Fluke 6060B - Page 146

MAINTENANCE
CALIBRATION
ADJUSTMENTS
n. Program
the
LFSSG
to
10
kHz and
0.7071V
rms
as
measured
by
theDVM.
o.
With the
Modulation
Analyzer,
alternately
measure
+peak
and
-peak
FM,
and
adjust R82
so the readings
are
symmetrical,
about
99.9 kHz
plus
the
noise
noted in
step i.
3. L49 20-kHz
and L50
40-kHz
Notch
Filter
Adjustments
TEST
EQUIPMENT
RF
Spectrum
Analyzer
LFSSG
REMARKS
These
adjustments are
normally not
required
unless
L49, L50,
C123,
C99,C124,C126or
Cl
25 are replaced,
or unless
the
Generator
has been
subjected to
severe
usage.
PROCEDURE
The
20~kHz and
40-kHz notch
adjustments,
L49
and L50,
are adjusted
for sideband level
nulls using the
RF Spectrum
Analyzer.
a. Remove the
instrument
and the
module plate
top covers.
b.
Connect
the
LFSSG
to TP56
(high) and
TP36 (low)
using clip leads.
c.
Program
LFSSG
to
20
kHz
and 0.2V
rms, terminated.
d. Connect
the UUT RF
OUTPUT
to the RF
Spectrum
Analyzer
input.
e.
Program
the UUT
to 300 MHz
and -H3 dBm.
f.
Adjust the RF
Spectrum
Analyzer
to
display
the
signal
centered
on the
display.
g.
Set the
span to
10 kHz/division
and
1-kHz bandwidth.
The 20-kHz
sidebands
should
be visible.
h.
Adjust L49
to
minimize the
20-kHz
sidebands.
i. Program
the
LFSSG
to
40
kHz.
j.
Adjust
L50 to minimize
the 40-kHz
sidebands.
4. VCO
Upper
Clamp
Adjustment,
R104
TEST
EQUIPMENT
Frequency
Counter
REMARKS
This adjustment
is
normally
required
when
the VCO
is
replaced or
when
the Generator
has
been
subjected to
severe usage.
4C-14