5-2
■
Spectrum scope screen
This DSP-based spectrum scope allows you to dis-
play the frequency and relative signal strength of
received signals on the strengths of signals. The
IC-7700 has two modes for the spectrum display—
one is center mode, and the other is fixed mode.
In addition, the IC-7700 has a mini scope screen to
save screen space.
D
Center mode
Displays signals around the set frequency within the
selected span. The set frequency is always displayed
at the center of the screen.
q
Push
EXIT/SET
several times to close any multi-
function screens, if necessary.
w
Push [SCOPE]
F-1
to select the scope screen.
• Push [WIDE]
F-7
to toggle the screen size be-
tween normal and wide.
e
Push [CENT/FIX]
F-5
to select the center mode.
• “
CENTER
” is displayed when center mode is selected.
r
Push [SPAN]
F-1
several times to select the
scope span.
• ±2.5, ±5.0, ±10, ±25, ±50, ±100 and ±250 kHz are se
-
lectable.
• Hold down [SPAN]
F-1
for 1 second to return to ±2.5
kHz span.
• Sweep speed is selectable for each span independ
-
ently in scope set mode. (pp. 5-5, 5-6)
t
Push [ATT]
F-2
several times to activate an at-
tenuator or turn the attenuator OFF.
• 10, 20 and 30 dB of attenuation is available.
• Hold down [ATT]
F-2
for 1 second to turn OFF the at-
tenuator.
y
Push [MARKER]
F-3
to turn the marker for trans-
mit frequency ON or OFF.
• “
T
” displays the marker at the transmit frequency.
• “<<” or “>>” appears when the marker is out of range.
• The spectrum scope shows the transmit signal while
transmitting. This can be deactivated in scope set
mode. (p. 5-5)
• The spectrum scope shows the peak level hold func
-
tion. Peak levels are displayed in the background of the
current spectrum in a different color until the receive
frequency changes. This can be deactivated and the
waveform color can be set in scope set mode. (p. 5-5)
u
Push [HOLD]
F-4
to freeze the current spectrum
display.
• “
HOLD
” appears while the function is in use.
• The peak hold function can be deactivated in scope set
mode.
i
Push
EXIT/SET
to exit the scope screen.
NOTE:
If a strong signal is received, a ghost signal
may also appear. Push [ATT]
F-2
several times to
activate the spectrum scope attenuator in this case.
Spurious signals may be displayed. They are gen-
erated in the internal scope circuit and do not indi-
cate a transceiver malfunction.
F-2
ATT
F-4
HOLD
F-1
SPAN
F-7
WIDE
F-3
MARKER
F-5
CENT/FIX
EXIT/SET
5
FUNCTIONS FOR RECEIVE
• Scope spurious signal example
Spurious signals may be received on the spectrum
scope screen regardless of the transceiver’s state
(TX or RX). They are generated in the scope circuit.
This does not indicate a transceiver malfunction.
Scope spurious example
• Spectrum scope
Waterfall
