Wavetek 182A Instruction Manual page 22

Table
6-4.
Sine Conversion
Indication: Sine
waveform
problem.
Check
If
Faulty,
Check
1.
Set controls
to
initial
positions
(refer to
paragraph
6.4).
Check
for
normal
operation.
2.
Check
emitter Q1
for
a 4
kHz,
±
1
.25V
triangle.
Go
to table 6-2.
3.
Verify that the
±
1
.25V
triangle
peaks
at
the emitter
of
Q1 agree
within
3%
a.
R62, R63, R64, R65,
R67, R68,
R69 R70
b.
CR7, CR8,
U7.
c.
+15V
supplies.
4.
Select triangle function; check
for
±
1.25V
triangle
at
U13
pin 10.
Go
to table 6-3, step
3.
5.
Select sine
function;
check
for
±
1.25V sine
at
U13
pin 10.
a.
U12
circuitry.
b.
SW12.
6.
Check
sine distortion 50P.
OUT
(HI)
per calibration procedure
(refer to
table
5.1).
a.
R97,
R114
adjustments.
b.
Waveform
symmetry, R45
adjustment
and
table 6-8.
c.
U12
circuitry.
7.
Check
sine amplitude vs frequency per
specifications
(refer to section
1).
C47, C55, C56, C57
Table
6-5.
Square
Function
Indication: Square waveform
problem.
Check
If
Faulty,
Check
1.
Set controls
to
initial
positions
(refer to
paragraph
6.4).
Check
for
normal
operation.
2.
Check CR10
cathode
for
a 4 kHz, approximately
±2V
square wave.
Go
to table 6-2.
3.
Select a
triangle function;
check U13
pin
10
for
a
±
1.25V
triangle.
Go
to table
6-3.
4.
Select
square
function;
check U1
3 pin
1
for a
±1
,25V square.
a.
Q12,
Q13
circuitry.
b.
SW14.
5.
Check square wave
at
50Q
OUT
(HI) for
the
same
20V
p-p
(open
circuit)
amplitude as
the triangle
and
sine.
R106, R110, R111.
6.
Check
rise/fall
times
of 4
MHz
square (508 terminated)
for
<50
ns.
C51
,
C55, C56, C57.
Table
6-6.
TTL Sync
Output
Indication:
TTL sync output problem.
Check
If
Faulty,
Check
1.
Set
controls to
initial
positions (refer to
paragraph
6.4).
Check
for
normal
operation.
2.
Check U8
pin
1
for
a
TTL
level,
4 kHz square.
Go
to
table 6-2.
3.
Check U8
pin
8
for
a
TTL
level,
4
kHz
square.
a.
U8.
b.
CR11, CR12.
4.
Check
SYNC OUT
TTL.
E27, E28, E1 9
wiring.
5.
Check
SYNC OUT
waveform
at
4
MHz,
using a
TTL
load termination
or a
a.
U8.
>600Q
resistive
termination
and
<3
foot
RG58U
coax.
b.
E19 ground
connection.
6-4