Fluke 6060B - Modulation Oscillator and Detector Adjustments

MAINTENANCE
CALIBRATION
ADJUSTMENTS
d. Adjust R309 for an indication of +0 mV ± 0.5 mV.
e. Program the UUT
RF
OUTPUT to ON.
f. Replace the access screws.
2. Modulation Oscillator Level Adjustment
This adjustment sets the modulation oscillator level.
TEST
EQUIPMENT
Modulation Analyzer
DVM
Low Frequency Synthesized Signal Generator (LFSSG)
REMARKS
The modulation oscillator adjustment is normally
required only
when components
in
the
modulation
oscillator
or
modulation
switching circuits have been replaced or the
adjustment has been changed or has shifted.
PROCEDURE
The AM depth, with internal modulation, is adjusted via R419 to equal the AM depth
with a 1-volt peak external modulation signal
as measured
with
the
Modulation
Analyzer.
a. Gain access to the access screws for R419 by removing the bottom
instrument cover and the access screws for R419.
b.
Connect the output of the
LFSSG
to
the
UUT MOD IN connector and
the
DVM using a BNC tee.
c. Program the UUT to RCL98, then
program
the UUT to 350
MHz,
7 dBm,
and
EXT AM at
90%
AM
depth.
d. Program
the LFSSG
for 1 kHz and a voltage of0.7071V rms, as measured
by the DVM.
e.
Connect
the
UUT
RF
OUTPUT
connector to the Modulation Analyzer RF
input.
f. Program the Modulation Analyzer to measure + Peak AM in a 0.3-kHz to
15-kHz bandwidth.
g.
Note
the
measured
AM
depth
reading with the Modulation Analyzer.
h. Turn off the UUT EXT AM control and turn on the INT AM control.
i. Program the UUT for 1000-Hz modulation frequency.
j.
Adjust
R419 for
an
AM
depth
equal to that noted in step
g.
k. Turn off the UUT INT AM control.
f
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4C-6
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