Noise Check; Adjustment And Calibration; Power Supply Adjust (+45 V); Bias Adjust (R15) - HP 465A Operating And Service Manual

Section V
Paragraphs 5-12 to 5-17
Figure 5-3
STD-8-0089
5-12.

NOISE CHECK.

a. An AC Voltmeter (-hp- Model 33lA) and a
1 megohm shielded resistor (refer to Figure
5-3) will be required for this test.
b. Connect ac voltmeter to Model 465A OUT­
PUT; RANGE to .003 V .
c. Set Model 465A GAIN to 40 db.
d. Connect 1 megohm shielded resistor across
Model 465A INPUT.
e . AC voltmeter must read less than 2 . 5
(or 25 microvolts referred to input).

5-13. ADJUSTMENT AND CALIBRATION

PROCEDURE.
5-14. The following is a complete Adjustment and
Calibration Procedure for the -hp- Model 465A
Amplifier. These operations should be conducted
only if it has previously been established by the
Performance Checks, Paragraph 5-5, that the Model
465A is out of adjustment. Indescriminate adjustment
of the internal controls to "refine" readings may
actually cause more difficulty.
outlined below do not rectify any discrepancies
which may exist, and all connections and settings have
been rechecked, refer to Paragraph 5-21, Trouble­
shooting Techniques, for possible cause and recom­
mended corrective action.

5-15. POWER SUPPLY ADJUST (+45 V).

a. A DC Voltmeter (-hp- Model 3440A/3445A)
will be required for this test.
Set voltmeter FUNCTION to DC; RANGE
b.
to 100.
5-4
Figure 5-3. Shielded Load for Residual Noise Check
nw
If the procedures
No. Description
Connector, male
1
2 Connector, male,
Lug, terminal, 90 0
3
n ,
4 Resistor, 1 M
metal film
5 Washer, into lock
6 Spacer, 6-32 threaded
7 Shield
Screw, bind. head, 6-32 x
8
1/4 inches
c. Connect positive lead to + side of C20;
common lead to common.
should read +45 v (±l v).
d . If not, adjust R3 2 for proper reading.
5-16.

BIAS ADJUST (R15).

a. A DC Voltmeter (-hp- Model 3440A/3445A)
will be required for this test.
b. Set dc voltmeter FUNCTION to DC; RANGE
to 100 V.
c. Connect positive lead to + side of C15;
common lead to common.
should read +23 v (± O . 5 v).
d. If not, adjust R15 to obtain proper reading.
5-17.

1 MC ADJUST (C5).

a. A Test Oscillator (-hp- Model 651A) and
an AC Voltmeter (-hp- Model 331A) will be
required for this test.
b. Set Model 465A GAIN to 20 db.
c. Connect oscillator OUTPUT to Model 465A
INPUT. Set oscillator frequency to 1 Mc;
adjust output to 1. 0 v rms (use ac voltmeter to
verify).
Connect ac voltmeter to Model 465A OUT­
d.
PUT.
e. Adjust C5 for ac voltmeter reading of

5-18. SERVICING ETCHED CIRCUIT BOARD.

5-19. The -hp- Model 465A has one etched circuit
board. Use caution when removing it to avoid
damaging mounted components.
Model 465A
-hp- Part No.
1251-0174
W
/insulator 1251-0175
0360-0042
1/2 w, 1% 0757-0059
2190-0007
0380-0058
1251-0173
2470-0001
DC voltmeter
DC voltmeter
The -hp- part
01775-1
B.
5 v.