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Table
6-10.
Trigger
Logic
Indication:
Generator
trigger
and
gate
mode
problems.
Check
if
Faulty,
Check
1.
Set
controls
to
initial
positions
(refer to
paragraph
6.4).
Check
for
normal continuous
operation.
2.
If
generator operates normally
in
continuous
mode, go
to
step
7.
3.
Check
for
0V
at
U9
pins 2
and
5.
SW9.
4.
Check
for
a
TTL
low
at
U10
pin
10.
U9,
+
5V
supply.
5.
Check
for
+5V
at
U10
pin
9.
a.
U10.
b.
CR6, CR15, Q8.
c.
U6.
6.
Check
for
approximately
+
3.5V
at
anode CR6. Check
for
normal
contin-
uous
mode
operation.
a.
CR6,
U6, Q8.
b.
Go
to
table
6-2.
7.
Check
that
U6
pin
4
and
U6
pin
15 vary from approximately
-10V
to
-
15V
as
dial
is
rotated
from
4.0
to .004.
a.
U6, R52, R53.
b.
Go
to
table
6-7.
8.
Go
to
gated
mode (CONT
depressed,
TRIG/GATE
released).
Check U9
pin
2
for
a
TTL
high.
a.
U10.
b.
SW9, SW11,
+
5V
supply.
9.
Check
U9
pin
1
for
a
TTL
high.
a.
U9.
b.
R73,
-
5V
supply.
10.
Check U10
pin
10
for
a
TTL
high.
a.
U9.
b.
U10.
11.
Check U10
pin
9
for
TTL
low.
a.
U10.
b.
Q8.
12.
Check anode
CR6
for
approximately
-
1
,5V.
a.
CR15,
Q8, R78.
b.
CR6.
13.
Check
cathode
CR6
for
approximately
-
0.7V.
a.
U5.
b.
U6.
14.
Check
emitter
Q1
1
for
0
Vdc
±100
mV.
a.
R81
adjustment.
b.
Q9
-
Q11
circuitry.
15.
Connect an
external
TTL
signal to
TRIG
1
N
connector;
check
for
the inverse
of that signal at
U10
pin 10.
a.
E25, E26.
b.
CR13,
CRH.
c.
U9,
SW10.
16.
Press
TRIG/GATE
switch
and check
for
an approximate 20
ns negative
pulse
at
U10
pin
10
following the low-to-high
transition of
the external
signal (increasing
the
frequency
of
the external generator
makes
this
pulse
more
visible).
a.
U9,
SW10.
b.
C29.
17.
Remove
the external
signal
and
verify that
U10
pin
5
goes
from
high
to
low
yyh@n
tfig
MAN
TRIG
switch
is
held depressed.
a.
SW11.
b.
U1Q.
18.
Release
the
TRIG/GATE
switch
(gated)
and check
that
U10
pin
10 goes
from
high
to
low
when
the
MAN
TRIG
switch
is
pressed.
SW9.
19.
Monitor
50Q OUT,
triangle function,
for
0
Vdc
baseline.
R81,
R112
adjustments.
20.
Press
MAN
TRIG
switch
and check 50Q
OUT
for
a continuous
triangle
while the switch
is
held.
Depress
TRIG/GATE
switch
(triggered)
and
verify
a.
U10
or
clock
signal to
U10
from
U7
b.
C29
(pulse
too narrow)
6-7
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