Fluke 6060B - Level Troubleshooting

MAINTENANCE
TROUBLESHOOTING
AND REPAIR
Tabl«
4D-12. FM
Ranges
FM
DEVIATION
FM DEVIATION
WITH
FMRN
CHz>
LOW-RATE
FM
OPTION
(Hz)
0
-
999
0
-
99.9
1
1000
-
9990
100
-
999
2
1G00O
-
99900
1000
-
9,990
4
Table
40-13. FM DAC Control
FM
DEVIATION
(Hz)
FM
deviation
WITH
LOW
RATE FM
OPTION
(Hz)
FM 0
-
9
(Bits)
0
-
999
1000
-
9990
10000
"
99900
0
-
99.9
100
-
999
1000
-
9,990
FM
Deviation
/.I
FM
Deviation
FM
Deviation
/10
FM
Deviation
/TOO
I
4D-40.
LEVEL
TROUBLESHOOTING
If
the
Generator level is
inaccurate
or an
unleveled
condition
exists,
the
A2A5
Output
assembly
or the
A2A6
Attenuator
assembly
is
probably
at
fault. If an
unleveled
condition
exists,
the problem
is in
the
circuitry
ahead of
the
detector.
Go to
the
paragraph
in this
section
entitled
Unleveled
Condition,
If there is
no
unleveled
condition,
the problem
is likely in
the circuitry
following
the ALC
Loop,
which
includes the
Attenuator/
RPP, the
heterodyne
circuit, and
the
output
amplifier,
Q215.
If the
level
problem
only exists
below
245
MHz,
then
troubleshoot
the
heterodyne
circuitry.
If the
problem is
not
frequency
dependent
and if
the level
is
accurate
above
+7
dBm
but
inaccurate
below
+7
dBm,
then
the A2A5
Attenuator/
RPP is
at
fault.
4D-41-
Output
Assembly
Teat Point
Signal
Information
Table 4D-14
presents
the
nominal
characteristics
of the
signals at
the various
test
points
on
the
Output PCA.
Not only
the range of
the
signal, but
also
the
expected
value
for the
Instrument
Preset
State
[RCL]
[9][8],
are given.
4D-42.
ATTENUATOR
LEVEL
CONTROL
Table 4D-14
lists the
Attenuator
assembly (A2A5)
sections
that are
inserted m
the RF
output
path for the
various level
ranges of
the
generator.
This
information is
useful in
isolating a
faulty
section.
The sections
are labeled by
the
control
line
mnemonics at
latch
U27 on
the
Controller
PCB.
Note
that the
section is
inserted
in the
RF
output
path when
there is no
power applied
to the relay.
If
the Level
problem
exists
above
+7 dBm, the
through path
(0
dB
attenuation)
of
the
Attenuator
may
be faulty.
4D-43.
Attenuator
Check
Attenuator
problems
are most
likely
to be relay
contact
problems.
To
isolate
the faulty
attenuator
section, connect a
power
meter
to the
RF
OUTPUT
connector,
and
check
the
nominal levels per
Table
4D-16 at
both
0.2-MHz and
1050“
MHz
frequency.
4D-17