HP 8901B Operation And Calibration Manual page 290

Model
8901B
Operation
LOCAL
(keystrokes)
(program codes)
2. Disable auto-ranging by pressing the RANGE
HOLD
key:
RANGE HOLD
E l
4
Range
Hold
LOCAL
(keystrokes)
a
(program codes)
3. On the RF signal source, swith the AM o f f . Measure the residual AM,
Npk,
on the CW signal.
For the purposes of subsequent calculations, assume 0.07% is read on the Modulation Analyzer's
display.
4.
Measure the average residual modulation:
DETECTOR
r - R m s C A L
1
e
7
Detector
For the purposes of subsequent calculations, assume the displayed average residual AM is 0.02%.
5.
Compute:
6.
Compute:
(s
-k
N ) p k
-
30.80%
NPk
0.07%
-
440
7. Use the nomograph to
find N%.
(For the purposes of these calculations, assume N% is
26%)
Compute:
S p k
= (S
+
N ) p k
-
(Npk)(N%) =
30.80%
-
(0.07%)(0.26) = 30.78%.
NOTE
This correction factor
of
<0.1%
of
the peak reading i s typical
of
a
modulation measurement of a quality modulation source measured with the
15 kHz low-pass filter.
Residual Noise Effects 3-193