ICOM IC-706MKIIG User Manual
27
4
RECEIVE AND TRANSMIT
The AT-180 automatic antenna tuner matches the IC-
706MKIIG to the connected antenna automatically.
Once the tuner matches an antenna, the variable
capacitor angles are memorized as a preset point for
each frequency range (100 kHz steps). Therefore,
when you change the frequency range, the variable
capacitors are automatically preset to the memorized
point.
706MKIIG to the connected antenna automatically.
Once the tuner matches an antenna, the variable
capacitor angles are memorized as a preset point for
each frequency range (100 kHz steps). Therefore,
when you change the frequency range, the variable
capacitors are automatically preset to the memorized
point.
N
No
otte
e::
• The AT-180 cannot be used for the 144/430 MHz
band.
• When operating on the 144/430 MHz band, push-
ing the tuner switch selects the call channel (p. 39).
• The AT-180 can match both HF and 50 MHz bands.
However, operation is different for the HF and 50
MHz bands.
MHz bands.
T
TU
UN
NE
ER
R O
OP
PE
ER
RA
AT
TIIO
ON
N
• F
Fo
orr tth
he
e H
HF
F b
ba
an
nd
d::
Push [TUNER] to turn the tuner ON. The antenna is
tuned automatically during transmission when the
antenna SWR is higher than 1.5:1.
tuned automatically during transmission when the
antenna SWR is higher than 1.5:1.
• When the tuner is OFF, the [TUNER] light goes out.
• F
Fo
orr tth
he
e 5
50
0 M
MH
Hz
z b
ba
an
nd
d::
Push and hold [TUNER] to tune the antenna. If the
[TUNER] light flashes slowly while transmitting, push
and hold [TUNER] again to re-tune the antenna.
[TUNER] light flashes slowly while transmitting, push
and hold [TUNER] again to re-tune the antenna.
M
MA
AN
NU
UA
AL
L T
TU
UN
NIIN
NG
G
During SSB operation on HF bands at low voice lev-
els, the AT-180 may not be tuned correctly. In such
cases, manual tuning is helpful.
els, the AT-180 may not be tuned correctly. In such
cases, manual tuning is helpful.
Push and hold [TUNER] for 1 sec. to start manual tun-
ing.
ing.
• CW mode is selected, a side tone is emitted, and the
[TUNER] light flashes; then, the previous mode is select-
ed.
ed.
If the tuner cannot reduce the SWR to less than 1.5:1
after 20 sec. of tuning, the [TUNER] light goes out. In
this case, check the following:
• the antenna connection and feedline
• the antenna SWR (p. 26; meter function)
after 20 sec. of tuning, the [TUNER] light goes out. In
this case, check the following:
• the antenna connection and feedline
• the antenna SWR (p. 26; meter function)
T
Th
hrro
ou
ug
gh
h iin
nh
hiib
biitt (HF bands only)
The AT-180 has a through inhibit condition. When
selecting this condition, the tuner can be used at
poor SWR’s. In this case, automatic tuning in the HF
bands activates only when exceeding SWR 3:1.
Therefore, manual tuning is necessary each time you
change the frequency. Although termed “through
inhibit,” the tuner will be “through” if the SWR is high-
er than 3:1 after tuning.
selecting this condition, the tuner can be used at
poor SWR’s. In this case, automatic tuning in the HF
bands activates only when exceeding SWR 3:1.
Therefore, manual tuning is necessary each time you
change the frequency. Although termed “through
inhibit,” the tuner will be “through” if the SWR is high-
er than 3:1 after tuning.
• T
Tu
un
ne
err s
se
en
ns
siittiiv
ve
e c
co
on
nd
diittiio
on
n (HF bands only)
If you require critical tuning at any time during trans-
mission, select the tuner sensitive condition. See
p. 55 for selection.
mission, select the tuner sensitive condition. See
p. 55 for selection.
• A
Au
utto
om
ma
attiic
c ttu
un
ne
err s
stta
arrtt (HF bands only)
If you want to turn OFF the tuner under conditions of
VSWR 1.5:1 or less, use “automatic tuner on” and
turn the tuner OFF. See p. 54 for turning the function
ON and OFF.
VSWR 1.5:1 or less, use “automatic tuner on” and
turn the tuner OFF. See p. 54 for turning the function
ON and OFF.
D O
Op
pttiio
on
na
all A
AT
T--1
18
80
0
A
AU
UT
TO
OM
MA
AT
TIIC
C A
AN
NT
TE
EN
NN
NA
A T
TU
UN
NE
ER
R
o
op
pe
erra
attiio
on
n
[TUNER/CALL]
Lights to indicate the AT-180
is turned ON.
is turned ON.
[TUNER/CALL]
Flashes to indicate re-tuning
is necessary.
is necessary.
C
CA
AU
UT
TIIO
ON
N::
N
NE
EV
VE
ER
R transmit with the tuner ON
when no antenna is connected. This will damage
both the transceiver and the antenna tuner.
both the transceiver and the antenna tuner.
[TUNER/CALL]
Push and hold for 1 sec. to start
manual tuning.
manual tuning.
CONVENIENT
IC-706MKIIG.qxd 02.3.27 13:53 Page 27