Chapter IV Operation Guidance
36
Setting of demodulation type: click the “Demodulation Type” in the receiver setting
window or the [Demodulation Type] soft key in the right [Receiver Setting] menu to
select the demodulation type, AM or FM.
Setting of audio filter: click the “Audio Filter” in the receiver setting window or [Audio
Filter] in the right [Receiver Setting] menu. The low-pass, high-pass or band-pass filter
can be selected according to the modulation rate. Optional filter types are as follows:
0.3-20kBP, 0.3-5kBP, 0.3-3kBP, 0.3kHP, 15kLP, 5kLP, 3kLP, 0.3kLP, etc.
Display of measurement results:
The averaging of measurement results can be set according to the stability requirements.
Click the [Average] soft key in the right side of the touch screen, open “Average”, click
the [Averaging Times] soft key in the right side of the touch screen, and the
measurement result will be displayed after averaging according to the set times.
According to the distortion requirements of demodulation results, the SINAD and
distortion measurement are added in the demodulation meter. Distortion measurement is
divided into two types: THD (harmonic distortion) and THD+N (total distortion). The
user can select the type according to the requirements.
Alarm setting: judge whether the measurement result conforms to the requirements. If it
is beyond the range, the alarm color will be displayed to make the judgment more
intuitive. Click “Alarm Setting” in the window, or click the [Alarm Setting] soft key in
the right menu to open the alarm setting window, and set the upper alarm limit and
lower alarm limit. Note that the alarm setting must be within the measurement range
between the upper and lower limit.
5. Frequency modulation deviation
The measurement of frequency modulation deviation with the demodulation meter of 4992A
means the demodulation analysis of the demodulation wave within the IF bandwidth of the
receiver. This is designed for the RF ANT and T/R port. The user can select the appropriate port
for input of the tested signal, according to the power range of the input signal.
Window opening: open the demodulation meter window by pressing the [Transmitter] hard
key or pressing the [Measurement] hard key and setting the instrument menu, and select the
demodulation type “FM” in the receiver setting window that is opened at the same time.
Select the demodulation meter and press the [Full Screen] hard key in the lower part of the
screen to maximize the window, as shown in Fig. 4-10.
Summary of Contents for 4992A
Page 1: ...I 4992A Radio Test Set User Manual China Electronics Technology Instruments Co Ltd...
Page 2: ......
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Page 23: ...Article I Handling Instructions 11 Article I Handling Instructions...
Page 93: ...81 Article II Technical Specifications...
Page 132: ...Article III Maintenance Instructions 120 Article III Maintenance Instructions...
