Unleveled Condition - Fluke 6060B Instruction Manual

maintenance
TROUBLESHOOTING
AND REPAIR
Table 4D-15.
Attenuator Level Control
AMPLITUDE RANGE
IN
DBM
ATTENUATOR SECTIONS INSERTED
]
NDICA1
"ED
BY
X
AM Off AM On
A6DBL
A1
2DBL A241L A242L A243L A244L A245L
7.0 19.0
1.0 9.0
1.0
6.9
"5.0
0.9 X
"5.0
0.9
-11.0
"5.1
X
-11.0
-S.1
-17.0 "11.1 X
X
-17.0
"11.1
-23.1 -17.1 X
"23.1 -17.1 -29.1
"23.2
X
X
"29.1 "23.2
-35.1 -29.2
X
X
"35.1
"29.2
-41
.1
-35.2
X X
X
-41
.1
"35.2 "47.1 -41
.2
X X
"47.1 "41
.2
"53.2 "47.2
X
X
X
"55.2 "47.2 "59.2
-53.3
X
X
X
-59.2
"53.3
"65.2 "59.3
X X X X
"65.2
"59.3
"71.2 -65.3
X X
X
"71.2 -65.3 -77.2 -71.3
X X
X X
"77.2 "71.3 "83.3 "77.3
X
X
X X
"83.3 "77.3 -89.3
"83.4
X X X
X X
-89.3 "83.4 -95.3
"89.4
X
X X X
"95.3 "89.4
-1 01 .3
-95.4
X
X
X
X X
"101
.3
"95.4 -107.4 -101
.4
X
X X
X
X
-107.4 "1
01.4
"113.4 "107.5
X X
X X
X X
"113,4 "107.5
"119.4 -113.5
X X
X X
X
"119,4 "113.5
"125.4 -119.5
X
X X
X X
X
-125.4 "119.5 "151.4 -125.5
X X X
X X
X
-147.0 -125.5
-147.0 -131.5
X X
X
X X
.
X X
Table 4D-16. Attenuator Levels
ATTENUATOR
PROG LEVEL
SPECIAL FUNCTION
OBSERVED LEVEL
(NOMINAL)
6dB
+6dBm
+6dBm
12dB
OdBm
—
OdBm
24dB
£1
-1 2dBm
—
-1 2dBm
24d5
£2
-1 2dBm
83
-12dBm
24dB
£3
-1
2dBm
84
-1 2dBm
24dB
£4
-1 2dBm 85
-1
2dBm
24dB £5
-1 2dBm
86
-1 2dBm
4D-44.
Unleveled Condition
If
there are self-test failures
and/or
unleveled
indications, the
problem
is
probably
in,
or
prior
to,
the
ALC
loop.
If
the
problem
is
isolated to a
specific
frequency
band (or
bands)
and
other
bands
work
properly,
check
signal
inputs
and controls to the various
filters
that
precede
the
modulator. See Table
4D-7 Band,
Filter,
and Frequency Data
for
band
definition. If all
frequency
bands
are
affected,
the leveling
ALC
loop
or associated
controls
and
inputs are
probably
at fault.
TP6
(modulator control voltage)
is
a
good place to monitor.
With
the
instrument
programmed
to
+
1
3
dBm,
the voltage
on
TP6 should be between
+2V
and
+SV
dc
(+4V
to
+5V
dc typical).
Another place to
monitor
is
TP7 (ALC
control
voltage).
With
the
instrument
programmed
to
+13 dBm,
and
the level
correction disabled
[SPCL]
[S][l],
the
4D-19