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15
OPTION UNIT INSTALLATIONS AND SETTINGS
■
AT-180 internal switch description
The optional AT-180 has 3 operating conditions for HF
band operation. Select a suitable condition according
to 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.
•
Specifications for the AT-180
• Frequency coverage : 1.9 – 54 MHz
• Input impedance
: 50
Ω
• Maximum input
: 120 W
power
• Minimum tuning
: 8 W
power
• Matching impedance : 16.7–150
Ω
(HF band)
range
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
: 13.8 V DC/1 A
(supplied from
requirements
the transceiver’s ACC socket)
• Dimensions
(mm/in)
: 167(W)
×
58.6(H)
×
225(D)
6
9
⁄
16
(W)
×
2
5
⁄
17
(H)
×
8
7
⁄
8
(D)
• Weight
: 2.4 kg; 5 lb 4 oz
• Supplied accessories : coaxial cable
(1 m)
,
ACC cable
(DIN 13 pins)
•
AT-180 inside top cover
•
Connector information for ACC(2) socket
S2
S1
D C
B A
ACC 2
1
2
3
4
7
6
5
PIN NO./
NAME
DESCRIPTION
q
8 V
Regulated 8 V output.
(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
BAND
Band voltage output.
(Varies with amateur band; 0 to 8.0 V).
t
ALC
ALC output voltage (–4 to 0 V).
y
NC
No connection.
u
13.8V
13.8 V output when power is ON (1 A max).
SW Position
Operation
S1
A
(default)
The tuner operating condition 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 tuning is
necessary each time you change the fre-
quency although the tuner automatically
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 CONDITION
The tuner tunes each time you transmit (ex-
cept SSB mode). Therefore, the lowest
SWR is obtained at any given time.
For SSB mode, the same condition as the
“D” position.
D
(default)
NORMAL CONDITION
The tuner tunes when the SWR is higher
than 1.5:1. Therefore, the tuner activates
only when tuning is necessary.