Performance Tests Model
8901B
Audio
Synthesizer
Frequency (HZ)
50
000
100
000
50
20
16.
Set the audio synthesizer
to
10
kHz
at
+5
dBm.
Connect
its
output
to
the audio input of the
AM/FM
test
source. (See Figure 4-2.) Fine adjust the level for
a
Modulation Analyzer display of
100
kHz
times the calibration factor of step 5. (For example,
if
the calibration factor of step
5
is
100.4%, set the level
for
a display
of
100.4
kHz.)
FM
Limits (kHz)
Lower Actual Upper
98.9
-
101.1
94.9
-
105.1
98.9
-
101.1
94.9
-
105.1
NOTE
Flatness
of
the audio synthesizer
is
critical
for
this test.
If
the audio
synthesizer
has
leveling capabilio, switch it
on.
17.
Set the audio synthesizer
to
the frequencies in the following table. For each setting, the Modulation
Analyzer’s display should read between the limits indicated in the table.
I
I
I
I
I
18.
On the Modulation Analyzer, set
HP
FILTER
to
50
Hz
and LP FILTER
to
3
kHz.
19. Set the audio synthesizer frequency
to
1
kHz.
Set the level for
a
Modulation Analyzer display of
20.
On the Modulation Analyzer, press AM. Momentarily disconnect the audio input
to
the AM/FM
50
kHz peak deviation.
test
source and note the residual AM displayed on the Modulation Analyzer.
Residual
AM:
%
21.
Reconnect the audio input of the AM/FM
test
source. Note the AM displayed on the Modulation
Analyzer. The displayed
AM
minus one-half the residual
AM
noted in step
20
should be
0.2%
or less.
FM Rejection
at
1
kHz
Rate;
50
kHz
Peak Deviation:
0.2%
FM
Distortion, Accuracy, and Rejection-455
kHz
IF
22.
Connect the FMt32 output of the AM/FM
test
source
to
the Modulation Analyzer’s INPUT.
23. On the Modulation Analyzer, key in 3.1 SPCL
to
set the
IF
to
455
kHz.
Press FM.
24. Set the audio synthesizer level for
a
Modulation Analyzer display of 5
kHz
peak deviation.
25. On the Modulation Analyzer, press AM. Momentarily disconnect the audio input
to
the AM/FM
(See Figure 4-2.)
test
source and note the residual AM displayed on the Modulation Analyzer.
Residual AM
%
26. Reconnect the audio input of the AM/FM
test
source. Note the
AM
displayed on the Modulation
Analyzer. The displayed AM minus one-half the residual AM noted in step 25 should be 0.2%
or less.
FM Rejection at
1
kHz
Rate; 5
kHz
Peak Deviation:
0.2%
4-12
Performance Test 2
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