Goldstar OS-7020 Service Manual page 31

1\
I '
l
I•
I ',
,
,
,
,,
,
5
div
g, Adjust the x
1
AC GAIN
VR302
(CH1),
VR402
(CH2) adjustment for a
flat level.
®·
Check/ adjust vertical_ gain.
a. Set the VOLTS/DIV switch to the 10 m V position and the input coupling
switch to DC.
b. Connect the standard amplitude calibrator to the inpul connector.
c. Set the standard amplitude calibrator for a 50 mVp-p (5 divisions for
display) signal.
d. Check for a display of five divisions,
e. Adjust the GAIN adjustment
VR303
(CH1),
VR403
(CH2) for a display of
5 divisions within 3
%.
C.
Check all the VOLTS/DIV switch settings.
®
Check/ adjust input capae
ity
(ATT:
+
1).
a, Set the VOLTS/DIV switch to the 10 mV position.
b. Set the input coupling switches to DC.
c. Connect the L-C me
re
r to the input terminals.
d. Check the input capacity for approx. 23 pF.
:~ Check/adjust vertic. a l step response.
a~ Set the VOLTS/DIV, switch to the 5 mV position.
b. Set the TIME/DIV switch to the 0. 5 µs position.
c. Connect the Cast-rise, positive output (50 mV, 1 MHz) of the square-
wave
generator to the input. Use a 50
Q
termination and cable.
d. Adjust the square-wave generator output for a 5-divisions display.
e. CH1 - Adjust VC501
so that a square wave is flat.
CH2 Then, adjust VC502 for overshoot of +10 .1 div.
30