To Prepare A Qam Or Dvb Qam Measurement - Agilent Technologies 89410A Operator's Manual

Using Video Demodulation
(Opt. AYH)

To prepare a QAM or DVB QAM measurement

This task shows you one way to set up a QAM or DVB QAM measurement.
The task uses the RF section (0-10 MHz) receiver and a 32 DVB QAM
signal from the signals disk. Several other tasks in this chapter use this
setup to teach you how to use video demodulation.
1.
Initialize the analyzer:
Press [ ], [
Instrument Mode
89410A: [
input section (0-10 MHz)
89441A: [
RF section (0-10 MHz)
Press [ ].
Preset
Press [ ], [
Instrument Mode
Press [ ], [
System Utility
2.
Supply a 32 DVB QAM signal to the channel 1 INPUT or perform the following
steps to load a 32 DVB QAM signal from the Signals Disk into a data register
and play it through the analyzer's aribtrary source:
Insert the Signals Disk into the internal disk drive.
Connect the SOURCE to the channel 1 INPUT.
Press [ ], [
Save/Recall
Press [ ], [
Return catalog on
Rotate the knob to highlight 32DVBQAM.DAT
], [
Press [
recall trace from file into D1
Press [ ], [
Source source on
3.
Select the optimum range:
Press [ ].
Range
Press the down-arrow key until the Channel-1 Over and Half LEDs are on.
Press the up arrow key one press at a time until the Over LED turns off.
For additional details about selecting the optimum range, see online help
for the [ ], [
Range ch1 range
4.
Select a center frequency and span:
Press [ ], [
Frequency center
Pr ess [ ], 2.5, [
span
The center frequency tunes the analyzer to the carrier frequency. To
obtain reliable carrier lock, the center frequency must be close to the
carrier frequency. For details, see ''Carrier Locking'' in the
Video Demodulation Concepts (Opt. AYA) chapter.
Selecting the correct frequency span is also important when using video
demodulation. The span must be wide enough to include all signal
components, and yet not too wide, or the measurement may be affected
by excessive noise and slower speed. For details, see ''Parameter
Interactions'' in the Video Demodulation Concepts (Opt. AYA) chapter.
9 - 8
], then press:
receiver
].
].
].
vector
], [
memory usage configure meas memory)
], [ ].
default disk internal disk
].
], [ ].
enter
], [
], [
source type arbitrary
] softkey.
], 5, [ ]
MHz
].
MHz
], [ ], 4096.
max time pts
].