Icom IC-701 Instruction Manual page 10

OFF the RIT when changing operating frequency. The
frequency shift by tuning the RIT Control is not indicated
on the frequency display.
15. RIT SWITCH
This is a spring-loaded switch for the RIT control. To
turn ON the RIT, push down once. If OFF is desired, push
down again. When the RIT is ON the LED above the RIT
control knob is lit. This also indicates the center position
of the RIT control. With the RIT circuit OFF the LED
is also OFF. Also if the RIT is ON and the Tuning Knob
is rotated one increment it will pulse the RIT OFF unless
the internal jumper has been changed.
16. NB (NOISE BLANKER) SWITCH
When pulse type noise such as automobile ignition noise is
present, set this switch to the ON (down) position. The
noise will be reduced to provide comfortable reception.
17. AGC (AUTOMATIC GAIN CONTROL) SWITCH
With this switch you can change the time constant on the
AGC circuit. With the switch in the AGC (up) position,
the circuit operates as a '"hang'' AGC and maintains the
AGC voltage for a specific time, thus it is suitable for SSB
reception. With the switch in the FAST (down) position,
the circuit is OFF, and AGC is suitable for stations suffering
from fast fading or operating in the CW mode.
18. TRANSMIT/RECEIVE (T/R) SWITCH
This switch is for manually switching from transmit to
receive and vice versa. Set the switch to RECEIVE (up)
and the !C-701 is in the receive mode. Set the switch to
TRANSMIT (down) and it switches to transmit. When
switching with the PTT switch on the microphone or with
the VOX switch set to ON the T/R switch must be in the
RECEIVE position.
19. VOX SWITCH
This switches the VOX circuit ON and OFF. When it is
in the ON (down) position, in SSB, T/R switching is
accomplished by means of a voice signal. !n CW operation,
semi-break-in switching by means of keying is possible.
20. ATT (ATTENUATOR) SWITCH
Turn the ATT switch ON (down) when strong nearby
signals disturb signal reception or make "'S" readings
difficult. in the ON position, a 10dB attenuator is inserted
into the receiving antenna circuit, reducing interfering
signals and giving more stable reception. In normal
operation the ATT switch is left in the OFF (up) position.
21. TUNING CONTROL KNOB
Rotating the TUNING CONTROL KNOB clockwise in-
creases the frequency, while rotating it counter-clockwise
decreases the frequency. The frequency is changed in
100Hz steps which correspond to the smaller vernier
marks on the knob. The larger marks represent 1KHz
steps. One complete rotation of the tuning knob results in
a 5KHz frequency increase or decrease in 100Hz steps
exactly as shown by the small vernier marks.
22. TUNING SPEED BUTTON
Pushing the TUNING SPEED BUTTON will illuminate the
DIAL FAST display LED, and the small vernier marks on
the tuning knob are changed to correspond to 10KHz steps.
At the same time, the 1KHz and 100Hz digits are cleared
on the display to show '0.0'... When the Tuning Speed
Button is depressed again, the dial fast display LED goes
OFF and the small vernier marks will again correspond to
100Hz steps. This button will allow you to quickly QSY
over a great frequency range.
23. DIAL LOCK BUTTON
After the IC-701 is set to a certain frequency for rag
chewing, mobile operation, etc., pushing the DIAL LOCK
BUTTON will illuminate the DIAL LOCK display LED
and the VFO is electronically locked at the displayed
frequency, thus inactivating the operation of the tuning
knob. To change frequency, the dial lock must first be
disengaged by pushing the dial lock button again. The dial
lock display LED will go OFF and the frequency will
change with the direction of the tuning knob rotation.
Turning the power OFF will release the dial lock and clear
the displayed frequency.
24. FREQUENCY DISPLAY
The frequency of the IC-701 is displayed on 7 segment
LEDs. Since the 1MHz and 1KHz decimal points are
displayed, the frequency can easily be read. The fre-
quencies indicated are the carrier frequencies of each mode
in USB, LSB and CW. In the RTTY mode, the space
frequency is displayed. Since the local oscillation frequency
is shifted in accordance with modes, no tuning will be
required if you change modes. Remember, if you turn
the RIT control ON to change the receive frequency and
rotate the RIT control knob, the frequency displayed will
not change.
25. TRANSMIT INDICATOR LED
When your set is in the transmit mode, this LED is lit.
26. DIAL TUNING SPEED INDICATOR LED
illuminates when the TUNING SPEED BUTTON is pressed
to set the dial to fast tuning.
27. DIAL LOCK INDICATOR LED
illuminates when the DIAL LOCK BUTTON is pressed
to lock the dial.
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