Good Will Instrument GOS-6051 User manual

GOS-6051/6050/6031/6030 OSCILLOSCOPE
USER MANUAL
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CONTENTS PAGE
1. PRODUCT INTRODUCTION.................................................
1-1.Description……………………………………………….
1-2.Feature…………………………………………………....
1
1
2
2. TECHNICAL SPECIFICATIONS………………………… 4
3. PRECAUTIONS BEFORE OPERATION…….…………...
3-1.Unpacking the Oscilloscope……………….………….…
3-2.Checking the Line Voltage…………………..…………..
3-3.Environment……………………………………..………
3-4.Equipment Installation and Operation………………....
3-5.CRT Intensity……………………………………………
3-6.Withstanding Voltage of Input Terminals……………...
7
7
7
8
8
8
8
4. PANEL INTRODUCTION……………………..…………...
4-1.Front Panel……………………………………………….
4-2.Rear Panel……………………………………….……….
8
11
26
5. OPERATION METHOD………………………………...….
5-1.Readout Display……………………………………..…...
5-2.Connecting Input Signals..………………………………
5-3.Adjustment and Checks…………………………………
5-4.Function Check…..………………………………………
5-5.Basic Operation………….….…………………………....
5-6.Measurement Application……………………………….
28
28
30
31
33
35
44
6. MAINTENANCE……………………………………………
6-1.Fuse Replacement………………………………………..
6-2.Line Voltage Conversion……………………………..….
6-3.Cleaning………………………………………………….
46
46
46
47
7. BLOCK DIAGRAM………………………………………... 48
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SAFETY TERMS AND SYMBOLS
These terms may appear in this manual or on the product:
WARNING. Warning statements identify condition or
practices that could result in injury or loss of life.
CAUTION. Caution statements identify conditions or
practices that could result in damage to this product or
other property.
The following symbols may appear in this manual or on the product:
DANGER ATTENTION Protective Earth(ground)
High Voltage refer to Manual Conductor Terminal
Terminal

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FOR UNITED KINGDOM ONLY
NOTE: This lead/appliance must only be wired by competent persons
WARNING: THIS APPLIANCE MUST BE EARTHED
IMPORTANT: The wires in this lead are coloured in accordance with
the following code:
Green/ Yellow: Earth
Blue: Neutral
Brown: Live (Phase)
As the colours of the wires in main leads may not correspond with the
colours marking identified in your plug/appliance, proceed as follows:
The wire which is coloured Green & Yellow must be connected to the
Earth terminal marked with the letter E or by the earth symbol
or coloured Green or Green & Yellow.
The wire which is coloured Blue must be connected to the terminal
which is marked with the letter N or coloured Blue or Black.
The wire which is coloured Brown must be connected to the terminal
marked with the letter L or P or coloured Brown or Red.
If in doubt, consult the instructions provided with the equipment or
contact the supplier.
This cable/appliance should be protected by a suitably rated and
approved HBC mains fuse: refer to the rating information on the
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equipment and/or user instructions for details. As a guide, cable of
0.75mm2should be protected by a 3A or 5A fuse. Larger conductors
would normally require 13A types, depending on the connection
method used.
Any moulded mains connector that requires removal /replacement
must be destroyed by removal of any fuse & fuse carrier and disposed
of immediately, as a plug with bared wires is hazardous if a engaged
in live socket. Any re-wiring must be carried out in accordance with
the information detailed on this label.

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Declaration of Conformity
We
GOOD WILL INSTRUMENT CO., LTD.
No.7-1, Jhongsing Road, Tucheng City, Taipei County 236, Taiwan
GOOD WILL INSTRUMENT (SUZHOU) CO., LTD.
No.69 Lushan Road, Suzhou New District Jiangsu, China.
declares that the below mentioned product
GOS-6051/6050, GOS-6031/6030
are herewith confirmed to comply with the requirements set out in the Council Directive on
the Approximation of the Law of Member States relating to Electromagnetic Compatibility
(89/336/EEC, 92/31/EEC, 93/68/EEC) and Low Voltage Equipment Directive
(73/23/EEC, 93/68/EEC).
For the evaluation regarding the Electromagnetic Compatibility and Low Voltage
Equipment Directive, the following standards were applied:
◎EMC
EN 61326-1: Electrical equipment for measurement, control and laboratory use –– EMC
requirements (1997+A1: 1998)
Conducted and Radiated Emission
EN 55011: 1998 Group I class A
Electrostatic Discharge
IEC 61000-4-2: 1995
Current Harmonic
IEC 61000-3-2: 1995
Radiated Immunity
IEC 61000-4-3: 1995
Voltage Fluctuation
IEC 61000-3-3: 1994
Electrical Fast Transients
IEC 61000-4-4: 1995
------------------------- Surge Immunity
IEC 61000-4-5: 1995
------------------------- Conducted Susceptibility
IEC 61000-4-6: 1996
------------------------- Power Frequency Magnetic Field
IEC 61000-4-8: 1993
------------------------- Voltage Dips/ Interrupts
IEC 61000-4-11: 1994
◎Safety
Low Voltage Equipment Directive 73/23/EEC & amended by 93/68/EEC
Safety Requirements
IEC/EN 61010-1: 2001
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1.PRODUCT INTRODUCTION
1-1. Description
The GOS-6051/50/31/30 series are 50MHz/30MHz, two-channel, portable
oscilloscopes for general purpose use. A microprocessor-based operating system
controls most of the functions of the instrument, including cursor readout and
digitized panel setting. On-screen alphanumeric readout and cursor function for
voltage, time and frequency measurement provide extraordinary operational
convenience. It also has the function of auto measurement for frequency and
counter. Ten different user defined instrument settings can be saved and recalled
without restriction.
The vertical deflection system has two input channels. Each channel has 14 basic
deflection factors from 1mV to 20V per division. The horizontal deflection
system provides sweep time from 0.5s to 0.2μs per division. The trigger system
provides stable triggering over the full bandwidth of the vertical deflection
system.

