Fluke 6060B - Unleveled and AM Troubleshooting

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