Icom IC-7851 Instruction Manual page 125

6
SCOPE OPERATION
■
Spectrum scope screen (Continued)
D Adjusting the Reference level
When monitoring a weak signal that is buried in the
noise floor, or monitoring a strong signal but some
stronger signals is nearby, adjust the Reference level
of the screen helps to see these signals.
• Even if this setting is changed, it does not affect the
scope input level.
If you want to change the scope input level, set the
Scope attenuator of
10 dB, 20 dB, or 30 dB
• When you adjust the Reference level, the signal
strength for the waterfall also appears to change.
q Display the
Spectrum scope
[<MENU1>](F).
SCOPE [F-1]  <MENU1> [F-1]  Displays <MENU2>
• The function menu changes to Menu 2.
w
Push [REF](F).
• Displays the Reference level window.
• Push again to close the window.
e
Rotate [MAIN DIAL] to adjust the level.
• Adjustable range: –20.0 dB ~ +20.0 dB.
• Hold down [REF](F) for 1 second to select ±0.0 dB.
r
Push [REF](F).
t To exit the Spectrum scope screen, push [EXIT/SET].
.
screen, then push
6-8
(F) Function keys
• Function menu (MENU2)
• Reference level (±0.0 dB)
• Difference spectrum (+20.0 dB, ±0.0 dB, –20.0 dB)
Reference level
(+20.0 dB)
ATT OFF M S T
–5.0k
+20.0 dB
±0.0 dB
–20.0 dB
–4
• Display example (+20.0 dB)
All signal levels appear stronger.
• Display example (–20.0 dB)
All signal levels appear weaker.
[EXIT/SET] [MAIN DIAL]
Reference level
(–20.0 dB)
SPECTRUM SCOPE
HOLD ATT OFF M S T
–5.0k
–3 –2 –1 –4 0
SPECTR
HOLD
CENTER MAIN
–3 +1 –2 +2 –1 +3