Fluke 6060B Instruction Manual 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