Fluke 6060B - Page 148

MAINTENANCE
CALIBRATION ADJUSTMENTS
oscillator
is
adjusted for
a stable
display
on the
oscilloscope at
both upper
and lower
limits.
The
external
reference
input level
to the
Generator
is
reduced
to
determine
sensitivity.
PROCEDURE
a.
Remove
the top
Generator cover
and the
lO-MHz
adjustment
access screw
from the
the module
plate. (See
Figure
4C-3 C240
for 10-MHz
adjustment
location.)
b. Connect
the frequency
standard
to
the reference
input of the
LFSSG.
c.
Connect the
LFSSG
output
to the oscilloscope
vertical input
channel 1
using
a
BNC tee,
and then
connect
the
cable
to the UUT
1
0 MHz IN using
a cable less
than three feet
in length,
d.
Connect the
UUT
rear
panel 10
MHz
OUT
to oscilloscope
vertical
input
channel
2.
e.
Program
the
LFSSG to
10
MHz and 0
dBm.
f.
Set the
UUT rear panel
REF INT/EXT
switch to
EXT.
g.
Set the
vertical
controls
of the
oscilloscope to
display both the
LFSSG output
and the
UUT 10-MHz
signal. Set the
triggering
to
channel I,
and
adjust the
timebase
for
0.
1 us/ div.
h.
Edit
the
LFSSG
to 200 Hz
above 10 MHz
(10.0002 MHz).
i. If the
signals are
unlocked,
adjust
C240 for
a locked
condition.
Verify the
UNCAL
indicator
is not
lit.
j.
Adjust
C240 clockwise
until the two
waveforms
are not
synchronized
(break
lock).
Verify the
UNCAL
indicator
is flashing.
Turn C240
counterclockwise
to
the first
stable, locked
point.
k.
Edit
the LFSSG
to
100 Hz
below
10 MHz
(9.9999 MHz),
l.
Verify
Locked
Condition:
Two wave
forms
synchronized
and
UNCAL
indicator
is not lit.
m. Program
the
LFSSG
to 10 MHz.
n. Reduce
the level of
LFSSG
until
the
signals
displayed
on the
oscilloscope
indicate an
unlock
condition.
0. Increase
the LFSSG
level
until the
oscilloscope
display first
indicates the
locked-point.
Verify
that
this
level is
less
than 300
mV
peak-to-peak
as
measured
with the
oscilloscope.
p.
Perform
Reference
Frequency
Adjustment
procedure
on page
4C’-11 of this
manual.
4C-16