earth Remove all signal connections to HM 604 cable probe then start testing Subject to change without notice K1 604 Test Instructions General These Test Instructions are intended as an aid for checking the most important characteristics of the HM 604 at regular intervals without the need for expensive test equipment Resulting corrections and readjustments inside the instru ment detected by the following tests are described in the Service Instructions or on the Adjusting Plan They should only be undertaken by qualif
81. o CN CN c a 3 TT Pushbutton see diagram POWER SUPPLY power switch 4A 24A _ 250v Rear View of Power Switch and Appliance Inlet with Voltage Selector and Fuse Subject to change without notice Adjustments As advised in the Operating Test and Service Instructions small corrections and adjustments are easily carried out with the aid of the Circuit Diagrams and Adjusting P an However a complete recalibration of the scope should not be attempted by an inexperienced operator but only some one with sufficient expertise Several precision measuring instruments with cables and adapters are required and only then should the pots and trimmers be readjusted provided that the result of each adjustment can be exactly deter mined Thus for each operating mode and switch position a signal with the appropriate sine or square waveform fre quency amplitude risetime and duty cycle is required 53 604 eBueuo o1 yoslgns 709 8801 IQ CT IN CH H CALIBRATOR Y Y OUT OUT CIRCUIT gerichtetes DC Signal directed DC signol gerichtetes AC Signal directed AC signal gerichtet mech verbunden directed mechanical coupled d Doppelleitung sym Signalweg twin lead sym signal path nderungen vorbehalten Subject to change without notice 5v POWER DC Section gt T7 S
82. o correctly engaged The use of repaired fuses or short circuiting the fuse holder is not allowed Dam age arising because of this is not covered by the guarantee Fuse type Size 5 x 20 mm 250 V C IEC 127 Sheet Ill DIN 41 662 possibly DIN 41 571 sheet 3 Cutoff time lag T Line voltage Fuse rating 110 V 10 TO 63 A 125V 10 TO 63 A 220 V 10 T0 315A 240 V 10 T0 315 A Subject to change without notice Type of Signal All types of signals with a frequency spectrum below 60 MHz can be displayed on the HM 604 The display of sim ple electrical processes such as sinusoidal RF and AF sig nals or ripple poses no problems However when square or pulse shaped signals are displayed it must be remembered that their harmonic content must also be transmitted In this case the bandwidth of the vertical amplifier must be considerably higher than the repetition frequency of the sig nal In view of this accurate evaluation of such signals with the HM 604 is only possible up to a maximum repetition rate of 6 MHZ Operating problems can sometimes occur when composite signals are to be displayed especially if they do not contain any suitable level components and repetition frequency which can be used for triggering This occurs for example with burst signals To obtain a stably triggered dis play in these cases it may be necessary to use Normal Trig gering HOLD OFF time control and or TIME DIV variable contro
83. oc eee P3 7 1 R3345 BC x 5 Fra 12V TB Stop CO PCB Trig LED 1 HO Comp Dischorge C3162 ur ni Oscilloscope A D IC 74ALSOO Datum 10 AL cre SOV types Time Base Board Date Mhsn 29 06 1988 e Kond en M nn d All 10uF TE 35V types 3 HM 604 J Bruder Alle 10uF Elkos haben S5V 1 Sheet of J Waldschmitt nderungen vorbehalten Subject to change without notice Best ckungsplan PTFS Board HM 604 Component Locations PTFS Board L tseite Best ckungsseite Soldering side Component side 016 10 88 604 nderungen vorbehalten Subject to change without notice Palgns usyeyaqioa ueBuniepuy 709 880L mm O eee ee Oe GES AD IE ee 8 HE CE WED eee GE u 71 2434 1KHz 1MHz kom XY Boord R2064 Ll 12V 6RB 0 73V 82109 C2043 N 0 1 250V owes mmm ee P ue a L Calibrator PCB 4 oe 5 1 r od 71 Zen Tene 104 3s B q 3 L 2 9 R2107 0 1 i E gt d i 1 3 2 02 R2108 3 al m Wired Cap 7V R2114 vd el
84. ontal system makes accurate measurements dif ficult In this mode one of the sinewave signals provides horizontal deflection X while the other signal provides the vertical deflection Y BOX The phase angle between the two signals can be deter mined from the Lissajous pattern as follows sin cos p 1 arc sin This simple formula works for angles less than 90 it is independent from both deflection amplitudes on the screen Caution If a single spot appears both deflection voltages are missing reduce the intensity immediately as a high intensity setting may cause damage to the fluorescent screen of the CRT Dual Trace Phase Difference Measurements Phase comparison between two signals of the same fre quency can be made using the dual trace feature DUAL button depressed This method of phase difference meas urement can be used up to the frequency limit of the vertical system To make the comparison use the following proce dure Set the Input Coupling switches to the same position and the CH V II TRIG pushbutton to the channel where the reference signal Phase 0 is connected Select ALT chan nel switching for frequencies above 1 kHz and CHOP for frequencies below 1 kHz Use probes which have equal time delay to connect the signals to the input connectors Set the Input Attenuator switches and the CH and CH II var iable controls so that the displays are approximately
