TYPE 321 OSCILLOSCOPE
F A C T O R Y
C A L I B R A T I O N
P R O C E D U R E
Quick check for long ends, unsoldered joints, wire dress, etc. Preset all pots
and trimmers to mid-range. Check front panel controls for position and operation.
1.
CHECK POWER SUPPLY RESISTANCES TO GROUND
Primary of Power Transformer -- Infinite
10 Volts. Regulated to Converter -- Infinite
The following readings taken with Com. Lead of Ohmmeter on ground:
+45
200
Q
+45 Dec.
600
Q
+10
80
Q
+6.3
8
Q
+6.3 Dec.
8
Q
-10
1000
Q
-10 Dec.
1400 Q
-45
4000 Q
-7 2 0
5 Meg Q
*NOTE: These readings will vary depending on range used. Use lowest
possible range.
1A.
CHECK RESISTANCE ACROSS BATTERY TERMINALS
With common lead of ohmmeter on Neg. terminal read 300 Q, reverse leads
and read infinite. Power switch off.
2.
CHECK VOLTAGES AND REGULATION
Adjust 10 Volts regulated , (Check D.C. regulation.) 105-125. Measure
voltages from converter.
TYPICAL MEASUREMENTS
+45
45.5
Ripple
5 mv
+45 Dec.
47
2
mv
+10
9.5
3
mv
+6.3
6.3
150
mv
+6.3 Dec.
6.3
100
mv
-1 0
- 1 0
3
mv
-10 Dec.
-1 1
2
mv
-45
-44
5
mv
-7 2 0
-7 2 0
750 mv
January i
960
321-1
