9-3
9
ANTENNA TUNER OPERATION
■
Setting the AT-180 internal switches
The optional AT-180 has 3 operating configurations
for HF band operation. Select a suitable configura-
tions for your antenna system.
q
Remove the top cover of the AT-180.
w
Set the tuner switches to the desired positions ac-
cording to the table below.
SW Position
Operation
S1
A
(default)
The tuner operating mode is set by S2
described below.
B
THROUGH INHIBIT
The tuner tunes the antenna even when
the antenna has poor SWR (up to VSWR
3:1 after tuning). In this case, manual tun-
ing is necessary each time you change
the frequency although the tuner auto-
matically starts tuning when the VSWR
is higher than 3:1. This setting is called
“through inhibit,” however, the tuner is set
to “through” if the VSWR is higher than
3:1 after tuning.
S2
C
TUNER SENSITIVE SETTING
The tuner tunes each time you transmit
(except SSB mode). Therefore, the low-
est SWR is obtained at any given time.
For SSB mode, the same SETTING as
the “D” position.
D
(default)
NORMAL
The tuner tunes when the SWR is higher
than 1.5:1. Therefore, the tuner activates
only when tuning is necessary.
•
Specifications for the AT-180
Frequency coverage
: 1.8–54 MHz
Input impedance
: 50
Ω
Maximum input power
: 120 W
Minimum tuning power
: 8 W
Matching impedance range : 16.7–150
Ω
(HF band)
20–125
Ω
(50 MHz band)
Tuning accuracy
: Less than SWR 1.5:1
Insertion loss
: Less than 1.0 dB
(after tuning)
Power supply requirements : 13.8 V DC/1 A (supplied
from the transceiver’s
ACC socket)
Dimensions (mm/in)
: 167(W)
×
58.6(H)
×
225(D)
6.6(W)
×
2.3(H)
×
8.9(D)
Weight (approx.)
: 2.3 kg; 5.1 lb
Supplied accessories
: Coaxial cable (1 m),
ACC cable (DIN 13 pins)
•
AT-180 inside top cover
S2
S1
D C
B A
•
Connector information for the ACC(2) socket
ACC 2
1
2
3
4
5
6
7
PIN NO./
NAME
DESCRIPTION
q
NC
(8 V*)
(* If the Band Voltage modification is per-
formed, regulated 8 V output. (p. 12-2)) (10
mA max.)
w
GND
Connects to ground.
e
SEND
Input/output pin.
Goes to ground when transmitting
(20 mA max).
When grounded, transmits.
r
NC
(BAND*)
(* If the Band Voltage modification is per-
formed, band voltage output. (p. 12-2))
t
ALC
ALC output voltage (–4 to 0 V).
y
NC
No connection.
u
13.8 V
13.8 V output when power is ON (1 A max).
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