Icom IC-720A Instruction Manual page 11

This button will allow you to quickly QSY over a great
frequency range.
15. DIAL LOCK BUTTON
After the IC-720A is set to a certain frequency for rag
chewing, mobile operation, etc., pushing the DIAL LOCK
BUTTON will illuminate the DIAL LOCK INDICATOR
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 INDICATOR will go OFF and the fre-
quency will change with the direction of the tuning knob
rotation. Turning the power OFF will release the dial lock
and clear the displayed frequency.
16. TUNING CONTROL KNOB
Rotating the TUNING CONTROL KNOB clockwise іп-
creases the frequency, while rotating it counterclockwise
decreases the frequency. The frequency is changed in 10Hz,
100Hz or 1KHz steps which is according to the TUNING
RATE SELECT switch and the TUNING SPEED BUTTON.
One complete rotation of the tuning knob results in a 1KHz
frequency increase or decrease іп 10Hz steps, 10KHz in
100Н2 steps and 100K Hz in 1K Hz steps.
17. MODE/FREQUENCY DISPLAY
The frequency of the IC-720A is displayed on aluminescent
display tube. Since the 1MHz and 1KHz decimal points are
displayed, the frequency can easily Бе read. The frequencies
indicated are the carrier frequencies of each mode in AM,
USB, LSB and CW. In the RTTY mode, the mark frequency
is displayed.
Remember, if you turn the RIT SWITCH ON to change the
receive frequency and rotate the RIT CONTROL. knob, the
frequency displayed will not change.
The letters shown to the left of the frequency indication
are the initial letter of the operating mode and the letter of
the operating VFO.
18. DIAL LOCK INDICATOR
illuminates when the DIAL LOCK BUTTON is pressed to
lock the dial.
19. DIAL TUNING SPEED (TS) INDICATOR
illuminates when the TUNING SPEED BUTTON is pressed
to set the dial to fast tuning.
20. RIT INDICATOR
Шитіпаїеѕ when RIT is turned ОМ.
21. CW-N (CW NARROW) INDICATOR
Шитіпаїеѕ when the set is іп CW-N mode. This indicator
illuminates not only when the optional CW filter is installed,
but also if it is not installed.
22. TRANSMIT INDICATOR
IIluminates when the transceiver іс in the transmit mode.
23. FUNCTION KEY
Increases the function of the CW and SSB MODE SELECT
switches and the VFO EQUALIZING switch by pushing
this key switch.
24. MODE SELECT SWITCHES
Selects any one of four operating modes by simply pushing
the desired switch. Additionally, the CW and SSB switches
have dual functions as follows.
: For normal CW operation.
: Pushing the FUNCTION key first, then the CW
button, filter is switched to the Narrow CW
filter (when the optional Narrow CW filter is
installed).
CW-N
2. SSB-N : For normal SSB operation, upper sideband
(USB) for 10MHz band and above, and lower
sideband (LSB) for 9MHz band and below.
For reverse SSB operation, lower sideband
(LSB) for 10MHz band and above, and upper
sideband (USB) for 9MHz band and below.
SSB-R :
25. VFO SWITCH
You can select either of the built-in two VFO''s with this
switch. It also selects the relationship of the two МЕО"
with the SIMPLEX/DUPLEX switch. The switch performs
the following operations according to its position.
А. (SIMPLEX) Selects the "А" VFO for both transmit and
receive.
А. (DUPLEX) Selects "А" VFO for receive and "В" VFO
"Тог transmit.
В. (SIMPLEX) Selects the "В" VFO in both transmit апа
receive.
B. (DUPLEX) Selects "В" VFO for receive апа "А" VFO
for transmit.
NOTE: The set will not transmit in the GENERAL COVER
mode.
In addition, when the VFO is switched from "A" VFO to
"Б" VFO, the frequency indicated on the frequency
display just prior to switching goes into a memory inside
the CPU. Thus even if "В" VFO is being used, switching
to "А" again will enable you to operate at the initial
frequency. Switching from "В" to "А" results in the same
Operation.
26. VFO EQUALIZING SWITCH
When "А" VFO апа "В" VFO have different frequencies,
by pushing this switch, "В" VFO will have the same fre-
quency as "А" VFO. This switch has dual functions, by
pushing the FUNCTION key first, then this switch, "А"
VFO will have the same frequency as "В" VFO.
27. RIT SWITCH
Push once for ON; if OFF is desired push the switch again.