Wavetek 188, Instruction Manual

Page: 36 / 50

Table 8-9. CapJIcltancl
Multiplier (Contlnu.d)
Indication: Problem
on
bottom frequency ranges on l y .
Check
9. Check 400 Hz
frequency (2 . 0
x
1 00).
1 0. Check 40 Hz
frequency (2.0
x
1 0).
1 1 . Check
4 Hz
frequency (4 . 0 X ' )
.
, 2. Check symmetry at 0.2
x
1 00; ensure
triangle is linear.
Table
8-10. Trigger Logic
Indication: Generator trigger and gate mode problems.
Check
1 .
Set
con t r o l s to
initial positions (refer
to
paragraph 6 . 4 ) .
2.
If
generator operates
normally
in continuous mode. go to step 7.
3. Check for OV at U9 pins 2 and 5.
4. Check for
a
TTL low at U 1 0 pin 1 0 .
5 .
Check for
+
SV
at
Ul0
pin 9 .
6. Check for approximately
+
3.5V at anode CR6 . Check for normal contin­
uous mode operation.
7. Check that U6
pin
4
and U6 . pin 1 5 vary from approximately
-
1 0V to
-
1 SV
as dial is rotated from 4 . 0 to .004.
a . Go to gated mode (CONT depressed. TRIG/GATE
released).
Check U9 pin
2
for
a
TTL high.
6-8
Scans by ArtekMedia
=>
2011
Corrective
Procedure
a.
Ra6
adjustment.
b. Ra9. R95. C45.
R93. SW3.
R94.
a. R90
adjustment.
b . U1 t .
c.
Leaky C30, C36 , C45.
C46,
CR6, US, 09.
It Faulty. Check
Check
for normal continuous
ope r a ti o n .
SW9.
U9,
+
5V supply.
a.
U 1 0 .
b .
CRS . CR1 S , 08 .
c. US.
a.
C R S , US. oa.
b. Go
to
table 6 -2 .
a. U6. RS2. R53.
b. Go
to
tab
l
e
6 -7 .
a . U 1 0.
b.
SW9, SW1 1 .
+
5V supply.