9
67
ANTENNA TUNER OPERATION
■
Optional AT-180
automatic
antenna
tuner
operation
The AT-180 automatic antenna tuner matches the
IC-7200 to the connected antenna automatically.
Once the tuner matches an antenna, the variable
capacitor settings 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.
NOTE:
• The AT-180 can match both HF and 50 MHz
bands. However, operation is different for the HF
and 50 MHz bands.
• When connecting the AT-180, the IC-7200’s out-
put power must be more than 10 W. Otherwise,
the AT-180 may not be tuned correctly. (AT-180’s
minimum operating input power is 8 W.)
CAUTION:
NEVER
transmit with the tuner ON
when no antenna is connected. This will damage
both the transceiver and antenna tuner.
MODE
TUNER
TS
FILTER
SPCH
V/M
A/B
SPLIT
M-CL
SCAN
SET
ATT
P.AMP
COMP
VOX
MNF
RIT
1
2
3
4
5
6
7
8
0
50
28
18
14
10
21
24
=
7
3.5
1.8
F-INP
M-CH/RIT
ENT
BAND
GENE
9
.
AGC
MW
ANF
METER
NR
NB
TUNER
D
Tuner operation
• For the HF band:
Push
TUNER
to turn the tuner ON. The antenna is
tuned automatically during transmission when the
antenna SWR is higher than 1.5:1.
• When the tuner is ON, “
” indication appears.
• For the 50 MHz band:
Push and hold
TUNER
for 1 sec. to tune the antenna.
If
“
”
indicator blinks slowly while transmitting,
push and hold
TUNER
for 1 sec. again to re-tune the
antenna.
D
Manual tuning
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.
Push and hold
TUNER
for 1 sec. to start manual tun-
ing.
• When CW mode is selected, a side tone is emitted, and
“
” indicator blinks; then, the previous mode is se-
lected.
If the tuner cannot reduce the SWR to less than
1.5:1 after 20 sec. of tuning,
“
”
indicator disap-
pears. In this case, check the following:
• the antenna connection and feedline
• the antenna SWR (p. 30; meter function, p. 60;
Measuring SWR)
Through inhibit
(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 in-
hibit,” the tuner will be set to the “through” configura-
tion if the SWR is higher than 3:1 after tuning.
CONVENIENT
• Tuner sensitive condition
(HF bands only)
If you require critical tuning at any time during trans-
mission, select the tuner sensitive condition.
See p. 68 for selection.
• Automatic tuner start
(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. 76 for the automatic tuner
function.
• PTT tune function
(p. 76)
The AT-180 is tuned when [PTT] is pushed after the
frequency is changed (more than 1%) if the AT-180 is
turned ON. This function removes the “push and hold
TUNER
” operation and activates first transmission
on the new frequency.
This function is turned ON in the set mode.