85. paired if for example the instrument shows visible damage fails to perform the intended measurements has been subjected to prolonged storage under un favourable conditions e g in the open or in moist envi ronments has been subject to severe transport stress e g in poor packaging M Operating conditions The instrument has been designed for indoor use The permissible ambient temperature range during opera tion is 15 30 C It may occasionally be subjected to temperatures between 10 C and 10 C without degrad ing its safety The permissible ambient temperature range for storage or transportation is 40 C 70 C The maximum operating altitude is up to 2200m non operating 15000m The maximum relative humidity is up to 80 If condensed water exists in the instrument it should be acclimatized before switching on In some cases e g extremely cold oscilloscope two hours should be allowed before the instrument is put into operation The instrument should be kept in a clean and dry room and must not be operated in explosive corrosive dusty or moist environ ments The oscilloscope can be operated in any position but the convection cooling must not be impaired The ven tilation holes not be covered For continuous opera tion the instrument should be used in the horizontal posi tion preferably tilted upwards resting on the tilt handle The specifications stating tolera
86. played signal 5 Fig 2 adjusting the 9 A HOLD OFF time A Fig 1 shows a case where the HOLD OFF knob is in the XI position and var ious different waveforms are overlapped on the screen making the signal observation unsuccessful Fig 2 shows a case where only the desired parts of the signal are stably dis played Sweep Delay After Delay Triggering With the sweep delay the start of the sweep can be de layed from the trigger point by a selectable time 100ns to maximum 1 s Itis therefore possible to start the sweep at practically any point of a waveform The interval which fol lows the start of the sweep can be greatly expanded by the increase of the sweep speed From the 5 p cm TIME DIV range downwards to slower sweep speeds an expansion of atleast 100 times and with the aid of the X MAG x10 ex pansion of 1000 times is possible With time coefficients higher than bus cm the maximum expansion increases proportionally However with increasing the expansion the display brightness decreases Under very high ambient light conditions a Viewing Hood like HZ47 can overcome this problem It should be noted that there are some difficulties with higher expansions if the test signal has inherent jitter To reduce or eliminate this jitter expanded parts of a signal can be triggered again after delay provided there is another suitable edge DEL TRIG Subject to change without notice
87. plies for the rear of the case on which the rear cover is put Caution During opening or closing of the case the instrument must be disconnected from all power sources for maintenance work or a change of parts or components If a measurement trouble shooting or an adjustment is unavoidable this work must be done by a specialist who is familiar with the risk involved When the instrument is set into operation after the case has been removed attention must be paid to the accel eration voltage for the CRT 12 5kV and to the operating voltages for both final amplifier stages together 140 V Potentials of these voltages are on the CHT socket on the upper and the lower horizontal PCBs and on the lateral PCB directly beside the CRT neck High voltages of max 2000 V are at the INTENS and FOCUS potentiometers They are highly dangerous and therefore precautions must be taken It should be noted furthermore that shorts occuring on different points of the CRT high voltage and unblanking circuitry Will definitely damage some semiconductors For the same reason it is very risky to connect capacitors to these points while the instrument is on Capacitors in the instrument may still be charged even when the instrument is disconnected from all voltage sources Normally the capacitors are discharged 6 sec onds after switching off However with a defective instrument an interruption of the load is possible Subject to change witho
