Wavetek 142 Instruction Manual page 23

concise and
are written for the experienced
electronics
technician or
field
engineer having
a
working knowledge
of
this
type of instrumentation.
WAVETEK
maintains
a
factory repair
department
for
those
customers not possessing the necessary
test
equipment
or
personnel
to
maintain
this
type of instrument.
If
an
instru-
ment
is
returned to
the factory
for calibration or repair, a
detailed
description
of the
specific
problem
should be
attached. This
will
hasten
turnaround
time.
4.2.1
Recommended
Test
Equipment
The
following
test
equipment
(or
equivalent)
is
recom-
mended
for this calibration
procedure.
A
quick checkout
of the instrument can be
made by comparing
the
indicated
parameters with
those given
in
the
specifications portion of
Section
1.
NOTE
The
entire calibration
procedure must be
read
first
to
determine
initial
control settings
and
test
equipment
connections required before
attempting
recaiibration.
The
steps
of
this
pro-
cedure should
be performed
in the
sequence
given,
and
the parts within each
step
should
also
be performed
in
the
sequence
given.
Table
4-1.
TEST EQUIPMENT
Required
Recommended
Name
Characteristics
Manufacturer Model
Oscilloscope
To 250
MHz
Tektronix
454
Oscilloscope
To
30
MHz
Tektronix
544
Plug-In Dual channel Tektronix
1A1
Plug-In
Peak
mV
measuring
capability
Tektronix
1A5
Distortion
Analyzer
To 600 kHz
Hewlett-Packard
334A
Spectrum
Analyzer
Display
To
50
MHz
Hewlett-Packard 141S
IF Section
Hewlett-Packard
8552
\
RF
Section
Hewlett-Packard
8553L
Differential Microvolt dc
Voltmeter measurement
Counter To
10
MHz
0.1% of reading accuracy
4.2.2
Preliminary Procedures
1.
Set the front panel controls
to
the positions
listed
below:
FREQ
Hz
X
100
FREQ
DIAL
10
WAVEFQRM
SELECTQR
Sine
30V
P-P
MAX
3/4ths of
full
CW
DC QFFSET
0
SYMMETRY NQRM
OUTPUT ATTEN
-10
dB
VERNIER
full
CW
MIN/MAX
full
CCW
4.2.3
Power Supply
Regulation
2.
Following the
instructions
in
paragraph
4.1.2, attach
the
Power Supply
Board
to
the
rear plate of
the
instrument.
3.
Connect
ac
power
to
the instrument, and connect the
voltmeter
leads to
TP1 (common) and
TP2
(-M5 V)
on
the
Power Supply
Board. See Figure 4-4.
4.
Adjust
R21
for a
reading of -t15
Vdc ±20
mV
on
the
voltmeter.
5.
Check
the voltage
at
TPS
for
—15
Vdc ±50
mV;
at
TP4
for
±28 Vdc ±400 mV;
and
at
TP5
for
—28 Vdc
±400 mV.
6.
Replace the board
and
the dust
cover,
and
allow the
generator to
warm
up
for at least
Vi
hour before
calibration.
4.2.4
VCG
Amplifier
—
Zero
Offset
Adjustment
7.
Connect
a 5.1 ki2 resistor to each
test
lead of the
differential
voltmeter
for isolation to
prevent
inte-
grated
circuit oscillations.
8.
Set
FREQ HZ
to
X
100,
FREQ
DIAL
to
full
clock-
wise extreme,
FREQ
VERNIER
to
CAL,
and
SYM-
METRY
to
NORM.
9.
Set the voltage between
IC3(2),
and
IC3(3) to
0
Vdc
±100 pV,
using
R107.
See Figure 4-4.
10.
Set the voltage
between
IC4(2),
and
IC4(3) to
0
Vdc
±100
/xV,
using
R1
13.
11.
Set the voltage between
IC5(2),
and
IC5(3) to 0
Vdc
±100 mV,
using
R123.
12. Set the voltage
between
IC6(2),
and
IC6(3) to
0
Vdc
±100
mV, using
R
125.
4-2
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