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.