Wavetek 171 - Page 18

SECTION U
CALIBRATION
5.1 FACTORY
REPAIR
Wavetek
maintains
a factory
repair
department
for
those
customers
not
possessing
the
necessary
personnel or
test
equipment
to maintain
the
instrument
If
an instrument
is
returned
to the factory
for calibration
or
repair,
a detailed
description
of
the specific
problem should
be
attached
to
minimize
turnaround
time.
5.2
REQUIRED
TEST
EQUIPMENT
DVM
(3%
digit)
Distortion
Analyzer
{1%
F.S.)
HP334A
Oscilloscope
(> 40 MHz
bandwidth,
X 10 horizontal
magni-
fication,
de
triggering
to 1 Hz)
BNC
Termination
(50S2
<
1%,
>
1W)
Frequency
Counter
(6
digits, time
base
accuracy
>
50
ppm)
Low
Frequency
Spectrum
Analyzer
HP3580A
5.3
REMOVING
GENERATOR
COVER
For
main
board access,
remove
the four
screws
in the
lower
ewer, place
the
instrument
on
its
feet and
lift off
the
top
cover.
For later
access
to the
synthesizer
board,
remove
the
four screws
from
the
inside
corners
of the
lower
board
that
attach it
via standoffs
to the lower
cover.
Do
not remove
the
lower
cover unless
necessary,
because
it
supports
front
and
rear
panels.
5.4
CALIBRATION
After
referring
to
the
following preliminary
data, perform
calibration,
as necessary,
per
table
5-1.
If
performing
partial
calibration,
check
previous
settings and
adjustments
for
applicability.
1
.
Unless
otherwise
noted, all
measurements made
at the
500
OUT
connector
should
be
terminated into
a
50S2
{«
1%,
1W)
load.
2.
Before
connecting the
unit
to an
ac source, check
the
ac line
circuit
to
make
sure the
115/230 volt
switch is
set at the
correct
position
(see paragraph
2.2).
3.
Start
the calibration
by setting
the
front
panel switches
as follows:
Dial
2.0
FREQ
MULT
X IK
Mode (toggle
switch)
Toward Dial
Digital
Switch
0.1000
DC
OFFSET
OFF
Function
DC
AMPLITUDE
ccw
ATTENUATION
0
4.
Allow
the unit
to warm
up at least
30 minutes
for
final
calibration.
Start
the
calibration
on
main
board.
All
test points are
located on
the
main
board.
Table 5-1.
Calibration
Chart
Step
Check
Tester
Cal
Points
Control
Settings
Adjust
Desired
Results
Remarks
1 Power
supply
regulation
DVM
TP2
(TP1
ground)
;
R20
+15 +0.01
V
Main
board
2
TP3(—
15V)
-15
+0.05
V
3
Output
dc
Scope or
DVM
50£2
OUT
R116
0±0.01 Vdc
4 balance
AMPLITUDE:
cw
R141