18
4.3.3. SPECTRUM Measurement Mode
The
icon in the main menu refers to this mode. This mode displays the signal
spectrum. See figure 4.5 for the representation of the screen view:
Figure 4.5
Index 3 shows the signal level in the frequency point (value is displayed in index 1)
indicated by the marker (index 4). The marker is represented as a vertical dashed line. The
scan span limits by frequency are indicated in positions indexed 2 and 5.
You can navigate the marker by means of
«
◄
»
and
«
►
»
keys.
You can select any of the four parameters of the spectrum display by the functional
keys, and then set it by
« »
and
« »
keys.
To select the reference level press
«F1». Ref.lev. = 0 dB
message will appear on the
screen. Using
« »,
« »
arrows set the displayed level scale shift. If the automatic
selection mode of reference level is enabled (section 4.3.10),
Auto mode
message will
appear on the screen.
The level scale parameter is set by «
F2»
key
. Scale = 10 dB/Div
message will appear.
Use
« »,
« »
arrows to select the scale division from the available values
5
,
10
and
20
dB/Div.
To set the scanning start press «
F3»
key
. Start = 50 MHz
message will appear. Use
« »
and
« »
arrows to select the start of the sweep with 5 MHz step.
To set the frequency scale press «
F4». Span = 2 MHz/Div
message will appear. Using
« »,
« »
arrows select the scale division from the available values
2
,
4
,
8
,
16
MHz/Div.
The scanning span will be 14, 28, 56, 112 MHz correspondingly.
You can enter the scan start frequency using the alphanumeric keypad. After you have
set the frequency in MHz, press
«MENU/ENTER»
. In case the new value is incorrect, the
previous value will be restored after you pressed
«MENU/ENTER»
key. To set scan start
frequency by channels, press
«
С
»
key and enter the channel number. Press
«MENU/ENTER»
and the marker will move to the video carrier frequency point of the
selected channel.
If you select the frequency scale division greater than 2 MHz/Div, more than one
frequency point will be displayed in one column of the spectrogram, as the sweep step is
always 125 kHz. In this case the higher magnitude will be reported on the screen.
4.3.4. SCAN Measurement Mode
The
icon in the main menu refers to this mode. This mode displays the signal
levels as a bar-graph. The screen view is presented in figure 4.6:
Figure 4.6
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