MAINTENANCE
CALIBRATION ADJUSTMENTS
e. Connect the
UUT
RF
OUTPUT
connector to the Modulation Analyzer
input.
f. Program
the Modulation Analyzer to measure AM + Peak, in a 0.05-kHz to
15-kHz bandwidth,
g.
Alternately measure + PEAK and
-
PEAK and adjust the AM
Depth
Adjustment,
R421, until the readings are symmetrical, about
90%.
h. Replace the AM Depth adjustment access screw.
5. RF Level Adjustment
TEST
EQUIPMENT
Power Meter and
Sensor
REMARKS
The UUt must be operated at room
temperature
for
at least one
hour with the module
plate covers
in
place before continuing
with
this adjustment procedure.
This
adjustment
is
required
if any of
the
following events occur:
The Output Assembly, A2A4, or
the
Attenuator, A2A5 has been replaced.
The AM Depth
adjustment is made.
The LEVEL DAC or any associated components are replaced.
The RF
level adjustment has been inadvertently changed or shifted.
CAUTION
Thia
adjuatment directly affects the output level and should
not be adjusted
Indiscriminately.
PROCEDURE
With
the
UUT
programmed to +9 dBm, adjust the RF Level Adjustment, R31
1,
for
+9-
dBm output
as
measured with the Power Meter.
a.
Program the UUT to [RCL]
[9][8],
then program the UUT to 350 MHz, +9
dBm,
and
turn all modulation OFF.
b. Zero
the
Power Meter.
c. Remove the
RF Level
Adjustment access
screw from the bottom module
plate cover.
d.
Connect the Power Sensor to the UUT RF connector.
e.
Adjust
RF Level Adjustment, R3
U
,
for
a
reading
of
exactly +9 dBm on the
Power
Meter.
4C-9
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