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1-2.Features
Additionally, the oscilloscope offers several other features:
1) High intensity and internal graticule CRT
The oscilloscope employs a high intensity 6-inch retangular type cathode-
ray tube with red internal graticule. It displays clear readable traces even at
high sweep speeds. Internal graticule lines eliminate parallax-viewing error
between the trace and the graticule line.
2) Frequency Counter (GOS-6051/6031)
A built-in 6 digits frequency counter is accurate within the range of ±
0.01% measuring frequency between 1kHz to 30/50MHz and ±0.05%
measuring 50Hz to 1kHz.
3) ALT-MAG Function
The primary sweep waveform along with the magnified sweep waveform
can be displayed simultaneously using the ALT-MAG function. The
magnification ratio can be selected from among three stages of ×5, ×10, ×
20 for magnifying the displayed waveform in the center of the CRT.
4) Convenient VERT-MODE Triggering
The sync signal source is decided automatically when vertical axis mode is
switched. This means that you need not change the trigger source every
time you switch the VERT-MODE.
5) TV triggering
Exclusive TV sync separator circuit technology provides stable TV signal
measurements on fields, frames and lines.
6) Hold Off
The function allows the obtaining of stable synchronization for even
complex waveforms that are difficult to synchronized by adjusting the
trigger level alone.
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7) CH1 Signal Output
The CH1 signal output is obtained by branching the input signal in the
middle of the signal line. As the connector outputs the input signal at a
rate of 50mV/div, connecting a frequency counter makes it possible to
measure the frequency of a very low signal while observing its waveform.
8) Z-axis intensity modulation
For applying a blanking signal from an external source. The trace displayed
on the screen may be intensity-modulated where pulse signal or time-scale
marks are required.
9) LED indicator and buzzer alarm
The LED’s located in the front panel assist operation and indicated
additional information. Incorrect operation and the electrical end position
of control knobs are indicated by a warning beep.
10) SMD manufacturing technology
The instrument is built by using the most advanced SMD technology so as
to reduce the number of internal wiring and shorten the foil route on the pc
board. This will also greatly increase the high frequency performance and
the reliability of the product.
11) Compact size (275W×130H×370D)mm and front panel layout groups for easy-
to-use.

