Goldstar OS-7020 Service Manual page 32

O. l
5
div
@
Check/adju:st attenuation compensation.
(ATT :
+
10,
+
100 )
a. Set the input coupling switch to DC.
b. Connect lhe square-wave generator to the CH1 ~CH2) input terminal
check for a square wave that is flat (flat top) under the following
sellings.
ATT VOLTS/DIV
Square-wave-generator output
+10
0.1 V 0.5 V
+ 100
1V
5 V
c. Adjust lhe trimmer capacitors (refer to the circuit board illustration
with adjustment location - page
60)
for a square
wave
that is flat
(flat lop) under lhe fo_llowing settings.
ATT VOLTS/DIV
Square-wave generator
Adjust
output
CH1
(CH2)
+10 0.1 V
0.5 V
VC302(VC402)
+ 100
1 V 5 V
VC 304 (VC404).
. @
Check/adjust input capacity (ATT:
+
10,
·+
100).
a. Connect the L-C meter to the input connector.
b. Check the input capacity for appr oximate
Iy 20
pF •
c. Adjust the trimmer capacitors for a 2 pF input capacity under the
following settings.
31