OSCILLOSCOPE
INSTRUCTION MANUAL
1.GENERAL
The oscilloscope is a dual – channel oscilloscope maximum Sensitivity
5mV/DIV.and maximum sweep time 5nsec/DIV. The oscilloscope
employs a 6 - inch rectangular type cathode - ray tube with internal
graticule. The instrument features a P – P AUTO trigger and an ALT
TRIG. The P-P AUTO trigger level function sets a variable trigger level
range according to the trigger signal amplitude to facilitate signal
synchronization .The ALT TRIG function displays two asynchronous
signal in stable. The oscilloscope is sturdy , easy to operate , and exhibits
a high operation reliability. It is incorporated with the various convenient
features and excellent functions , making itself an ideal instrument for diversified types of research and development work of electronic devices
and equipment, it can also be efficiently used for production lines and for
maintenance and service.
2.SPECIFICATION
2.1 Vertical Axis
Item
Specification
Sensitivity
5mV/DIV on 1-2-5 sequence 10 ranges
Accuracy
±3% or better
Vertical Sensitivity
TO 1:2.5 or less
Rise Time
17.5ns
Bandwidth
DC 0~50MHz AC 10Hz~20MHz
Input Impedance
1MΩ±3%,25pF±5pF
10:1 Probe: 10MΩ±5%.16pF±2pF
Maximum Input Voltage
400V(DC+AC peak)
Operation Mode
CHI, CHI, ALT, CHOP, ADD
2.2triggering
Item
Specification
Trigger Sensitivity
INT:DC-50MHz 1.0DIV
EXT:DC-50MHz 0.3DIV
AUTO Triggering
EXT Triggering
50Hz or over
Input Impedance
Maximum External
Trigger Voltage
Triggering Source
INT Triggering Source
Triggering Mode
1MΩ,20pF
160V(DC+AC peak)
INT,EXT,LINE
CH1,VERT MODE, CH2
NORM,AUTO,TV,P-P,AUTO
2.3 Horizontal Axis
Item
Sweep Rate
Specification
0.5s/DIV-0.2us/DIV(2Hz/DIV-5Hz/DIV)
20 steps in 1-2-5 sequence(4320/620c)
±3%
Accuracy
Sweep Time Control
To 1:2.5 or slower
Sweep Magnification
10 time(extend sweep rate up to 20nS/DIV
error±8%)4320/620C
2.4 X-Y Mode
Item
Sensitivity
Accuracy
Specification
Same as Vertical Deflection System
±5%
Bandwidth
DC-1MHz(-3dB)
Phase Shift
Less than 3º at DC-50KHz
2.5 Z Axis
Item
Sensitivity
Specification
(Trace becomes brightness with negative input)
Bandwidth
DC-1MHz
Input width
10KΩ
Allowable Input Voltage
50V(DC+AC peak)
2.6 Calibration Voltage
Item
Specification
Waveform
Square Wave
Output Voltage
0.5V±2%
Frequency
1KHz±2%
2.7 CRT
Item
Specification
Effective Size
8x10 DIV 1DIV =10mm
Acceleration Voltage
Approx .2KV
Phosphor
P 31
2.8 Power Requirements
Item
Specification
Voltage
110V:100V-120V
220V:220V-240V
Frequency
50Hz or 60Hz
Power Consumption
40W
2.9 Mechanical Specification
Item
Dimensions
Specification
310W x 130H x 418D(mm)
Weight
Approx.6.5Kg
2.9 Mechanical Specification
Item
Specification
Ambient Temperatures
Operating: 0ºC to 40 ºC
Storage:-40 ºC to 60 ºC
Humidity
Operating:90% RH(40 ºC)
Storage: 90% RH(50 ºC)
Altitude
Operating:
to 5000m
Non-operation: to 15000m
*The specifications are subject to change without notice
Front Panel
Model:620C
1MΩ 25PF
≤400VPK
X10
X1
V
S
mS
mV
X-Y
uS
-
V
+
+
-
1MΩ 25PF
≤400VPK
mV
1MΩ 20PF
≤400VPK
3.OPERATION METHOD
3.1Front Panel and Rear Panel
NO
1
Item
INTEN
Function
Brightness of the spot control
2
3
Focus
TRACE
ROTATION
Focus Control
Semi-fixed potentiometer of aligning the horizontal trace
in parallel with graticule lines.
4
POWER
INDICATO
R
POWER
Square wave
6
7.8.
9.
CAL
POSITION
VERT
MODE
10
11.12.
13.14.
CH2 INV
VOLT/DIV
VARIABLE
15.16.
AC-DC-GN
D
CH1(X),
CH2(Y)
Calibration signal output terminal 0.5Vp-p,approximately 1KHz.
CH1 and CH2 Vertical position control, pull up×5
Selects the operation mode of the vertical axis.
CH1:CH1 Signal displayed only.
CH2:CH2 Signal displayed only.