88. raticule lines See Fig above for 1 kHz The signal amplitude shown should be 4cm 1 2 mm 3 96 During this adjustment the signal edges will remain invisible Adjustment at 1 MHz Probes HZ51 52 and 54 will also allow for HF adjustments They incorporate resonance deemphasizing networks R trimmer in conjunction with inductances and capacitors which permit for the first time probe compensation in the range of the upper frequency limit of the vertical oscillo scope amplifier Only this compensative adjustment ensures optimum utilisation of the full bandwidth together with constant group delay at the high frequency end thereby reducing characteristic transient distortion near the leading signal edge e g overshoot rounding ringing holes or bumps to an absolute minimum Using the probes HZ51 52 and 54 the full bandwidth of the HM 604 can be utilized without risk of Unwanted wave form distortion Prerequisite for this HF adjustment is a squarewave generator with fast risetime typical 4ns and low output impedance approx 5062 providing 0 2V and 2V at a fre quency of approx 1 MHz The calibrator output of the HM604 meets these requirements when the pushbutton 1 MHz is depressed Connect the probe HZ51 52 or 54 to CH 1 input Depress the calibrator pushbutton 1MHz All other pushbuttons should be released out position Set the input coupling switch to DC attenuator switch to 5mV cm TIME DIV
89. red trace may not align exactly with the horizon tal center line of the graticule A few degrees of mis alignment can be corrected by a potentiometer acessi ble through an opening on the front panel marked TR DC Balance Adjustment The vertical preamplifiers for and contain matched dual FETs connected as input source followers After long periods of use the FET characteristics may change which can alter the DC balance of the vertical amplifier A quick check of DC Balance can be made on each channel by pulling the fine amplitude control MAG x5 and pushing it back If the trace moves from the vertical position up or down more than 1 mm the DC Balance will require readjustment This check should be made after a 20 minute warm up period Adjustment procedure The following instructions should be performed to obtain the correct DC balance adjustment of both channels Remove all input cables and adjust oscilloscope controls to display the baseline Center the baseline using Y POS and X POS controls Set attenuator switches to 5mV cm and input coupling switches to GD Release all pushbuttons in the Y Section Place the oscilloscope so that it rests firmly on its back up right position and locate DC balance adjustment poten tiometer access holes marked DC BALANCE which are found underneath the instrument nsert a screwdriver blade approx 3mm length min 20 mm in
90. riggeringe MI 3 Replacement of Components and Parts 52 Delay Mode Indication MI 5 Replacement of the Power Transformer 52 Component 5 Adjustments o3 Miscellaneous MI 7 Test CPallems 4 uum quove x SES MI 8 Circuit Diagrams Diagfam ae OR Sloe D 1 Short Instruction K 1 Wiring Diagram 002 008 D2 Front Panel Elements Identification of Components D 3 Folder with Front View K 2 Y Input Attenuator Preamplifier D 4 Test Instructions Y intermediate Amplifiers Trigger Pre Amplifiers General Ge wet Ben CR T1 Component Tester D 5 Cathode Ray Tube Brightness Focus X Final Amplifier D 6 Linearity Raster Distortions T 1 Post Trigger Field Selector D 7 Astigmatismus Check 1 Timebase analog D 8 Symmetry and Drift of the Vertical Amplifier T1 Timebase D 9 Calibration of the Vertical Amplifier 2 2 T1 Timebase Generator D10 Transmission Performance of the Vertical Amplifier X Final Amplifier Calibrator D11 chew Se ee ke de ow T 2 CRT and HV circuit 2222 12 Operating Modes CH I II TRIG DUAL ADD Power D13 CHOP
91. s the calibrator of the HM 604 can under certain conditions replace expensive squarewave generators when testing or compensating wideband attenuators or amplifiers In such a case the input of an appropriate circuit will be connected to one of the CAL out puts via a suitable probe The voltage provided at a high impedance input I MQ 1115 50 pF will correspond to the division ratio of the probe used 10 1 20mV 100 1 also 20mV from 2V output Suitable probes are HZ51 52 53 and 54 For low impedance inputs e g 50 1 1 probe can be employed which however must be fully terminated with a 50 Q through termination Suitable probe types are HZ50 and HZ54 The latter must be switched to the 1 1 position and the HF trimmer in the connecting box turned fully coun terclockwise When connected to the 0 2V CAL socket and using the HZ50 this arrangement will provide approx 40 at 50 Q circuit input and approx 24mV if the HZ54 is used The voltages given here will have larger tolerances than 1 since operation of a 1 1 probe together with a 50 Q load is very uncommon Using the 2V CAL socket under similar conditions is only possible with the HZ54 probe The potential obtained at the 50Q input will then be approx 190 mV but with almost twice the risetime Accurate readings of the available input voltage can be shown directly on the HM604 when con necting a 50Q through termination between the BNC plug o
