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NOTE
Due to
the
interaction between the
two adjustments the
procedure
must be
repeated
a
number
of
times.
9.
Repeat steps 5-8
until no
adjustment of R34 and
R38 is
required
to obtain the
10.0
dBm and 1.0
dBm
readings
on
the
CRT
RF
level
display.
3.3.8
WATTMETER
1.
Remove System Analyzer
bottom
cover
and
watt-
meter
(A17A1)
cover.
2.
Select monitor function and Gen/Mon
Mtr
dis-
play.
3.
Set the step attenuator on the
front
panel to the
10 dB position
and select the
RF IN/OUT
port.
4. Set the
Offset
(R20) and Gain (R7)
pots
in the
halfway
position.
5. Connect a calibrated 1 watt 500
MHz
generator,
using
a 600
MHz
low-pass
filter to filter out sec-
ond
harmonic,
to the RF
IN/OUT
port.
6. Adjust the
OFFSET (R20) pot
on the wattmeter
board
(see
Figure
3-12)
for an input
level reading
of 1 watt on the CRT
display.
7. Connect a
calibrated
50 watt 500
MHz
(again
use
a 600 MHz
L-PF
to the RF
IN/OUT
port).
8.
Adjust the
gain
(R7)
pot
for an
input
level
ready
of 50 watts on the CRT
display
of 50
watts.
NOTE
Due to
the
interaction between
the
two
adjustments
the
procedure
must
be
repeated a
number of
times.
9.
Repeat
steps
5 through
9
until no
adjustment of
R20
and
R7
is
required
to obtain the
1
watt
and
50
watt
readings on the CRT wattmeter
display.
3.3.9 SCOPE COMPENSATION
1.
Remove Front Panel Interface
Board
(A15) and
place
it on the appropriate extender
card.
2.
Turn System Analyzer
ON
and select
DC
scope
display.
3.
Apply
a 1
Vp-p square wave to the vertical scope
input.
4. Adiust Cll on the Front Panel
Interface
board
(see
Figure
3-3) so that
the waveform on the scope
dis-
play
has
not
overshoot or
undershoot
(see
Figure
3-13).
3-19
'
~
l'lt
'
1-
' I -
OVERSHOOT
~
"""
~
"""
,.
"""
,.
..
.Ill""
~
-
....
~
-
~
-
~
-r-
CORRECT
-
~
-
1-
-
~
-
~
-
~
,
~
,.
~
,
~
...
~
1-
UNDERSHOOT
...
' " "
...
~
...
~
....
"' "
....
1-
Figure
3-13.
Scope Compensation
3.3 .10 CATHODE
VOLTAGE
CAUTION
Unless the factory
alignment
has
been disturbed
through
repair or
if
the
CRT
adjustments
CRT
intensity
bias,
CRT
horizonta
l
gain, CRT vertical
gain,
and
character
generator,
will
not
align, do not make
the adjust-
ment.
Because of
the
presence of
high
voltages,
+4
KV
and
-
2
KV,
on the
module
requiring
adjustment.
This
adjustment will
requi
re
a high
voltage
probe
capable of measuring
2KV.
Han-
dle
this
monitor
with
extreme
care when
making
this adjust-
ment to
avoid electrical
shock.
1.
Disconnect the System
Analyzer
from power
source. Remove
the
High
Voltage Power Supply
module
and place
it
on the appropriate extender
card.
2. Connect
power to the
System
Analyzer and
turn
the
unit
ON.
3.
While
monitoring
the cathode voltage wire P2-2
(point
2
on
High
Voltage Power Supply
printed
wiring board)
.
Adjust R37
(see
Figure 3-14) for
a
cathode
voltage
of
-
2000 Vdc
±
10 Vdc.
4. When adjustment is completed disconnect power
from System
Analyzer and
reinstall
High
Voltage
Power
Supply.
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