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6

Subject to change without notice

Symbols

See user's manual

Danger high voltage

Earth

General Information

This oscilloscope is easy to operate. The logical
arrangement of the controls allows anyone to quickly
become familiar with the operation of the instrument,
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
interior. If there is transport damage, the supplier must be
informed immediately. The instrument must then not be
put into operation.

Use of tilt handle

To view the screen from the best angle, there are three
different positions (C, D, E) for setting up the instrument. If
the instrument is set down on the floor after being carried,
the handle automatically remains in the upright carrying
position (A).
In order to place the instrument onto a horizontal surface, the
handle should be turned to the upper side of the oscilloscope
(C). For the D position (10° inclination), the handle should be
turned to the opposite direction of the carrying position until
it locks in place automatically underneath the instrument. For
the E position (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
carrying by turning it to the upper side to lock in the B
position. At the same time, the instrument must be lifted,
because otherwise the handle will jump back.

Safety

This instrument has been designed and tested in accor-
dance with 

IEC Publication 348, Safety Requirements

for Electronic Measuring Apparatu

s. The CENELEC

HD401 regulations correspond to this standard. It has left
the factory in a safe condition. This instruction manual
contains important information and warnings which have
to be followed by the user to ensure safe operation and to
retain the oscilloscope in a safe condition. The case,
chassis and all measuring terminals are connected to the
protective earth contact of the appliance inlet. The
instrument operates according to 

Safety Class I

 (three-

conductor power cord with protective earthing conductor
and a plug with earthing contact). The mains/line plug shall
only be inserted in a socket outlet provided with a protective
earth contact. The protective action must not be negated
by the use of an extension cord without a protective
conductor.

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/live, neu-
tral) of the instrument have been tested against insulation
breakdown with 2200V DC.

Under certain conditions, 50Hz or 60Hz hum voltages
can occur in the measuring circuit due to the inter-
connection with other mains/line powered equipment
or instruments. This can be avoided by using an isolation
transformer (Safety Class II) between the mains/line
outlet and the power plug of the device being
investigated.

Most cathode-ray tubes develop X-rays. However, 

the

dose equivalent rate falls far below the maximum
permissible value of 36pA/kg (0.5mR/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 likely
to be impaired if, for example, the instrument

shows visible damage,

fails to perform the intended measurements,

has been subjected to prolonged storage under
unfavourable conditions (e.g. in the open or in moist
environments),

has been subject to severe transport stress (e.g. in poor
packaging).

Operating Instructions

Summary of Contents for HM 303-4

Page 1: ...ge 8 Amplitude Measurements 8 Time Measurements 9 Connection of Test Signal 10 First Time Operation 12 Trace Rotation TR 12 Probe compensation and use 12 Operating Modes of the Y Amplifier 14 X Y Oper...

Page 2: ...ual for a reduced cable length the maximum cable length of a dataline must be less than 3 meters long If an interface has several connectors only one connector must have a connection to a cable Basica...

Page 3: ...WG Low Voltage Equipment Directive 73 23 EEC amended by 93 68 EEC Directive des equipements basse tension 73 23 CEE amend e par 93 68 CEE Angewendete harmonisierte Normen Harmonized standards applied...

Page 4: ...nal Features Component Tester 1kHz 1MHz Calibrator OSCILLOSCOPES Specifications Vertical Deflection Operating modes Channel I or II separate both Channels alternated or chopped Chopper frequency appro...

Page 5: ...prox 500M DC 1MHz max 15kV DC peakAC HZ47 Viewing Hood for Oscilloscopes HM205 408 604 1 2 1005 and 1007 HZ48 Viewing Hood for Oscilloscopes 303 304 305 604 3 and 1004 during transpor tation of an osc...

Page 6: ...is standard It has left the factory in a safe condition This instruction manual contains important information and warnings which have to be followed by the user to ensure safe operation and to retain...

Page 7: ...tment designation isstatedforpossiblequeries thishelpstowards speeding up the processing of guarantee claims Maintenance Variousimportantpropertiesoftheoscilloscopeshouldbe carefully checked at certai...

Page 8: ...However forsignalmagnitudesandvoltage designations in oscilloscope measurements the peak to peak voltage Vpp value is applied The latter corresponds to the real potential difference between the most...

Page 9: ...he attenuator series resistor will break down causingdamagetotheinputoftheoscilloscope However if for example only the residual ripple of a high voltage is to be displayed on the oscilloscope a normal...