92. s closed case an angle of rota tion 0 57 1 mm difference in elevation per 10cm graticule length is sufficient for the compensation of the earth s magnetic field Miscellaneous Y output A check of the Y output rear panel is possible on the screen using the dual channel mode by means of the calibrator sig nal To this a connection is made from the calibrator socket 0 2 V 1kHz to the input connector and using a BNC BNC cable and a 50 through termination a second con nection from the Y output to input connector Set tings attenuator switch to 50mV cm attenuator switch to 0 1 V cm input coupling to DC CH II input coupling to GD TIME DIV switch to 0 5ms cm automatic triggering LEVEL knob in AT position TRIG selector to AC no button depressed Now the square wave signal is visible with 4cm display height With Y POS I control the tops of the square wave are adjusted to 2cm from the horizontal center line of the graticule Then the DUAL button has to be pressed The appearing second trace without signal is adjusted to 2cm using the Y POS lIl control Then the input coupling is set to DC Now the signal across the Y out put appears with the same phase position as the calibrator signal via Channel As well as the DC offset e g 0 8cm amp 80 the amplitude e g 2cm 40 2V of the Y output can be measured In the example the sensivity of the Y out put can be
93. s no stop On the range limits a certain snapping noise is audible Initially this control should be set in the left start position In the SEARCH mode the LED indicator will flash Figure 2 MODE SEARCH DELAY range Ims TIME DIV 0 5 ms cm LED flashing Delay time 2 5cm 0 5ms cm 1 25ms In figure 2 it can be seen that the delay time is also measur able as the blanked portion or apparent shift of the start of the trace This time can be determined by multiplication of the horizontal shifting in cm by the time coefficient set on the TIME DIV switch Now the mode switch can be set to DELAY In this mode the LED is permanently illuminated The display will now shift to the left and the trace will commence in the same po sition as for a normal display however the short time inter val under investigation now starts on the first or left vertical graticule line Figure 3 MODE DELAY DELAY range 1ms TIME DIV 0 5 ms cm LED illuminated MI4 604 If the timebase sweep speed is increased rotate TIME DIV switch clockwise then the short time interval will be expanded It may be found that as the amount of expansion is increased the trace will tend to shift If this happens the VAR delay time control can be readjusted also sub sequently at any time to enable the exact point of interest to be displayed In the example shown in figure 4 it can be seen that an ex pansion of x70 was o
94. splayed If DC coupling is selected it is advisa ble to use the normal triggering mode In the HF coupling mode a high pass filter is switched into the trigger amplifier This filter cuts off the DC content of the trigger signal and the lower frequency range In the LF coupling mode a low pass filter is switched into the trigger amplifier This filter cuts off any amplifier noise and the frequency range of the trigger signal above 50 kHz For the purpose of line triggering TRIG lever switch in the X Section to a divided secondary voltage of the power transformer is used as a trigger signal This trigger mode is independent of the signal amplitude or display height and al lows a display below the internal trigger threshold Line triggering is recommended for all signals which are time re lated multiple or submultiple to the mains line frequency or when it is desirable to provide a stable display of a line MI2 604 frequency component in complex waveforms Therefore it is especially suited for the measurement of small ripple volt ages from power supply rectifiers or of magnetic or static leakage fields a circuit In some countries the standard power plug has symmetri cally arranged plugs interchanging of Line and Neutral is possible In such cases the SLOPE pushbutton may indicate the wrong polarity compared with the display trig gering with falling edge instead of rising edge For correc tion the power
95. stages are highly dangerous Therefore it is recommended to use totally insulated extended probe tips when trouble shooting the instrument Acci dental contact with dangerous voltage potentials is then unlikely Of course these instructions cannot thoroughly cover all kinds of faults Some common sense will certainly be required when a complex fault has to be investigated If trouble is suspected visually inspect the instrument thoroughly after removal of the case Look for loose or badly contacted or discolored components caused by overheat ing Check to see that all circuit board connections are mak ing good contact and are not shorting to an adjacent circuit Especially inspect the connections between the PCBs to the power transformer to front chassis parts to CRT sock et to trace rotation coil inside of CRT s shielding to the 3 BNC connectors at the rear chassis and to the control potentiometers and switches on top of and beneath both main PCBs Furthermore the soldering connections of the transistors and Fixed Three Terminal Regulators resp on the rear chassis This visual inspection can lead to success much more quickly than a systematic fault location using measuring instruments Prior to any extensive trouble shooting also check the external power source If the instrument fails completely the first and most impor tant step after checking the mains line voltage and power fuse will be to measure the deflect
