
Chapter 7 - Analyzer Mode
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AMA 310/UMS V21.0
7.1
Call-Up and Abort of the Analyzer
The analyzer is called up by pressing the
ANALYZ
key in the basic state of the instrument. Now
the analyzer determines the spectrum in real time over the complete return path frequency range.
The menu item
ABORT
terminates the analyzer and the instrument returns to the basic state.
7.2
Cursor
After calling up the analyzer the cursor (vertical dotted line) is exactly in the center of the spectrum
shown at 35.04 MHz. The cursor can be moved within the display to the left and/or right by the
arrow keys ← and →
. One-time, short pressing of an arrow key moves the cursor by exactly one
pixel on the graphics screen into the desired direction. If an arrow key is pressed longer, the cursor
movement accelerates. The LC display shows the frequency of the current cursor position in MHz.
7.3
Level Display
Apart from the current cursor position, the LC display constantly shows the level measured at this
position. In this level measurement it has to be taken into account that the level shown refers to the
measurement bandwidth corresponding to one pixel of the graphics display (120 kHz). A level
measurement by the cursor is thus only possible for sinusoidal carriers, but not for QAM-modulated
broadband channels.
In the following two representations, all carriers have a level of about 60 dBµV. However, the signal
level in case of the QAM carrier in Figure 7-4 is distributed over a 6.4 MHz bandwidth, whereas in
the sinus case the overall level is concentrated in the discrete carrier.
Please take more detailed information from the Application Note AN005 - Spectrum Analysis. You
can find it on our homepage
→ Support → Application Notes.
Figure 7-3 Level measurement of a sinusoidal carrier with approx. 60 dBµV in the analyzer