Page 10: ...must be divided by 10 The fall time of a pulse can also be measured by using this method The following figure shows correct positioning of the oscilloscope trace for accurate risetime measurement tr...

Page 11: ...obecompensation page M7 Standard attenuator probes on the oscilloscope normally reduce its bandwidth and increase the rise time In all cases where the oscilloscope bandwidth must be fully utilized e g...

Page 12: ...ion required The HM303 accepts all signals from DC direct voltage up to a frequency of at least 30MHz 3dB For sinewave voltages the upper frequency limit will be 50MHz 6dB However in this higher frequ...

Page 13: ...should then be 4 div 0 12div 3 During this adjustment the signal edges will remain invisible Adjustment at 1MHz Probes HZ51 52 and 54 can also be HF compensated They incorporate resonance de emphasing...

Page 14: ...the 3 pushbuttons CH I II DUAL and ADD in the Y field of the front panel For Mono mode all 3 buttons mustbeintheirreleasedpositions onlychannelIcanthen beoperated ThebuttonCHI II TRIG I IImustbedepres...

Page 15: ...in the X Y mode can exceed an angle of 3 above 120 kHz It cannot be seen as a matter of course from the screen display if the test voltage leads or lags the reference voltage A CR network before the...

Page 16: ...o buttons Y CH I 20mV div AC TIME DIV 0 2ms div Triggering NORMAL with LEVEL setting internal or external triggering Figure 2 Amplitude modulated oscillation F 1 MHz f 1 kHz m 50 UT 28 3 mVrms If the...

Page 17: ...ing mode it is possible to trigger at any amplitude point of a signal edge even with very complex signal shapes by adjusting the LEVEL control Its adjusting range is directly dependent on the display...

Page 18: ...eringcanalsobeusefultodisplaysignalsbelowthe triggerthreshold lessthan0 5div Itisthereforeparticularly suitable for measuring small ripple voltages of mains line rectifiers or stray magnetic field in...

Page 19: ...iodes marked OVERSCAN which are located between the attenuators Should one LED illuminate without an input signal this means that the respective vertical positioning control has been improperly adjust...

Page 20: ...orizontal axis and with low values the slope will move towards the vertical axis Values of resistance from 20 to 4 7k can be approxi mately evaluated The determination of actual values will come with...

Page 21: ...n by 180 degrees round about the center point of the scope graticule In Circuit Tests Caution During in circuit tests make sure the circuit is dead No power from mains line or battery and no signal in...

Page 22: ...ort circuit Resistor 510 Junction B C Junction B E Mains transformer prim Capacitor33 F Junction E C FET Z diode below 7V Z diode beyond 7V Diode paralleled by 680 2 Diodes antiparallel Silicon diode...

Page 23: ...n 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 lineari...

Page 24: ...anneldisplaywiththe CHI IIbutton is unnecessary it is contained indirectly in the tests above stated input of the vertical amplifier e g using a x1 probe the displayed signal in the50mV div position v...

Page 25: ...splay should not shift horizontally during a change of the trigger coupling from AC to DC with a sine wave signal without DC offset If both vertical inputs are AC coupled to the same signal and both t...

Page 26: ...LDOFF knob Component Tester After pressing the COMP TESTER button a horizontal straight line has to appear immediately when theCOMP TESTER socket is open The length of this trace should be approx 8div...

Page 27: ...d from all voltage sources Normally the capacitors are discharged approx 6 seconds after switching off However with a defective instrument an interruption oftheloadisnotimpossible Therefore afterswitc...

Page 28: ...g Checktoseethatallcircuitboardconnections are making good contact and are not shorting to an adjacent circuit Especially inspect the connections between the PCBs to front chassis parts to CRT PCB to...

Page 29: ...ring TRIG EXT button depressed sync signal 0 3Vpp to 3Vpp to TRIG INP socket Line triggering TRIG selector switch to Select trigger coupling with TRIG selector switch Trigger frequency ranges AC 20Hz...

Page 30: ...nector horizontal deflection in X Y mode Y POS II Controls vertical position knob of channel II display Inoperative in X Y mode POWER Turns scope on and off pushbutton LED LED indicates operating cond...

Page 31: ...1 3 5 6 7 8 9 14 15 16 17 2 4 10 11 12 13 20 21 22 23 24 25 26 27 28 30 31 34 36 37 38 33 32 18 29 19 35...

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