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2.TECHNICAL SPECIFICATIONS
Type
6-inch rectangular type with internal graticule;
0%, 10%, 90% and 100% markers.
8 x10 DIV (1 DIV = 1 cm)
Accelerating Potential Approx. 10kV (GOS-6051/6050),
2kV (GOS-6031/6030)
INTEN and FOCUS Front panel control.
Illumination Provided (GOS-6051/6031)
Trace Rotation Provided.
CRT
Z-axis Input Sensitivity: at least 5V
Polarity : positive going input decrease intensity
Usable frequency range: DC to 2MHz.
Max. input voltage: 30V (DC +AC peak) at 1kHz
or less.
Input Impedance: approx. 33kΩ(GOS-6051/6050)
47kΩ(GOS-6031/6030)
Sensitivity Accuracy 1mV~2mV/DIV ±5%, 5mV~20V/DIV ±3%, 14
calibrated steps in 1-2-5 sequence.
Vernier Vertical
Sensitivity
Continuously variable to 1/2.5 or less of panel
indicate value.
GOS-6051/6050 Bandwidth(-3dB) Rise Time
5mV~20V/DIV DC~50MHz Approx. 7ns
1mV~2mV/DIV DC~7MHz Approx. 50ns
GOS-6031/6030 Bandwidth(-3dB) Rise Time
5mV~20V/DIV DC~30MHz Approx. 11.7ns
Bandwidth(-3dB) and
Rise Time
1mV~2mV/DIV DC~7MHz Approx. 50ns
Maximum Input Voltage 400V (DC + AC peak) at 1kHz or less.
Input Coupling AC, DC, GND
Input Impedance Approx. 1MΩ±2% // approx. 25pF
Vertical Modes CH1, CH2, DUAL(CHOP/ALT), ADD, CH2 INV.
CHOP Frequency Approx. 250kHz.
VERTICAL
SYSTEM
Dynamic Range GOS-6051/6050: 6DIV at 50MHz,
GOS-6031/6030: 8DIV at 20MHz, 6DIV at 30MHz
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Sweep Time
0.2μs/DIV~0.5s/div, 20 steps selectable in 1-2-5
sequence, continuous variable control between steps
at least 1:2.5.
Accuracy ±3%, ±5% at ×5 and ×10 MAG, ±8% at ×20 MAG
Sweep Magnification ×5, ×10, ×20 MAG
Maximum Sweep Time
(at MAG)
GOS-6051/6050:20ns/DIV(10ns/DIV uncalibrated)
GOS-6031/6030:50ns/DIV(10ns/DIV~40ns/DIV
uncalibrated.
HORIZONTAL
SYSTEM
ALT-MAG Function Available.
Trigger Modes AUTO, NORM, TV
Trigger Source VERT-MODE, CH1, CH2, LINE, EXT.
Trigger Coupling AC, HFR, LFR, TV-V(-), TV-H(-).
Trigger Slope “+” or “- ” polarity.
GOS-6051/
GOS-6050
CH1,
CH2
VERT-
MODE EXT
20Hz~5MHz 0.5 DIV 2.0 DIV 200mV
5MHz~40MHz 1.5 DIV 3.0 DIV 800mV
40MHz~50MHz 2.0 DIV 3.5 DIV 1V
GOS-6031/
GOS-6030
CH1,
CH2
VERT-
MODE EXT
20Hz~2MHz 0.5 DIV 2.0 DIV 200mV
2MHz~20MHz 1.5 DIV 3.0 DIV 800mV
20MHz~30MHz 2.0 DIV 3.5 DIV 1V
Trigger Sensitivity
TV sync pulse more than 1 DIV (CH1, CH2, VERT-
MODE) or 200mV (EXT).
External Trigger Input
Input impedance: Approx. 1MΩ//25pF(AC
coupling)
Max. input voltage: 400V (DC + AC peak) at 1kHz.
TRIGGER
SYSTEM
Hold-off Time Variable.
Input X-axis : CH1, Y-axis : CH2
Sensitivity 1mV/DIV~20V/DIV.
Bandwidth X-axis: DC~500kHz (-3dB)
X-Y
OPERATION Phase Difference 3°or less from DC to 50kHz
CH1 Signal Output
Voltage : approx. 20mV/DIV (with 50Ω
terminal.)
Bandwidth: 50Hz to at least 5MHz.
OUTPUT
SIGNAL
Calibrator output Voltage : 0.5V±3%,
Frequency: approx. 1kHz, square wave.

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Panel Setting Display CH1/CH2 sensitivity, sweep time, trigger condition
Panel Setting Save &
Recall 10 sets.(GOS-6051/6031)
Cursor Measurement
(GOS-6051/6031)
Cursor Measurement Function: ΔV, ΔT, 1/ΔT.
Cursor Resolution: 1/25 DIV.
Effective Cursor Range: Vertical:±3 DIV,
Horizontal: ±4 DIV
CRT
READOUT
Frequency Counter
(GOS-6051/6031)
Display Digits: Max. 6-digits decimal.
Frequency Range: 50Hz~50MHz (GOS-6051)
50Hz~30MHz (GOS-6031)
Accuracy: ±0.05%: 50Hz~1kHz.
±0.01%: 1kHz~30/50MHz.
Measuring Sensitivity: The satisfied value of the
above-mentioned Trigger Sensitivity plus 1 DIV.
(measuring source selected from CH1 or CH2 as
synchronous signal source).
Voltage AC100V, 120V, 230V ±10% selectable.
Frequency 50Hz or 60Hz.
LINE POWER
REQUIREMENT Power Consumption Approx. 60VA, 50W(max).
Dimensions 275(W)×130(H)×370(D) mm.MECHANICAL
SPEC. Weights 8 kg
OPERATING
ENVIRONMENT
Indoor use
Altitude up to 2000 m
Ambient temperature :
To satisfy specifications : 10℃to 35℃( 50°F to 95°F )
Maximum operating ranges: 0℃to 40℃( 32°F to 104°F )
Relative humidity: 85% RH(max.) non condensing
Installation Category : II
Pollution degree 2
STORAGE
TEMPERATUR
E & HUMIDITY
-10°to 70℃, 70%RH(maximum)
ACCESSORIES
Power cord….............……….. 1
Instruction manual…………… 1
Probe (×1/×10)…………..….... 2
Measurement category I is for measurements performed on circuits not directly connected
to MAINS.
Measurement category II is for measurements performed on circuits directly connected to
the low voltage installation.
Measurement category III is for measurements performed in the building installation.
Measurement category IV is for measurements performed at the source of the low-voltage
installation.
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3.PRECAUTIONS BEFORE OPERATION
3-1.Unpacking the Oscilloscope
The product has been fully inspected and tested before shipping from the
factory. Upon receiving the instrument, please unpack and inspect it to check
if there is any damages caused during transportation. If any sign of damage is
found, notify the bearer and/or the dealer immediately.
3-2.Checking the Line Voltage
The oscilloscope can be applied any kind of line voltage shown in the table
below. Before connecting the power plug to an AC line outlet, make sure the
voltage selector of the rear panel is set to the correct position corresponding to
the line voltage. It might be damaged the instrument if connected to the wrong
AC line voltage.
WARNING. To avoid electrical shock the power cord protective
grounding conductor must be connected to ground.
When line voltages are changed, replace the required fuses shown as below:
Line voltage Range Fuse Line voltage Range Fuse
100V
120V
90-110V
108-132V T 1A250V 230V 207-250V T 0.4A250V
WARNING. To avoid personal injury, disconnect the power cord
before removing the fuse holder.