96. switch to 0 1 us cm Set all variable controls to CAL position Insert the probe tip into the output socket marked 0 2V A waveform will be displayed on the CRT screen with leading and trailing edges clearly visible For the HF adjustment now to be performed it will be necessary to observe the ris ing edge as well as the upper left corner of the pulse top To gain access to the HF compensation trimmer the plastic cover of the probe connecting box has to be slid off after unscrewing the probe cable The connecting boxes of the HZ51 and HZ54 contain one R trimmer screw each while that of the HZ52 provides three These R trimmers have to be adjusted in such a manner that the beginning of the pulse top is as straight as possible Overshoot or excessive round ing are unacceptable This is relatively easy on the HZ51 and HZ54 but slightly more difficult on the HZ52 The rising edge should be as steep as possible with the pulse top remaining as straight and horizontal as possible On the HZ52 each of the three trimmers has a clearly Subject to change without notice defined area of influence on the waveform shape see Fig offering the added advantage of being able to straighten out waveform aberrations near the leading edge Adjustment points of the probes HZ51 HZ54 Osc NF CAL T HF LF T T LF 10ns cm HF 4 alters the middle frequencies alters the le
97. the X MAG x10 button a tenfold expansion of the desired signal section is possible without any change of trig gering or timebase This can be of assistance with compli cated or difficult to trigger signals Subject to change without notice Operation of the sweep delay needs some experience par ticularly with composite signals However the display of sections from simple signal waveforms is easily possible It is recommended to operate only the sequence OFF SEARCH DELAY because otherwise location of the short time interval to be investigated will be relatively difficult The sweep delay facility can be used in the following modes Mono Dual and Algebraic Addition 1 1 Delay Mode Indication Both operating modes of the sweep delay are indicated with an LED located to the right of the DELAY mode lever switch In SEARCH position the LED will flash This is an in dication of the temporary operating state The DELAY posi tion is indicated by constant lighting of the LED However should this be noted and normal operating mode is re quired then the change over of the lever switch to its OFF position has been overlooked This could cause errors in dis playing a signal by complete or partial blanking This indica tion therefore should be closely observed Component Tester General The HM 604 has a built in electronic Component Tester ab breviated CT which is used for instant display of a test pat tern to indicate wheth
98. then eliminated Hum or interference voltage appearing in the measuring cir cuit especially with a small deflection coefficient is possi bly caused by multiple grounding because equalizing cur rents can flow in the shielding of the measuring cables volt age drop between non fused earthed conductors of other line powered devices which are connected to the oscillo scope or test object e g signal generators with anti inter ference capacitors Operating For a better understanding of these Operating Instructions the front panel picture at the end of these instructions can be unfolded for reference alongside the text The front panel is subdivided into three sections according to the various functions The INTENS FOCUS and TR trace rotation controls are arranged on the left directly below the screen of the cathode ray tube CRT Continuing towards the right are the horizontal magnification button X MAG x10 the switch for calibrator frequency selection 1 kHz 1 MHz and calibrator output sockets 0 2V 2V CAL The COMPONENT TESTER pushbutton and its measuring socket are located on the right side The X Section located on the upper right next to the screen contains the red POWER pushbutton and indicating LED all controls for timebase TIME DIV triggering TRIG hori zontal trace position X POS sweep delay DELAY TV separator TV SEP together with the field select button FIELD I II the XYmode button XV a
