ESTeem 195C, Руководство пользователя, Страница: 39 / 75

CHAPTER 6
UTILITIES & FEATURES
Revised: 15 Feb 2017 6-7 ESTeem Models 195MHC
Spectrum Analyzer
A feature of the ESTeem Model 195M/H/C
configuration utility is the spectrum analyzer
found in the Analyzer tab (Figure 12). A spectrum
analyzer is used to visually represent the radio
spectrum around a programmed frequency. The
analyzer displays the signal amplitude on the
vertical axis and the frequency on the horizontal
axis.
The software utility uses the ESTeem Model 195C
or 195M receiver to visually display the radio
activity in the operating frequency band. The
Model 195C can be used to analyze 450 ‐ 470 MHz
frequency band and the 195M can be used for the
150 ‐ 174 MHz frequency. The analyzer has proven
very accurate when compared to the results of a
bench model analyzer.
The software spectrum analyzer has many of the
standard features you would find on a laboratory
grade analyzer. The following is a summary of the
configuration parameters:
Center Frequency – This frequency value can be entered with a keyboard or used as a drop down. The center frequency represents
the center line in the analyzer.
Span – The span is the total frequency
bandwidth show on screen. For example in
Figure 11, the span is set to 5 MHz. The
analyzer is broken up into a 10 x 10 grid. The
total frequency span of 5 MHz would represent
500 KHz (5MHz/10) per division.
Reference Level – The reference level is the
value for the top line of the analyzer. The
reference level in conjunction with adding or
removing external attenuation will allow for
measurements of both small and high power
signals.
Ext Atten – External attenuation. This number
will need to be adjusted if an external
attenuator is used.
Display Line – Displays horizontal line on
screen with signal measurement (Figure 12).
Figure 11: Save and Load Configuration
Figure 12: Marker and Display Line Example