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3-3.Environment
The normal ambient temperature range of this instrument is from 0°to 40°C
(32°to 104°F). To operate the instrument over this specific temperature range
may cause damage to the circuits.
Do not use the instrument in a place where strong magnetic or electric field
exists as it may disturb the measurement.
3-4.Equipment Installation, and Operation
Ensure there is proper ventilation for the vents in the oscilloscope case. If the
equipment is used not according to the specification, the protection provided
by the equipment may be impaired.
3-5.CRT Intensity
To prevent permanent damage to the CRT phosphor, do not make the CRT
trace brighten excessively or leave the spot stay for an unreasonably long time.
3-6.Withstanding Voltages of Input Terminals
The withstanding voltages of the instrument input terminals and probe Input
terminals are shown in the following table. Do not apply voltages higher than
these limits.
Input terminal Maximum input voltage
CH1, CH2, inputs 400V (DC + AC peak)
EXT TRIG input 400V (DC + AC peak)
Probe inputs 600V (DC + AC peak)
Z AXIS input 30V (DC + AC peak)
CAUTION. To avoid damaging the instrument, do not apply
input voltages of the frequency over 1 kHz to the instrument.
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4. PANEL INTRODUCTION
After the instrument is switched on, all the important settings are displayed in
the readout. The LED’s located on the front panel assist operation and indicate
additional information. Incorrect operation and the electrical end positions of
control knobs are indicated by a warning beep.
All of the pushbuttons, VOLTS/DIV control knobs, TIME/DIV control knobs
are electronically selected, and their functions and settings can therefore be
stored.
The front panel is subdivided into four sections:
zDisplay controls
zVertical controls
zHorizontal controls
zTrigger controls

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Front panel of GOS-6031/6051
Front panel of GOS-6030/6050
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4-1.Front Panel
Display controls
The display controls adjust the on-screen appearance of the waveform and
provide a probe compensation signal source.
(1) POWER – Pushbutton
When switch on the oscilloscope to have all LEDs lighted and wait a few
seconds, the normal operation mode is present. Then the last settings
become activated and the LED indicates “ON” condition.
(2) TRACE ROTATION
The TRACE ROTATION is for aligning the horizontal trace in parallel with
graticule lines. This potentiometer can be adjusted with a small screwdriver.

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(3) INTEN—Control knob
The control knob is used for adjusting the traces intensity. Turning the knob
clockwise to increase the intensity while turning it counterclockwise to
decrease the intensity.
(4) FOCUS
The control knob effects both the trace and the readout sharply.
(5) CAL
The terminal provides a reference signal of 0.5Vp-p at 1kHz for probe
adjustment.
(6) Ground Socket—Banana Socket galvanically connected to safety earth
This socket can be used a reference potential connection for DC and low
frequency signal measurement purpose.
(7) TEXT/ILLUM—Control knob with a double function.
The pushbutton is for selecting the text readout intensity function or scale
illumination function, and indicates the letter “TEXT” or “ILLUM” in the
readout. Press the pushbutton for the following sequences:
“TEXT” — “ILLUM” — “TEXT”
The TEXT/ILLUM function are associated the VARIABLE(9) control knob.
Turning the knob clockwise to increase the text intensity or scale
illumination, while turning the knob counterclockwise to decrease it.
Pressing the knob to switch the TEXT/ILLUM on or off.
(8) CURSORS MEASUREMENT FUNCTION (GOS-6051/6031)
There are two pushbutton and associated the VARIABLE(9) control knob.
△V—△T—1/△T—OFF Pushbutton
When the pushbutton is pressed, the three measurement functions will be
selected in the sequence as follows:
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△V: Two horizontal cursors appear. The voltage between the two cursors
is calculated according to the setting of VOLTS/DIV, and displayed
with △V on the upper side of the CRT.
△T: Two vertical cursors appear. The time between the two cursors is
calculated according to the setting of TIME/DIV, and displayed with
△T on the upper side of the CRT.
1/△T: Two vertical cursors appear. The reciprocal of the time (frequency)
between the two cursors is calculated with 1/△T on the upper side of
the CRT.
C1—C2—TRK Pushbutton
The cursor 1, cursor 2 and tracking can be selected by this button. Pressing the
pushbutton to select the cursors in sequence as follows:
C1: Moves the cursor 1 on the CRT(▼or symbol is displayed)
C2: Moves the cursor 2 on the CRT(▼or symbol is displayed)
TRK: Simultaneously moves the cursor 1 and cursor 2 with the interval
between the two cursors unchanged (both symbol are displayed at the
two cursors.)
(9) VARIABLE—
Set the cursor position, TEXT/ILLUM, etc. by turning or pressing the
VARIABLE knob.
In the cursor mode, pressing the VARIABLE control knob to select the cursor
position between FINE and COARSE adjustment. When select FINE
adjustment by turning the VARIABLE, the cursor lines will move slowly. If
select COARSE adjustment, he cursor will move fast.
In TEXT/ILLUM mode, this control knob can be used to set the text intensity
or illumination. Please refer to TXT/ILLUM(7) for details.

