Section V
Paragraphs 5-16 to S-20
Model 4342A
5-16.
ADJUSTMENT AND CALIBRATION
PROCEDURES.
5-17.
These paragraphs describe complete
adjustment and calibration procedures for the
Model 4342A. The procedures should be per-
formed when any performance test fails or
when it is known that the instrument does not
meet the specifications or may be necessary
after certain repairs.
Table 5-6 is a sum-
mary of the purpose of each adjustment and
its effect on instrument performance.
Adjustment and assembly locations are shown
in Figure 5-4 and 5-5, respectively.
WARNING
ADJUSTMENTS DESCRIBED IN THIS SEC-
TION ARE ALLOWED FOR QUALIFIED
TECHNICAL PERSONNEL ONLY.
e.
Adjust ASR21 (-25V ADJ) for a reading
of -25V _+O.O25V on DC
Voltmeter.
Note
Voltage ripple should be less than
0.35mVrms for both +25V and -25V
power supplies.
5-19.
OSCILLATOR LEVEL ADJUSTMENT.
An AC Voltmeter and a Digital Voltmeter are
required for this adjustment.
a. Connect AC Voltmeter to 4342A LO and
GND terminals as shown in Figure 5-l.
Monitor dc voltage at AC Voltmater dc
output terminals with Digital Volt-
meter.
WARNING
b.
Set 4342A controls as follows:
ADJUSTMENTS DESCRIBED HEREIN ARE
PERFORMED WITH POWER SUPPLIED TO THE
INSTRUMENT AFTER PROTECTIVE COVERS
HAVE BEEN REMOVED. ENERGY EXISTING
AT MANY POINTS MAY, IF CONTACTED,
RESULT IN PERSONAL INLJURY.
Preparatory to beginning adjustments, remove
top cover by removing the four retaining
screws near side frames (both sides).
Remove
bottom cover with similar procedure.
5-18.
POWER SUPPLY ADJUSTMENT.
A DC Voltmeter (or a DMM) is required for
this adjustment.
a. Turn 4342A power off.
Take out A8
Power Supply Assembly. Reinstall it
with an extender board.
b.
Turn instrument on. Connect DC Volt-
meter plus input lead to plus terminal
of capacitor A8C3 and minus input lead
of voltmeter to chassis.
C.
Adjust A8R12 (+25V ADJ) for a reading
of +25 iO.025V on DC Voltmeter.
d. Connect DC Voltmeter minus input lead
C.
Remove instrument bottom cover and
to minus terminal of capacitor
A8C6
oscillator shield cover labeled with
and plus input lead of voltmeter to names of FREQ AD-J potentiometers and
chassis.
trimmer capacitors.
FREQUENCY RANGE
.........
22k - 70k
FREQUENCY dial
................
5.0
Q RANGE ........................ 30
Q LIMIT
........................
cw
L/C dial ...................
25
(PF)
K dial ......................... 0
C.
Set AC Voltmeter range to 30mV and
Digital Voltmeter range to 1V.
d.
Adjust A8R26 (OSC LEVEL adj.) for
949.0mV -t5mV on Digital Voltmeter dis-
play.
5-20. OSCILLATOR FREQUENCY ADJUSTMENT.
A Frequency Counter is required for this
adjustment.
a. Connect a frequency counter to 4342A
rear panel FREQUENCY MONITOR connector.
b.
Set
4342A controls as follows:
FREQIJENCY RANGE ......... 22k - 70k
FREQUENCY dial ................
2.2
Other controls ....... any settings
5-8
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