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PANEL DESCRIPTION
1-5
!5
PREAMP•ATTENUATOR KEY
P.AMP
ATT
❍
PREAMP KEY Operation (p. 5-2)
(Frequency band: HF, 50/70 MHz)
Push to select one of two receive RF preampli-
fiers, or to bypass them.
• “P. AMP1” is a wide dynamic range preamplifier. It is
most effective for the 1.8 to 21 MHz bands.
• “P. AMP2” is a high-gain preamplifier. It is most effec
-
tive for the 24 to 70 MHz bands.
• No indicator appears when the preamplifiers are not
selected.
✔
What is the preamplifier?
The preamplifier amplifies signals in the front end
to improve the S/N ratio and sensitivity. Select “P.
AMP1” or “P. AMP2” when receiving weak sig-
nals.
(Frequency band: 144/430 MHz)
Push to turn the preamplifier ON or OFF.
• “P.AMP” appears when the preamplifier is ON.
❍
ATTENUATOR KEY Operation (p. 5-2)
➥
Hold down for 1 second to turn ON the attenu-
ator.
• “ATT” appears when the attenuator is ON.
➥
Push to turn OFF the attenuator.
• “ATT” disappears.
✔
What is the attenuator?
The attenuator prevents a desired signal from be-
ing distorted when very strong signals are near it,
or when very strong electromagnetic fields, such
as from a broadcasting station, are near your lo-
cation.
!6
NOTCH KEY
NOTCH
(Mode = Auto notch: SSB/AM/FM
Manual notch: SSB/CW/RTTY/AM)
➥
In the SSB and AM modes, push to toggle the
notch function between auto, manual and OFF.
• Either the Auto or Manual notch function can be turned
OFF in the “[NOTCH] Switch (SSB)/(AM)” items of the
“Function” Set mode. (p. 17-21)
SET
> Function >
[NOTCH] Switch (SSB)
SET
> Function >
[NOTCH] Switch (AM)
➥
In
the
FM mode, push to turn the Auto Notch func-
tion ON or OFF.
➥
In
the
CW or RTTY mode, push to turn the Manual
Notch function ON or OFF.
• “MN” appears when the Manual Notch function is
ON.
• “AN” appears when the Auto Notch function is ON.
• No indicator appears when the notch filter is OFF.
➥
Hold down for 1 second to display the “NOTCH”
screen.
Push to return to the previous screen.
• Rotate the Dial to adjust the notch frequency to reject
an interfering signal when the manual function is ON.
• Notch filter center frequency:
SSB/RTTY: –1040 Hz to +4040 Hz
CW:
CW pitch frequency –2540 Hz to
CW pitch fre2540 Hz
AM:
–5060 Hz to +5100 Hz
✔
What is the notch filter?
The notch filter is a narrow filter that eliminates un-
wanted CW or AM carrier tones, while preserving
the desired voice signal. The DSP circuit automati-
cally adjusts the notch frequency to effectively elimi
-
nate unwanted tones.
Controller — Front panel (Continued)
PBT
RIT
TX / RX
PWR
AF
RF/SQL
CLR
M-CH
BANK
RIT
TUNER/CALL
MENU
MIC/RF PWR
NB
SPEED/PITCH
SET
QUICK
NOTCH
DR
AUTO TUNE RX
�
CS
XFC
SPEECH
MPAD
NR
P.AMP ATT
i7100
!6
!5
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