Wavetek 132 - Troubleshooting - Procedures; Panel and Cover Removal; Component Replacement Procedures

pected,
the
following
procedure
may
be
used to
isolate
the
bad
1C.
1.
Set clock
frequency
to 1 .0
MHz.
2.
Verify that a
clock
pulse
appears at
pins 9
and
12
of
IC2
through IC13.
3.
Short
circuit test
point
RT to DG.
(This
opens
the
digital
feedback loop.)
4.
Check
for logic
"zero"
at
pins
3
and 5
of
IC2
through I
C
1
3.
5.
Check
for logic
"one"
at
pins 2
and
6
of
IC2
through IC13.
6.
Check
logic
states
of all
gates
using
the
known
states
of the
register.
REMOVAL
OF
DUST
COVERS
AND
PANELS
1.
To
gain
access
for
calibration
or
maintenance,
proceed as
follows:
a.
Remove
power cord.
b.
Loosen the
two
knurled
captive
screws
on
the rear
panel.
c.
Pull off the
rear
panel.
d.
Remove the
cover.
2.
To
gain
access
to the
digital board,
proceed
as
follows:
a.
Remove the
four screws
holding
the
digital
board.
b.
Rotate the
board
upward
using
the rear
of
the
instrument as a
pivot point.
3.
To
gain
access
to
the
analog
board
and/or the
main
board, proceed
as
follows:
a.
Remove
digital board.
b.
Remove
one screw
and
shoulder
washer hold-
ing 5
V
regulator to
side
plate,
c.
Remove
all knobs
below the
push button
switches.
d.
Remove two nuts,
washers,
and
insulators
holding the
switch assembly
to
the front
panel.
e.
Remove two
screws
holding
rear
bracket to
chassis.
f.
Disconnect
all AMP
pin
connections
between
main board
and
analog board.
g.
Unsolder two
wires
from 50£2
OUT con-
nector.
h.
Unsolder
coaxial
cable
from
main
board to
50f2
attenuator.
i.
Remove
four screws
holding
analog board
to
side plates.
j.
Carefully
lift rear
of analog
board
to
clear
the sine
converter and
slide
analog board.
rear
bracket and
digital board away
from
the
front
panel.
4. To
gain
access to any
part mounted
on
upper
rear
bracket,
proceed as
follows:
a.
Remove
digital board.
b.
Remove
two screws
holding lower
and
upper
rear
brackets to chassis.
c.
Remove one
heat
sink
mounting
screw.
d.
Remove
bottom
transformer
mounting
block
screw.
e.
Remove
the two
screws, iock
washers
and
hex nuts
holding
two
wafers
of
FREQ
HZ
switch
to
bracket assembly.
f.
Remove two
screws
holding
bracket
assembly
to main
board.
g.
Carefully
pull
bracket
assembly to
rear to
obtain
working
room. Enough
slack
is avail-
able in
the wiring
for all
normal
operations.
5. To
remove
front
panel,
proceed as
follows:
a.
Remove
rear panel and
dust cover
as
pre-
viously
described.
b.
Remove all
knobs,
except
frequency
dial.
c.
Unsolder BNC
connections.
d.
Tag
and
unsolder
frequency-dial
potentio-
meter
leads.
e.
Pull light
bulb
from
indicator lens.
f.
Remove
four
front
panel
retaining screws.
g.
Remove
two
hex
nuts,
lock
washers, and
shoulder
washers
holding switch
bracket
as-
sembly
to front
panel.
h.
Carefully
pull off front
panel
with
frequency
dial/potentiometer
still attached.
REPLACEMENT
OF
SWITCH
WAFERS
AND
PO-
TENTIOMETERS
1.
To
replace
FREQ
HZ
switch wafer
C
or D
or the
FREQ
VERNIER
potentiometer,
proceed
as
follows:
a.
Remove
rear panel
and dust
cover as
pre-
viously
described.
b.
Separate
bracket
assembly
from chassis
as
previously
described.
c.
Tag and
unsolder
leads
to part
being re-
placed.
d.
Pull defective
part
off shaft and
repair
or
replace with
recommended
replacement part.
2.
To
replace FREQ
HZ
switch
wafer
A
or
B,
proceed
as
follows:
a.
Remove
rear
panel and
dust cover as
pre-
viously
described.
b.
Remove
front
panel as
previously described.
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