Subject to change without notice
29
Switching on and initial setting
Connect instrument to power outlet, depress red
POWER
button. LED indicates operating condition.
Case, chassis and all measuring terminals are connected to the safety earth conductor (Safety Class
I).
Do not depress any further button.
TRIG.
selector switch to
AC
.
AT/NORM.
button released,
CH.I
input coupling switch to
GD
, set
TIME/DIV.
switch to 50µs/div.
Adjust
INTENS.
control for average brightness.
Center trace on screen using
X-POS.
and
Y-POS.I
controls. Then focus trace using
FOCUS
control.
Vertical amplifier mode
Channel I: All buttons in the Y section in out position.
Channel II:
CHI/II
button depressed.
Channel I and II:
DUAL
button depressed. Alternate channel switching:
CHOP.
(
ADD
) button in out position.
Signals <1kHz or time coefficient
≥
1ms/div:
DUAL
and
CHOP.
buttons depressed.
Channel I+II or –I–II (sum): depress only
ADD
button.
Channel –I+II or +I–II (difference): depress
ADD
and the corresponding
INVERT
button.
Triggering mode
Select trigger mode with
AT/NORM.
button:
AT
= Automatic Triggering
<20
Hz to 80MHz (out position).
NORM.
= Normal Triggering (depressed).
Trigger edge direction: select slope with
SLOPE (±)
button.
Internal triggering: select channel with
TRIG. I/II (CH. I/II)
button.
Alternating triggering (internal):
ALT.
pushbutton depressed,
CHOP
. button in the out position.
External triggering:
TRIG. EXT.
button depressed; sync signal (0.3V
pp
to 3V
pp
) to
TRIG. INP.
socket.
Line triggering:
TRIG.
selector switch to
~
.
Select trigger coupling with
TRIG
. selector switch. Trigger frequency ranges:
AC
:
<2
0Hz to 100MHz;
DC
: DC to 100MHz;
LF
: DC to 1.5kHz.
TV
: Composite video signal with line or horizontal frequency.
TIME/DIV. 0.2s/div. - 0.2ms/div.
= field frequency
TIME/DIV. 0.1ms/div. - 0.1µs/div.
= line frequency
Select edge direction with
SLOPE (±)
button (sync. pulse above +, below –).
Pay attention to trigger indicator:
TR
LED above the
TRIG.
selector switch.
Measurements
Apply test signal to the vertical input connectors of
CH I
and/or
CH II
.
Before use, calibrate attenuator probe with built-in square wave generator
CAL
.
Switch input coupling to
AC
or
DC
.
Adjust signal to desired display height with attenuator switch.
Select time coefficient on the
TIME/DIV.
switch.
Set trigger point with
LEVEL
knob for normal triggering.
Trigger complex or aperiodic signals with longer
HOLD OFF
-time.
Amplitude measurement with Y fine control at right stop (
CAL.
).
Time measurement with time fine control at right stop (
CAL.
).
Horizontal expansion 10 fold with
X-MAG. (x10)
button depressed.
External horizontal deflection (
X-Y mode
) with
XY
button depressed (X input:
CH II
).
Component Tester
Press
COMP. TESTER
button (on). Connect both component terminals to
COMP. TESTER
jacks.
In-circuit test:
Circuit under test must be disconnected from battery or power (pull out power plug),
signals and ground (earth). Remove all signal connections to HM303 (cable, probe), then start testing.
Short Instruction for HM303