ALT:Dual-channel operation with CH1 and CH2 sweep alternately.
CHOP:The operation between channels chopped at
frequency of aproximately 500KHz of displayed channels .
Suitable for observation with slow sweep speeds.
ADD:For measurement of algebraic sum or difference of CH1
and CH2 PULL INVERT switch.
Keep down to invert the polarity of CH2
Select the vertical axis sensitivity.
Fine adjustment of sensitivity,with a factor of 1/3 or Lower of
the panel-indicated value.
Switch for selecting connection mode between input signal and
Vertical amplifier.
Vertical input terminal of CH1or CH2, In X-Y operation,
this terminal becomes X-axis or Y-axis input.
5
17.18.
19.
20.
POSITION
LEVEL
21.
22.
SLOPE
TRIG
MODE
Power on indication Power switch.
Positions the display horizontally.
It si for displaying a synchronized stationary waveform and
setting a start point for the waveform.
Selects the triggering slope.
NORM:When no triggering signal is applied,sweep is in a
ready state and the trace is blanked out .Trigger level range
is obtained by adjusting TRIG LEVEL control.
AUTO:when no triggering signal is applied or when triggering
signal frequency is more than 50Hz,sweep runs in the free run mode.
TV:The trigger circuit is connected to the TV Sync separator circuit and
the sweeps are synchronized with the TV-V signal .
P-P AUTO:auto matically operates trigger action.It can display a
synchronized stationaly waveform without adjusting TRIG LEVEL
control.
23.
TRIGID
The LED turns on .signal is triggered
24
25
26
DEC/DIV
VARIABLE
INT TRIG
SOURCE
TRIG
SOURCE
GND
Selects the sweep time
Vernier control of sweep time.
Selects the internal triggering source signal (CH1,CH2 or ALT).Allup
LINE
Selects the triggering source signal (INT,,EXT).
27
28
29
30.
31
32
33
34
35
36.
37
Ground terminal of oscilloscope mainframe.
Input terminal for extermal triggering sigmal.
EXT TRIG
CH1 vertical position control . Keep down for X-Y
operation(CH1-X,CH2-Y).
CH1-X
X-Y operation(CH1-X,CH2-Y).
X10
Keep down increases the displayed sweep rate by a factor of 10.
SEP ALT
Keep down operation with X1 and X10 signals sweep alternately.
TRAC SEP When the SEP ALT knov is keep down,with position the X10 signals.
HOLD OFF With operation complicated signals.
X
AXIS Input terminal for external intensity modulation signal.
INPUT
ACPOWER Inlet for detachabll AC power cord .
RECEPTAC Fuse rating:Time lag:110V-T1A/250V 220V-T0.5A/250V
LE
AND
FUSE
BW 50MHz Keep down with bandwidth 50MHz
3.3 operating methods
3.3.1 Check the Line Voltage
Betore connecting the power cord to an AC line outlet, check that the AC line
voltage selector plag on the rear panel of the instrument is correctly set for the AC line
voltage.
3.3.2 Basic operation
(1)Set the switch an d controls of the front panel as shown below:
*INTEN(1) to mid-position
*FOCUS(3) to mid-position
*POSITION(8)(9)(29) to mid-position,pushed in
*VERT MODE (10) in CH1 position
*VOLT/DIV(11)(12) to 2mv/DIV
*VARIABLE (13)(14)to CAL
*AC-DC-GND(15)(16) in AC
*SEC/DIV(26)to 50ns/DIV
*TRIG MODE(27) to P-PAUTO
*SLOPE(23) in+
*TRIG SOURCE (21) in CH1
(2)Turn the power switch on and make sure that the power pilot LED is lit. In about
20 seconds , a trace will appear on the CRT screen. Adjust the trace to an appro priate
brigtness and to the sharpest image with the INTEN control and FOVUS, ASTIG
controls. Align the trace with the horizontal center line of graticule by adhusting the
CH1 POSITION control and TRACE ROTATION control
(3)Connect the probe (inthe10:1 division ratio ,supplied)to the CH1 INPUT
terminal,and apply the 0.5V CAL signal to the probe tip.
(4)Adjust the FOCUS control until the sharpest trace image bccomes
available,Awaveform as shown in Fig 3-1.
(5)Single-channel operation with CH2 also can be made in a similar manner.
3.3.3 Brightness control
Adjust the INTEN control for comfortable view of traces.
3.3.4 Vertical Axis Operation
(1)Dual-channel Operation
When in the ALT mode, one channel is displayed for an entire sweep then the next
channel is displayed for an entire sweep.
When in the CHOP mode,the channel signals are chopped in sequence at a rate of
about 2μs(500KHz).Dual-channels traces are simultancously displayed in a
time-slicing method .This mode is used primarily for display of low frequency
signals at low sweep speeds.
(2)ADD Operation
Set the VERT MODE switch in the ADD position the signals of CH1 and CH2 can be
added as an algebraic sum on the screen.
