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WARNING:
STATIC-SENSITIVE
PARTS-
HANDLE
APPROPRIATELY.
Table 4-2. System Checkout and
Troubleshooting
Procedures
(Cont)
Checkout Procedure
Fault
Troubleshooting
Procedure
MODULATION
CAPABILITY
(Cont)
1
he
presence of
a
DPL
waveform whose
ampl 1tude
i>
variable
wi
t
h
the
Code
3.
Check for t he DPL
signal
at TP6
of the Audio
Synthesizer level
control.
Synthesizer
board.
I
f it is
nut
present,
replace the
Audio
Synthesizer buard.
:l.
Mow the
MODULAT
ION
switch from
CONT
t
o
O FF
and
verify
that
a s
hort
4.
Check
fur
the
DPL sil(nal at TPl of the
Scope
hur~t
of
I
:n
Hz is
present
before the
Amplifier
board
IA2).
If it
is
nut present,
replace
ou
tput
... top:...
the
Scope/
DVM Control
board
(A7).
:t
Mm·e t
he
MODULATION
switch to
5.
If
signal
s witching is okay to
the Scope Amplifier
HUHST.
Ver
ify
that
a t:I:I- Hz tone is
board,
proceed
to
the
SCOP
E
Troubleshooting
o
U
ifHJ\
as
lo>n)!
as t
he
switch
is
held
at
Procedure.
HL;HST.
~
-
Select eontinuous (Cun\) Tone
A
No
exter
nal modulation
I.
Check for
the
mod
ulation signal
at
TP7
of
t
he
mode. Verily
a
Tone A
output
on
the
on
the
CRT
.
Audio
Synthesizer hoard.
If
it
is
not
present,
"""fl~
and
;l\
the
~peaker.
replace
t he
Audio
Synthes
izer
board.
:).
Sele<"l
Tone Hemote mode.
Verify
t
hat
2.
Check for
the
mod
ulation signal
on
pin 66 of the
nwvinl! the MODULATION
switch
Audio
Synthes
izer
board. If
it
is
not
present,
I
rum
OFF to HURST
generates a
replac~
t he
IEEE Interface board (AI 3). or check
>i nl{le
Tone-Hemote-Access Seq
uence.
for the presence
of the
AI
3
jumper
card.
1
;.
Connect
a
microphone to
the
Mic
port.
:!. Continue
tn1ubleshooting at step
:l
of
"No DPL
Turn
up
the
external level
control (Ext
sil(nal
on the
CRT.
··
Level
J
and ,·erify that
speaking
inw
1
he
mike
produces a mod
ulation
s
ignal
on
the :<cope
display.
FREQUENCY
COUNTER
I.
Set the LJLJT
to Generate CW function
Frequency
Counter
does
I.
Check for a 1-kHz signal
at
TP9
of
the
Audio
with
an
output
frequency
of
30
MHz
at
not
work.
Synthesizer
board
(AIO).
If it
is
not
present, check
0 dHm.
as
d
i,;played
on
the Ge
n/Mon
for the
10-M
H
z
signal from
t
he
Frequency-
Mtr
di>pla~·.
Connect the
Antenna port
Standard
Interface
board
(AI6) to
the RF
to
\ he
Frequency
Counter Input port
Synthesizer
module
(A9). If
it
is present,
replace
<Counter In)
of
the
UUT, a
nd
pull
the
the RF Synthesizer
module.
If
it is
not
present,
HF l'nr\
Select
knob
to
the Antenna
replace
the
Frequency-Standard Interface
board.
po~it
ion. Select
F
req Counte
r
display
and
verify a
fr
equency
readinl( of
:lO
2.
If
t he 1-kHz s i::nal is
present,
check for
the signal
MH
z.
to
he
counted
a\ pi
ns
61 and 6:! of
the Processor
Interface
hoard (A
II).
If
it
is
not
present,
replace
2.
Set
1
he U
UT
to
Generate
FM fun ction
t
he Front
-Panel Interface hoa
rd
(A!.~).
and
select
c:en/
Mon
Mtr
d
isplay.
Turn
the
(
'ode
Synthesizer and
external
:I.
If the
si)!nal
is
okay up to
the P rocessor
Inte rface
modulat
ion
sou1
·ces
OFF.
Select
hoard.
replace the
P roces-.>r
Inte rface hoa
rd
.
Narrowband mode on the
bandwidth
~wi
t
ch
!BW
),
and
adjust
the
I KHz
Level
control
lor
an
FM -deviation
4-6
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Table of Contents
Troubleshooting