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(10). ◄MEMO- 9 ►—SAVE/RECALL(GOS-6051/6031)
The instrument contains 10 non-volatile memories, which can be used by the
operator to save instrument setting and to recall them. It relates to all controls
which are electronically selected.
Press ◄or ►pushbutton to select the memory location. The readout then
indicates the letter “M” followed by a cipher between 0 and 9. Each time the
►pushbutton is briefly pressed the memory location cipher increases until
the number 9 is reached. The ◄pushbutton is similar but decreases the
memory location cipher until the number 0 is reached.
Pressing and holding SAVE for approx. 3 seconds to write the instrument
settings in the memory and indicate the associated readout information of
“ ◄─┘ ”.
To recall a front panel setup, select a memory location as described above.
Recall the settings by pressing and holding the RECALL pushbutton for
approx. 3 seconds, the readout then indicates the associated readout
information of “ ┌─► ”.
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Vertical controls
The vertical controls select the displayed signals and control the amplitude
characteristics.
(11) CH1—Pushbutton
(12) CH2—Pushbutton
Pressing briefly the CH1 (CH2) button to set the channel 1 (channel 2) of
the instrument on, the deflection coefficient will be displayed in the
readout indicating the current conditions.
(13) CH1 POSITION—Control knob
(14) CH2 POSITION—Control knob
The vertical trace position of channel 1 (channel 2) can be set with the
control knob.
In X-Y mode, CH2 POSITION control knob is used for the Y deflection.

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(15) ALT/CHOP
The pushbutton has two functions, which are required and available only
when both channels are active.
ALT—Displays in the readout, indicates alternate channel switching. After
each time base sweeps the instrument internally, switches over from
channel 1 and channel 2 and vice versa.
CHOP—Indicates chopper
The channel switching occurs constantly between channel 1 and channel 2
during each sweep.
(16) ADD-INV—Pushbutton with double functions.
ADD– Displays the “+” symbol in the readout, indicates additional mode.
Whether the algebraic sum (addition) or the difference (subtraction) of both
input signals is displayed, depends on the phase relationship and the INV
setting. As a result, both signals are displayed as one signal. For correct
measurements, the deflection coefficients for both channels must be equal.
INV—Pressing and holding the pushbutton to set the channel 2 invert
function on or off. The invert on condition is indicated by the “ ” symbol
in the readout. The invert function causes the signal display of channel 2 to
be inverted by 180o.
(17)CH1 VOLTS/DIV
(18)CH2 VOLTS/DIV– Control knob for channel 1/channel 2 has double
functions.
Turning the knob clockwise to increase the sensitivity in 1-2-5 sequence and
turning it in the opposite direction (CCW) to decrease. The available range is
from 1mV/div up to 20V/div. The knob is automatically switched inactive if
the related channel is switched off.
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The deflection coefficients and additional information regarding the active
channels are displayed in the readout.
VAR
Pressing the VOLTS/DIV control knob to select the VOLTS/DIV function
between attenuator and vernier (variable). The current setting is displayed
by the “>” symbol in the readout.
After switching on the VAR, turn the VOLTS/DIV control knob
counterclockwise to reduce the signal height, and the deflection coefficient
becomes uncalibrated.
(19)CH1 AC/DC
(20)CH2 AC/DC
Pressing the pushbutton briefly to switch over from AC (~ symbol) to DC
(= symbol) input coupling. The setting is displayed in the readout with the
deflection coefficient.
(21)CH1 GND– P×10
(22)CH2 GND – P×10 –Pushbutton of two functions.
GND
Each time when the pushbutton is pressed briefly, the input of the vertical
amplifier is grounded. It is displayed in the readout as an earth (ground)
symbol “ ”.
P×10
Pressing and holding the pushbutton to select the indicated deflection
coefficient of the channel displayed in the readout between 1:1 and 10:1.
The probe factor of 10:1 is displayed in the readout with the probe symbol
“P×10” in front of channel indication. When proceed cursor voltage
measurement, the probe factor will be automatically included. The symbol
must not be activated unless a 10:1 attenuator probes are used.