When the CH2 INV knob is keep down the signals of CH1 and CH2 become the
difference between them on the screen.
(3)X-Y OPERATION
When the CH1-X knob is keep down (CH1-X,CH2-Y)the oscilloscope operates as an
X-Y xcope with the CH1 signal for the X-axis and the CH2 signal for the Y-axis.The
bandwidth of the X-axis becomes DC to 1MHz (-3dB)
(4)INPUT COUPLING
DC:de coupling ,all signal are directly connected to attenuator.
GNG:input signal si switched off and attenuator is grounded.
AC:blocks de signal component allowing only AC signal to pass into attenuator.
3.3.5 Triggring
(1)Function of SOURCE switch
To display a stationary pattern on the CRT scree, the displayed signal itself or a trigger signal
which has a time relationship with the displayed signal is required to be applied to the trigger
circuit. The SOURCE switch selects such a trigger source
LINE:The AC jpower line frequencysignal si used as the trigger signal .This method is effective
when the measured signal has arelationshi with the AC line frequency,especially for measurements
of low level AC noise of audio circuits,thyristor circuits,etc
EXT:The sweep is triggered with an external signal signal applied to the extemal trigger input
terminal.
EXT:The sweep is triggered with an external signal signal applied to the external trigger input
terminal.
An external sigmal which has a periodic relationship with respect to the meas ured signal is
used.Since the measured dignal (vertical input signal) is not used as the trigger signal,the
waveform display can be done independent of the measured signal.
INR:Internal triggering source,includes CH1,CH2,and VERT MODE.
(2)Fuction of INT TRIG SOURCE switch
CH1:The signal applied to the input terminal of CH1 is picked off from respective preamplifier in
ouder to be used as CH1 Trigger signal.
CH2:The signal applied to the input rerminal of CH2 is picked off from respective preamplifier in
ouder to be used as CH1 Trigger signal.
This CH1 or CH2 trigger method is used most commonly.The signal applied to the vertical input
terminal (the measured signal)si branched off from a point in the amplifier circuit and is fed to the
trigger circuit through the INT TRIG SLURCE switch .Since the trigger signal is the measured
signal itself,a very stable waveform can be readily displayed on the CRT screen.
During the CHOP or ADD operation, either the CH1 or CH2 must be selected as the triggering
source signal.
VERT MODE:During the CH1 or CH2 operation, the signal of the CH1 or CH2 is automatically
use as the triggering source signal. During the ALT operation,ALT trigger to synchronize two
asynchronous signals.
3.3.6 Horizontal Axis Operation
(1)Time Base
The maximum sweep speed is 0.2μs/div .Twenty positions ranging in 1-2-5sequence . The sweep
time can be mad slower by a factor of 2.5 or more of the panel-indicated balue. The
panel-indicated value are calibrated with vernier control knob set in CAL position.
When a certain position of the displayed waveform is meeded to be expanded timewise ,a faster
sweep speed may be used. Howerer,if the required fortiom is far away from the starting point of
the sweep, the required portion may run off the CRT screen. In such a case,keep down(set in the
×10 MAG state)the X10 knob. When this is done, the displayed waveform is expanded by
10 times to right or left with the center of screen at the center of expansion.
(2)Tiggering Mode
NORE:When no triggering signal applied,sweep is in a ready state and the trace is
blanked out.Used primarily for obseruation of signals of 20Hz or lower
AUTO:When no triggering signal si applied or when triggering signal frequency is more
the 20Hz ,sweep runs in the free run mode.
TV:The trigger circuit is connected to the TV sync separator circuit and the sweeps are
synchronized with the TV signal at a rate selected by the SEC/DEV switch/
P-P AUTO:Variable range of triggering level is set automatically depend on trigger signal
level.
(3)Function of SLOP switch
This switch selects the slppe(polarity )of the triggering signal.
Pull up the switch to be se in the "+"state, triggering of signal increase(i.e.nega-tive
direction)..
Push down the switch to be set in the "-"setate triggering occurs as the triggering signal
crosses the triggering level in the directiionof signal decrease(i.e.negative direction)
(4)Function of TRIG LEVEL
Used to select a level within signal peak range from which the sweep can be triggered at a
proper input signal starting edge.
The ttigger level changes tin the positive direction(upwark)as the control knob is tured
clocwise and it changes in the negative direction(downward)as the knob is turned counter
clockwise.
When the sweep is triggered,the TRIG'D turn on.
3.3.7 Adjustment of Probe
When the probe is used in×1 position it does not require frequency compensation
adjustment but in×10 position the probe must be properly frequency compensation
adjustment before used.Procedure of adjustment is indicated and shown below.
Connect the probe BNC to the INPUT terminal of CH1 or CH2,and set
VOLTS/DIV
switch at 10mV. Connect the probe tip to the calibration voltage output terminal and adjust
the COMPENSATOR control with an insulated screw driver so that ideal waveform as
illustrated below is obtained.