99. ting Modes CH I Il TRIG I Il DUAL ADD CHOP INV I H and X Y Operation On depressing the DUAL pushbutton two traces must appear immediately On actuation of the Y POS controls the trace positions should have no effect on each other Nevertheless this cannot be entirely avoided even in fully serviceable instruments When one trace is shifted verti cally across the entire screen the position of the other trace must not vary by more than 0 5 mm A criterion in chopped operation is trace widening and shadowing around and within the two traces in the upper or lower region of the screen Set TIME DIV switch to 1 us cm depress the DUAL and CHOP pushbutton set input coupling of both channels to GD and advance the INTENS control fully clockwise Adjust FOCUS for a sharp display With the Y POS controls shift one of the traces to a 2 cm the other to a 2cm vertical position from the horizontal center line of the graticule Do not try to synchronize the chop frequency 500kHz Then alternately release and depress the CHOP pushbutton Check for negligible trace widening and periodic shadowing in the chopped mode It is important to note that in the LEI add mode only ADD depressed or the I I difference mode INVERT CH button depressed in addition the vertical position of the trace can be adjusted by using both the Channel and Chan nel II Y POS controls If a trace is not visible in either these modes the overscanning L
100. tit is the total measured risetime tsc is the risetime of the oscilloscope amplifier approx 5 8ns and t the risetime of the probe e g 2 ns If Le is greater than 42 ns then can be taken as the risetime of the pulse and calcu lation is unnecessary Calculation of the example in the figure above results in a signal risetime t V 32 5 82 2 54 ns Connection of Test Signal Caution When connecting unknown signals to the oscillo scope input always use automatic triggering and set the DC AC input coupling switch to AC The attenuator switch should initially be set to 20V cm Sometimes the trace will disappear after an input signal has been applied The attenuator switch must then be turned back to the left until thevertical signal height is only 3 8cm With a signa amplitude greater than 160V an attenuator probe must be inserted before the osciloscope s vertical input If after applying the signal the trace is nearly blanked the period of the signal is probably substantially Subject to change without notice M5 604 longer than the set value on the TIME DIV switch It should be turned to the left to an adequately greater time coefficient The signal to be displayed should be fed to the vertical input of the oscilloscope by means of a shielded test cable e g the HZ32 or HZ34 or by a x 10 or x 100 attenuator probe The use of these shielded cables with high impedance cuits is only recomm
101. trigger point lies on the starting edge of a sync pulse if SLOPE button is in position As mentioned before in TV V mode an integrating network is additionally added to the sync separator which delays the formed trigger pulse by about 50 5 Video signals are triggered in the automatic mode There fore the adjustment of the trigger point is superfluous The internal triggering is virtually independent of the display height which may differ from 0 8 to 8div As opposed to AT mode when in normal mode the screen is blanked without signal at the input turning the LEVEL knob is ineffectual Subject to change without notice Function of var HOLD OFF control If it is found that a trigger point cannot be located on ex tremely complex signals even after repeated and careful ad justment of the LEVEL control in the Norma Triggering mode a stable display may be obtained using the HOLD OFF control in the X Section This facility varies the hold off time between two sweep periods up to the ratio gt 5 1 Pulses or other signal waveforms appearing during this off period cannot trigger the timebase Particularly with burst signals or aperiodic pulse trains of the same amplitude the start of the sweep can be shifted to the optimum or re quired moment After specific use the HOLD OFF control should be re set into its calibration detent min otherwise the brightness of the display is reduced drastically 1 78 parts dis
102. tween the most positive and most negative points of a signal waveform Subject to change without notice H a sinusoidal waveform displayed on the oscilloscope sc reen is to be converted into an effective rms value the re sulting peak to peak value must be divided by 2 2 2 83 Conversely it should be observed that sinusoidal volt ages indicated V ms Ver have 2 83 times the potential dif ference in V The relationship between the different volt age magnitudes can be seen from the following figure AA N m 0 N i Vmom MEME CREME B HA IIND Voltage values of a sine curve effective value simple peak or crest value peak to peak value Vmom Momentary value The minimum signal voltage required at the vertical amplifier input for a display of 1 cm is approximately ImV This is achieved with the attenuator control set at 5mV cm its var iable control in the fully clockwise position and pulled out However smaller signals than this may also be dis played The deflection coefficients on the input attenuators are indicated in mV cm or V cm peak to peak value The magnitude of the applied voltage is ascertained by multiplying the selected deflection coefficient by the vertical display height in cm If an attenuator probe x 70 is used a further multiplica tion by a factor of 70 is required to ascertain the correct voltage value For exact amplitude measur
