DEVA Broadcast Radio Explorer II, Инструкция по техническому обслуживанию и эксплуатации

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E-mail: office@devabroadcast.com ,Web: www.devabroadcast.com
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Parameter Control States:
Source – The signal source to be calculated and visualized is chosen from the Signal section
placed on the right bottom corner of the data plot. The sources to be chosen from are as follows -
RF, MPX, Left and Right.
RF Input – Select the active antenna input.
Average – indicates buffer numbers taken included in the calculation and obtaining of the
average signal. The possible values of the parameter are: 1 (no average), 5, 10, 20, 50, Infinite.
Frequency – sets/indicates the tuned frequency.
Window – sets the Window Function to be used in order for the FFT to be calculated. The FFT
based measurements are subject to errors from an effect known as spectral leakage, which occurs
when the FFT is computed from of uninterrupted data block. This problem could be minimized
by applying the appropriate windowing function. Depending on the specific application, the
appropriate window function should be applied. Errors may be introduced in the FFT amplitude,
frequency or overall shape of the spectrum if the windowing is not correctly applied.
The available windows and their features are given below. This table can be used to choose the
best windowing function for each application.
Window
Best type for
these Signal
Types
Frequency
Resolution
Spectral Leakage
Amplitude
Accuracy
Rectangle
Transient &
Synchronous
Sampling
Best Poor Poor
Barlett Random Good Fair Fair
Blackman Random or mixed Poor Best Good
Hamming Random Good Fair Fair
Von Hann Random Good Good Fair
Flat-top Sinusoids Poor Good Best