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(23)CH1-X—Input BNC socket
This BNC socket is the signal input for channel 1. In X-Y mode, signals at
this input are used for the X deflection. The outer (ground) connection is
galvanically connected to the instrument ground and consequently to the
safety earth contact of the line/mains plug.
(24)CH2-Y—Input BNC socket
This BNC socket is the signal input for channel 2. In X-Y mode, signals at
this input are used for the Y deflection. The outer (ground) connection is
galvanically connected to the instrument ground and consequently to the
safety earth contact of the line/mains plug.
Horizontal controls:
The horizontal controls select the time base operation mode and adjust the horizontal
scale, position and magnification of the signal.
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(25)H POSITION
The control knob enables a horizontal position shift of the signals. In
combination with MAG the function makes it possible to shift any part of
the signal on the screen.
In X-Y mode, the control knob are used for the X deflection.
(26)TIME/DIV-VAR– Control knobs
Turning the knob clockwise to reduce the deflection coefficient in a 1-2-5
sequence and turning it in the opposite direction (CCW) to increase. The
time coefficient(s) will be displayed in the readout.
The time deflection coefficients between 0.5s/div and 0.2μs/div can be
chosen in 1-2-5 sequence, if the MAG function is not activated.
VAR
Pressing the pushbutton to select the TIME/DIV control knob function
between time base switch and vernier (variable). After switching on the
VAR, the time deflection coefficient is still calibrated until further
adjustments are made. Turn the TIME/DIV control knob counter clockwise
to increase the time deflection coefficient (reduce the deflection speed) and
the deflection coefficient becomes uncalibrated. The current setting is
displayed by the “>” symbol in the readout.
(27)X-Y
Pressing the pushbutton when using the instrument as an X-Y oscilloscope.
The time deflection coefficient is replaced by the “X-Y” symbol in the
readout.
In this mode, the X (horizontal) signal is connected to the input of CH1;
the Y (vertical) signal is applied to the input of CH2 and has a deflection
range from less than 1mV to 20V/div at a reduced band-width of 500kHz.

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(28)×1/MAG
Pressing the pushbutton the select the sweep time between ×1 (normal)
and MAG (magnify). If the MAG function, the signal display will be
expanded and consequently only a part of the signal curve is visible. The
interesting part of the signal can be made visible with the aid of the H
POSITION control.
(29)MAG FUNCTION
×5-×10-×20 MAG
When MAG has been done, the displayed waveform will be expanded to
the right and left with the center of the CRT. The magnification ratio can
be selected from among three stage of ×5-×10-×20 MAG by pressing this
pushbutton.
ALT MAG
Pressing the pushbutton, the primary sweep waveform along with the
magnified sweep waveform. The magnified can be displayed
simultaneously using the ALT-MAG function. The magnified sweep
waveform appears 3 divisions below the primary sweep waveform.
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Trigger controls
The trigger controls determine the sweep start timing for both signal.
(30) ATO/NML – Pushbutton and indicator LEDs.
Pressing the pushbutton to select auto or normal trigger mode. The actual
setting is indicated by a LED.
Each time when the pushbutton is pressed the trigger mode changes in the
sequence:
ATO—NML—ATO
ATO (Auto)
Select the automatical mode, the sweep free-runs will display a baseline
trace when there is no trigger signal. The setting of triggering level changed
only when the TRIGGER LEVEL control is adjusted to a new level setting.
NML (Normal)
Select the normal mode, the input signal will trigger the sweep when the
TRIGGER LEVEL control is set within the peak-to-peak limits of an
adequate trigger signal. When the sweep is not triggered, no baseline trace

