Icom IC-R7O Maintenance Manual page 7

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unnecessary to manually switch OFF the RIT
when changing the operation frequency. The
frequency shift by turning the RIT Control is
not indicated on the frequency display.
RIT SWITCH
Press once for ON; for OFF, press the switch
again.
When the RIT is ON, the RIT INDICATOR will
illuminate. (Note: The RIT wil! also pulse OFF
when the TUNING CONTROL knob is turned.)
NOTCH FILTER SWITCH
Switches the notch filter function ON and OFF.
NOTCH FILTER CONTROL
Shifts the notch filter frequency. Adjust the
control so that the interference is reduced.
P.B. TUNE (PASS BAND TUNING) CONTROL
Ailows continuous tuning of the pass-band
selectivity by moving the filter up to 500Hz
from the upper to lower side in SSB, CW and
RTTY, and 2.7 kHz in AM. Not only improves
selectivity, but also can improve the audio
tone. Normal position is the center (12 o'clock)
or OFF position and is 2.3-kHz wide in SSB,
and 6-kHz wide in AM.
PHONES JACK
Accepts a standard .1/4 inch headphones plug
for headphones of 4 ~ 16 ohms. Stereo
phones can be used without modification.
RECORDER JACK
Accepts a 3.5 mm mini plug for a tape recorder
to record receiving signals. The output is a
fixed level regardless of the position of the AF
GAIN control.
AF GAIN CONTROL
Controls the audio output level. Clockwise
rotation increases the level.
RF GAIN CONTROL
Controls the gain of the RF section. Clockwise
rotation gives the maximum gain. As the
control is rotated counterclockwise, the needle
of the METER rises, and only signals stronger
than the level indicated by the needle will be
heard.
SQUELCH CONTROL
Sets the squelch threshold level. To switch
OFF the squelch function, rotate this control
completely counterclockwise. To set the
threshold level higher, rotate the control clock-
wise.
TONE CONTROL
Controls the receiver audio tone. Adjust the
control to provide comfortable reception.
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S-METER
Signal strength of an incoming signal is indi-
cated on a scale of S1 ~ S9 and S9 to S9 +
AO dB, and a linear scale divided into five.
MUTE INDICATOR
liluminates when the receiver is in the mute
mode for an external transmitter or trans-
ceiver.
SIGNAL INDICATOR
lIluminates when the squelch is opened.
FM TUNING INDICATOR
Iliuminates when the set is tuned to an incom-
ing signal frequency within 1 kHz (when
optional FM unit is installed).
RIT INDICATOR
IIluminates when RIT is switched ON.
MODE/FREQUENCY DISPLAY
The frequency of the IC-R70 is displayed on a
luminescent display tube. Because the 1-MHz
and 1-kHz decimal points are displayed, the
frequency can easily be read. The frequencies
indicated are the carrier frequencies of each
mode in AM, USB, LSB and CW. In the RTTY
mode, the mark frequency (2125 Hz beat tone)
is displayed.
2-2 UNDER THE ACCESS COVER
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MONITOR GAIN SWITCH
Switches the gain of the receiver (monitor) in
the mute mode, High and Low. Set the switch
for comfortable monitoring.
RTTY FILTER SWITCH
Switches the crystal filters, 500 Hz/—6 dB (for
CW) and 2.3 kHz/—6 dB (for SSB) in the RTTY
mode. The selected filter is provided for RTTY
reception when RTTY mode-select switch on
the front panel is pushed.
FREQUENCY SET CONTROL
This control is for fine adjustment of the
reference frequency of the PLL unit, which is
the local oscillator frequency. Do not turn it
unless you want to change the frequency.