Ceyear 4992A, Руководство пользователя

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Chapter VII Performance feature test
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2) Reset E4438C signal source and set it as follows.
Frequency: 500MHz;
Power: -10 dBm
AM modulation: ON
Modulation rate: 1kHz
Modulation depth: 30%
3) Open the demodulation meter of the tested device by pressing the [Transmitter] hard key or
pressing the [Measurement] hard key and setting the instrument menu. Set the receiver as follows.
Demodulation type: AM
Port: ANT
Frequency: 500MHz;
Reference level: 0dBm
IF bandwidth: 5kHz
Audio filter: 3kLP
Record the test result of the amplitude modulation depth in Table A.16.
4) Change the modulation depth of the signal source according to Table A.16, and record the
reading of the amplitude modulation degree of the tested device in Table A.16.
16. Accuracy of frequency modulation/demodulation measurement
a) Test items
The output signal of E4438 frequency modulation is used as the benchmark to test the accuracy of
frequency modulation deviation measurement of the tested device. The accuracy of frequency
modulation deviation measurement of this instrument is

5%.
b) Test block diagram and meters
The test block diagram and meters are the same as those in RF frequency error measurement.
c) Test steps
1) Connect the device as shown in the figure, start it, and warm it up for 30min.
2) Reset E4438C signal source and set it as follows.
Frequency: 500MHz;
Power: -10 dBm
FM modulation: ON
Modulation rate: 150Hz
Frequency modulation deviation: 0.5kHz
3) Open the demodulation meter of the tested device by pressing the [Transmitter] hard key or
pressing the [Measurement] hard key and setting the instrument menu. Set the receiver as follows.
Demodulation type: FM
Port: ANT
Frequency: 500MHz;
Reference level: 0dBm
IF bandwidth: 5kHz
Audio filter: 3kLP
Record the test result of frequency modulation deviation in Table A.17.
4) Set the frequency modulation parameter of the signal source according to Table A.17, properly