A1
Attenuator
Replacement
Caution
The
tracking
generator
assemblies
are
static
sensitive
.
P
erform
assembly
procedures
at
static-safe
work
stations
.
Refer
to
Figure
7-1
for
an
example
of
a
static-safe
work
station.
Removal
1.
Remove
the
instrument
cover
as
described
on
page
7-7.
2.
Remove
W9
1
and
W10
2
.
See
Figure
7-3.
3.
Use
a
0.05-inch
hex
driver
to
loosen
the
two
set
screws
4
on
the
attenuator
shaft
adapter
6
.
Pull
the
attenuator
knob
3
and
attenuator
shaft
adapter
forward
as
far
as
it
can
go
.
4.
Remove
the
two
screws
5
holding
the
attenuator
to
the
attenuator
bracket.
Replacement
5.
Rotate
the
attenuator
shaft
fully
clockwise
.
6.
Connect
the
replacement
attenuator
to
the
attenuator
bracket
by
replacing
and
start
tightening
the
two
screws
5
.
7.
Replace
the
attenuator
adapter
and
secure
it
with
the
two
allen
screws
4
.
8.
Move
the
attenuator
to
align
the
knob
properly
with
the
front-panel
markings
.
Tighten
the
set
screws
5
to
six
inch-pounds
.
9.
Reconnect
W9
1
and
W10
2
.
Tighten
them
to
eight
inch-pounds
each.
7-8
Service
Information
HP
85640A
RF
T
racking
Generator
Operation
and
Service
Manual
Summary of Contents for 85640A
Page 2: ...HP 85640A RF Tracking Generator Operation and Service Manual ABCDE Printed in USA ...
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