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will be displayed.
Use this mode when effecting synchronization to a very low frequency
signal (25Hz or less).
(31)SOURCE—Pushbutton
Pressing the pushbutton to select the trigger signal source. The actual
setting is indicated by the readout (“SOURCE”, slope, coupling).
Each time when the pushbutton is pressed, the trigger source change in the
sequence:
VERT—CH1—CH2—LINE—EXT—VERT
VERT (Vertical Mode)
For observing two waveforms, the sync signal changes alternately
corresponding to the signals on CH1 and CH2 to trigger the signal.
CH1
The signal applied to the channel 1 input connector is the source of the
trigger signal.
CH2
The signal applied to the channel 2 input connector is the source of the
trigger signal.
LINE
The triggering signal is obtained from a sample of the AC power source
waveform. The trigger source is useful when the displayed waveform
frequency is time related to the AC power source frequency.
EXT
The external signal applied through the EXT input connector is used for
the external triggering source signal.
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(32)TV—Pushbutton for video sync signal selection
Separate the video sync signal from the composite waveform and direct it
to the triggering circuit. The horizontal or vertical sync signals are
selected by TV pushbutton. The current setting is displayed in the
readout under item (source, video polarity, “TVV or TVH”). Each time
when the pushbutton is pressed, the video sync signal is displayed in the
sequences as follows:
TV-V—TV-H—OFF—TV-V
TV-V
Start the main trace at the beginning of a video signal field. The polarity
must match the composite sync polarity (i.e, “ ” for negative sync) to
obtain TV field triggering on the vertical sync pulse.
TV-H
Start the main trace at the beginning of a video signal line. The polarity
must match the composite sync polarity to obtain TV line triggering on the
horizontal sync pulse.
(33)SLOPE—Pushbutton for the triggering slope.
Briefly pressing the pushbutton to select the slope of the signal which is
used for triggering the time base generator. Each time when the pushbutton
is briefly pressed, the slope direction will switch from falling edge to
rising edge, and vice versa.
The current setting is displayed in the readout under item “source, SLOPE,
coupling”.
If in the TV trigger mode, it is synchronized only when the sync signal is
negative. A “ ” symbol is displayed in the readout.

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(34)COUPLING—
Pressing the pushbutton to select the trigger coupling. The actual setting is
indicated by the readout ( source, slope “COUPLING”).
Each time when the COUPLING pushbutton is pressed the trigger coupling
changes in the sequence:
AC—HFR—LFR—AC
AC
Attenuates trigger signal frequency components below 20Hz and blocks the
DC component of the signal.
AC coupling is useful for triggering on AC waveforms that have a large DC
offset.
HFR (High Frequency Reject)
Attenuates high-frequency triggering signal components above 50kHz. HFR
coupling is useful for providing a stable display of low-frequency
components of complex waveforms and eliminates high-frequency
interference from the trigger signal.
LFR (Low Frequency Reject)
Attenuates low-frequency triggering signal components below 30kHz and
blocks the DC component of the trigger signal.
LFR coupling is useful for producing stable triggering on the high-
frequency components of complex waveforms and rejecting low-frequency
interference or power supply hum from the trigger signal.
(35)TRIGGER LEVEL—Control knob with TRG LED
Turning the control knob causes a different trigger input setting (voltage),
and set to a suitable position for the starting of triggered sweep of the
waveform. When rotate clockwise the control knob, the trigger point moves
toward the positive peak of the trigger signal and rotate it counterclockwise
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to move the trigger point toward the negative peak of the trigger signal.
When the setting (voltage) value is out of the changing portion of the
observation waveform, the synchronization sweep stops.
TRG LED
The TRG LED is lit if the triggering conditions are met. Whether the LED
flashes or is lit constantly depends on the frequency of the trigger signal.
(36)HOLD-OFF—Control knob
Used when the signal waveform is complex and stable triggering cannot be
attained with the TRIGGER LEVEL(35) knob alone, rotate this control
knob to adjust hold-off time(trigger inhibit period beyond sweep duration).
When control is rotated fully clockwise, the hold-off period is at MINimum
(normal). The hold-off period increases progressively with
counterclockwise rotation.
(37)TRIG EXT—This BNC socket is the external trigger signal input.
Pressing the TRIG. SOURCE (31) pushbutton until the information of
“EXT, slope, coupling” is shown up in the readout switches the input on.
The outer (ground) connection is galvanically connected to the instrument
ground and consequently to the safety earth contact of the line/mains plug.
The maximum input voltages of the input terminal are shown in the section
of 3-6. “Withstanding voltage of Input terminals”. Do not apply voltage
higher than the limit.

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4-2.Rear Panel
The rear panel provides input power and additional signal connections.
(38)Line voltage selector and input fuse holder—Select power source and
contain the primary power fuse
The fuse rating is shown in the section of 3-2 Checking the line voltage.
(39)AC power input connector
Connect the AC power cord to the power supply of instrument, the power
cord protective-ground connection is connected to the exposed metal part
of the instrument. The power cord must be connected to a proper grounded
source for electrical-shock protection.
(40)CH1 Output—BNC socket
This output may be used to connect to a frequency counter or other
instrument.
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(41)Z-Axis Input—BNC socket
Connect external signals to the Z-axis amplifier for intensity modulating
the CRT display. This terminal is DC-coupled. The intensity is lowered by
a positive signal, while it is increased by a negative signal.

