64
Chapter 2
Making Measurements
Example 3: Modulation
4. Knowing that the desired deviation is 25 kHz, and choosing the
modulation index of the first carrier null, calculate the modulating
frequency as follows:
5. Set the modulation rate on the signal generator to 10.412 kHz. If the
signal source doesn't have an accurate internal modulation source,
use an external source. You can use the delta count mode of the
analyzer to accurately set the audio source frequency as follows:
Figure 2-11
Markers Show Modulating Frequency
Modulating Frequency
25kHz
2.401
----------------
=
Modulating Frequency
10.412kHz
=
Table 2-3
a.
Press
FREQ COUNT
to activate the counter function, then press
COUNTER RES
and set the counter resolution.
b.
Press
COUNTER ON OFF
so that ON is underlined, and use the delta
count mode to read the difference between two sideband peaks (see
Figure 2-11).
c.
Now adjust the frequency deviation for a maximum null of the carrier.
d.
Calculate the FM deviation by multiplying the modulation index
(from Table 2-10) by the modulation rate:
e.
FM Deviation = 10.39 kHz
×
2.401
f.
FM Deviation = 24.95 kHz
Summary of Contents for 8560E
Page 21: ...21 1 Quick Start Guide ...
Page 48: ...48 Chapter1 Quick Start Guide Manuals Available Separately ...
Page 49: ...49 2 Making Measurements ...
Page 164: ...164 Chapter2 Making Measurements Example 13 Making Pulsed RF Measurements ...
Page 165: ...165 3 Softkey Menus ...
Page 182: ...182 Chapter3 Softkey Menus Menu Trees ...
Page 183: ...183 4 Key Function Descriptions ...
Page 228: ...228 Chapter4 Key Function Descriptions Key Descriptions Figure 4 3 CRT Alignment Pattern ...
Page 289: ...289 5 Programming ...
Page 323: ...Chapter 5 323 Programming Math Functions Figure 5 10 Display Units ...
Page 339: ...339 6 Programming Command Cross Reference ...
Page 369: ...369 7 Language Reference ...
Page 654: ...654 Chapter7 Language Reference VTL Video Trigger Level ...
Page 655: ...655 8 Options and Accessories ...
Page 665: ...665 9 If You Have a Problem ...
Page 674: ...674 Chapter9 If You Have a Problem Power Requirements Figure 9 2 AC Power Cables Available ...