HP 3465B - Ohms Converter Adjustments (R58 and R69); AC-DC Converter Adjustments

Section V
ADJUSTMENT PROCEDURES
Model 3465B
Table 5-9. Power Supply Jumpers.
READING
POWER SUPPLY JUMPER
LO HI
16 8
4 2
1
NOTE 1 .8961 0
0
0 0 0
.8962
.8984
0 0
0
0
1
.8985
.9008
0 0 0
1 0
.9009
.9032
0 0 0 1
1
.9033
.9057
0 0 1 0 0
.9058
.9082
0
0 1 0 1
.9083
.9108
0 0 1 1 0
.9109
.9134
0
0 1 1
1
.9135
.9161
0
1 0 0 0
.9162
.9189
0 1 0 0
1
.9190
.9217
0 1 0 1
0
.9218
.9245
0
1
0
1
1
.9246
.9274
0 1
1 0
0
.9275
.9304
0
1
1 0
1
.9305
.9335 0 1 1 1 0
.9336
.9366
0
1 1 1 1
.9367
.9397
1
0 0 0
0
.9398
.9430
1
0 0
0
1
.9431
.9463
1 0
0
1
0
.9464
.9497
1
0 0
1 1
.9498
.9532
1
0
1
0
0
.9533
.9568
1
0
1 0
1
.9569
.9604
1
0
1 1 0
.9605
.9641
1
0
1 1
1
.9642
.9680
1
1 0 0 0
.9681
.9719
1
1 0 0
1
.9720
.9759
1 1 0 1 0
.9760
.9800
1
1 0
1 1
.9801
.9843
1
1 1 0 0
.9844
.9886
1
1 1 0 1
.9887
.9930
1 1 1 1
0
.9931
NOTE 2
1 1 1 1 1
"0" = Remove Jumper
"1" = Leave Jumper In Place
NOTE 1. For Readings less than .8922, adjustment can
not be made. Check A1CR17 zener voltage
for 6.95 V ± 0.25 V.
NOTE 2. Adjustment cannot be made for readings
greater than 1.0000. Check A1CR17 zener
voltage for 6.95 V ± 0.25 V.
b. Connect ground to the gate of A1Q16 at the
junction of A1C7.
c. Connect the Digital Voltmeter to DCTP.
d. Adjust R50/R51 for a Digital Voltmeter reading at
DCTP of less than 1 m V.
5-37. Ohms Converter Adjustments (R58 and R69).
5-38. A Digital Voltmeter a 1 kf2 ± 0.01% resistor and a
10 Mf2 ± 0.01% resistor are required for this adjustment.
a. Set Multimeter function to OHMS (f2) and range to
2K.
b. Siort the Multimeter input terminals (Vf2 and COM).
c. Connect Digital Voltmeter to junction of A1R78 and
A1Q25 gate.
d. Adjust A1R69 (10 Mf2 ADJ) for a Digital Voltmeter
reading of < 0.5 mV.
e. Remove the input short and the Digital Voltmeter.
f. Put the 1 kf2 resistor across the input terminals and
adjust A1R58 (1 kfi ADJ) for Multimeter display of
1.0000 ± 2 counts. If R58 does not have enough range to
achieve this display, cut jumper B to introduce A1R57 and
readjust A1R58 for the 1.0000 ± 2 count display.
g. Change Multimeter range to 20 M.
h. Remove the 1 kf2 resistor at the input terminals and
apply a 10 Mfl resistor across the input terminals. Adjust
A1R69 for a display of 10.000 ± 3 counts.
i. Remove the 10 Mf2 resistor at the input and change
range to 2 K.
j. Repeat Steps f, g, h and i (1 kfi ADJ and 10Mf2
ADJ) until both adjustment specifications of Steps f and h
are met.
5-39. AC - DC Converter Adjustments.
5-40. AC Overall Gain Adjustment (R204, J11, J12, R206,
R208). An AC Standard Is required for this adjustment.
Set the AC Standard for an output of 1 V ac at 200 Hz.
Set the Multimeter FUNCTION to ACV (~ V) and RANGE
to 2 V. Connect the AC Standard output to the Multimeter
Vf2 and COM terminals.
5-41. Procedure.
a. Adjust R204 for a Multimeter display of 1.0000 V
b. If R204 has insufficient adjustment range, clip open
JIl.
c. If there is .still insufficient adjustment range, clip
open J12.
d. If there is still insufficient adjustment range, clip out
R206.
e. If there is still insufficient adjustment range, clip out
R208.
5-42. AC Converter High Frequency Adjustment (C45).
An AC Standard is required for this adjustment.
a. Set Multimeter function to ACV (~ V) and range to
2 V.
b. Apply a 0.1 V, 20 kHz signal with the AC Standard
to the input terminals.
c. Adjust A1C45 (CONVERTER HIGH FREQ ADJ) for
a Multimeter display of .1000 ± 1 count.
d. Maintain the AC Standard for the following adjust
ment.
5-10