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5. OPERATION METHOD
This section contains basic operation information and techniques that should be
considered before proceeding any measurement. As for the location and
function of instrument controls, connectors, and indicators, refer to the
“Instruction of Front Panel and Rear Panel” of this manual.
5-1.Readout Display
The CRT readout display indicates how to set up the instrument controls. No
physical marking shown on the rotating switches indicates the control setting.
A key to the location and type of readout information displayed is illustrated in
figure 5-1:
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Figure 5-1 Readout Layout

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5-2.Connecting Input Signals
Grounding
The most reliable signal measurements are made when the oscilloscope and
the unit under test are connected by a common reference (ground lead) in
addition to the signal lead or probe. The ground lead of the probe provides the
best grounding method for signal interconnection and ensures the maximum
amount of signal-lead shielding in the probe cable. A separate ground lead
(with a banana plug) can also be connected from the unit under test to the
oscilloscope ground jack on the front panel.
Probes
A probe provides the most convenient way to connect an input signal to the
oscilloscope. The standard ×1/×10 probes supplied to the oscilloscope are
shielded against electromagnetic interference and have a high input impedance
for low circuit loading.
CAUTION. To get the best waveform precisely, keep
probe ground and signal leads as short as possible.
Misadjust probe compensation can cause measurement error. Check and adjust
probe compensation whenever a probe is moved to a different channel or
oscilloscope. As for the probe compensation adjustment procedure, refer to the
“Probe Compensation”.
Coaxial Cables
Signal input cable can greatly affect the accuracy of a displayed waveform. To
maintain original frequency characteristics of the input signal, use only high-
quality, low-loss coaxial cables. Coaxial cables must be terminated at both
ends in their characteristic impedance to prevent signal reflections within the
cable. Use suitable impedance-matching devices.
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5-3.Adjustments and checks
Trace Rotation Adjustment
Normally, when the trace is in parallel with the center horizontal graticule line,
there will be no need to adjust the TRACE ROTATION. If necessary, adjust
the TRACE ROTATION to make the baseline trace parallel to the center
horizontal graticule line by using a small straight-blade screwdriver or
alignment tool.
Probe Compensation
To minimize the distortion of measured waveforms, check the compensation of
your probes before using them. The probe compensation should be checked
periodically whenever the probes are moved to different input channels.
1. Install the probes onto the oscilloscope (Press the BNC connector onto the
channel input and rotate the connector to lock it into place).
2. Set the probe slide switches to the ×10 position.
3. Briefly pressing the CH1/CH2 button to set the oscilloscope to channel 1
and channel 2.
4. Pressing and holding the P×10 button to set the indicated deflection
coefficient of the channel displayed in the readout as a symbol “P10”.
5. Attach the probe tips to the CAL connection in the front of the oscilloscope.
6. Set the oscilloscope controls to display both channels:
VERTICAL: VOLTS/DIV 0.2V
COUPLING DC
ALT/CHOP CHOP
HORIZONTAL:
TIME/DIV 0.5ms
TRIGGER: MODE ATO
SOURCE VERT
COUPLING AC
SLOPE
7. Observe the displayed waveform and compare them with the waveforms

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shown in figure 5-2. If either probe needs to be adjusted, proceed the step 8.
If either probe does not need to be adjusted, proceed the “Function Check”.
Figure 5-2 Typical Compensation Waveform
8.Adjust the probe by using a small insulated screwdriver. Slowly rotate the
adjustment control until the probe is properly compensated.
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5-4.Function Check
When you start to check the operation of your oscilloscope, proceed the
following instruction:
1. Install the ×10 probes onto CH1 and CH2 inputs.
2. Connect the probe tips to the CAL test point of the oscilloscope.
3. Set the oscilloscope controls to display both channels:
VERTICAL: VOLTS/DIV 0.2V
COUPLING DC
ALT/CHOP CHOP
HORIZONTAL:
TIME/DIV 0.5ms
TRIGGER: MODE ATO
SOURCE VERT
COUPLING AC
SLOPE
The figure 5-3 below illustrates a satisfactory display. The waveform should
be approximately 0.5Vp-p at a frequency of 1kHz that confirms the vertical
and horizontal deflection function of the oscilloscope.
Figure 5-3

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4. Set both CH1 and CH2 COUPLING to GND.
5.Use the CH1 and CH2 POSITION controls to align both traces on the center
graticule.
6. Open the CH2 INV by pressing and holding the pushbutton.
7. Set to the ADD mode by pressing the ADD pushbutton briefly.
8. Set both CH1 and CH2 COUPLING to DC.
9.The figure 5-4 below shows a satisfactory display. The display will show a
flat trace located on the center gracticule that confirms the channel balance
and ADD offset function.
Figure 5-4 ADD mode
10. Turn off the ADD mode by pressing the ADD pushbutton briefly.
11. Turn off the CH2 INV by pressing and holding the pushbutton.
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5-5.Basic Operation
Displaying CH1 or CH2
To display the signal from a signal channel, pressing briefly the CH1 or CH2
pushbutton to set the oscilloscope to channel 1 or channel 2.
Displaying CH1 and CH2
To display both signals at the same time, proceed the following steps:
1.Set the CH1 and CH2 on. The figure 5-5 below shows two synchronous
waveforms in the both modes.
2.Adjust the CH1 or CH2 POSITION control to position the two waveforms.
3.Set the ALT/CHOP button to CHOP mode if the waveforms are flickering.
Figure 5-5 Both typical waveforms