103. ut notice Therefore after switching off it is recommended to con nect one by one all terminals of the check strip across 1 kQ to ground chassis for a period of 1 second Handling of the CRT needs utmost caution The glass bulb must not be allowed under any circumstances to come into contact with hardened tools nor should it undergo local superheating e g by soldering iron or local undercooling e g by cryogenic spray We recom mend the wearing of safety goggles implosion danger Operating Voltages Besides the two AC voltages for the CRT heating 6 3V and graticule illumination Component Tester and line triggering 12V there are eight electronically regulated DC operating voltages generated 12V 5 5V 12V 68V 140V 1800V and 10 4 kV These different operating voltages are fixed voltages except the 12V which can be adjusted The variation of the fixed voltages greater than 2 96 from the nominal value indicates a fault This voltage is measured on the checkpoint strip located on XY Board with reference to ground Measurements of the high volt age may only be accomplished by the use of a sufficient highly resistive voltmeter gt 10M amp You must make abso lutely sure that the electric strength of the voltmeter is suf ficiently high Minimum Brightness The variable resistor VR 601 located on the Z PCB is used for this adjustment procedure It may only be touched by a properly insu
104. ut sensitivity is decreased at least by the factor 2 5 in each position In the 50mV cm position the displayed calibrator signal height should vary from 4cm to at least 1 6cm When pulling the Y expansion x5 knob MAG x5 the sen sitivity is increased by the factor 5 In the 0 2V cm position the displayed signal should change from 1 cm to 5cm by pulling the MAG x5 knob Transmission Performance of the Vertical Amplifier The transient response and the delay distortion correction can only be checked with the aid of a square wave generator with a fast risetime max 5ns The signal coaxial cable e g HZ34 must be terminated at the vertical input of the oscilloscope with a resistor equal to the characteristic impedance of the cable e g with HZ22 Checks should be made at 1 OOHz 1 kHz 10 kHz 100 kHz and 1 MHz the deflection coefficient should be set at 5mV cm with DC input coupling Y variable control in CAL position In so doing the square pulses must have a flat top without ramp off spikes and glitches no overshoot is permitted espe cially at 1 MHz and a display height of 4 5 At the same time the leading top corner of the pulse must not be rounded In general no great changes occur after the instru ment has left the factory and it is left to the operator s dis cretion whether this test is undertaken or not Of course the quality of the transmission performance is not only dependent on the vertical amplifier The
105. when no signal is present In this position it is possible to obtain stable displays of virtually all uncompli cated periodically repeating signals above 30 Hz Adjust ments of the timebase then are limited to timebase setting With normal triggering LEVEL knob not in AT position and LEVEL adjustment triggering of time div deflection can be set in any point of a given signal The triggering range which can be set with the LEVEL control depends greatly on the amplitude of the displayed signal If it is less than 1 div then the range is quite small and performance of settings re quires a delicate touch If the LEVEL control is incorrectly set no trace will be visi ble In order to obtain a satisfactory stable display the timebase must be triggered synchronously with the test signal The trigger signal can be derived from the test signal itself when internal triggering is selected or from a frequency re lated signal applied to the external trigger input 604 Triggering can be selected on either the rising or falling edge of the trigger signal depending on whether the SLOPE pushbutton next to LEVEL is in the out or in position In the out position triggering from the positive going edge is selected The correct slope setting is important in obtaining a display when only a portion of a cycle is being displayed With internal triggering in the Mono channel mode on the Y amplifier the trigger signal is derived from the

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