At-180 Internal Switch Description - Icom IC-718 Instruction Manual

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.
Remove the top cover of the AT-180.
Set the tuner switches to the desired positions
according to the table below.
SW Position
The tuner operating condition is set by S2
A
(default)
described below.
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
B
frequency 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.
TUNER SENSITIVE CONDITION
The tuner tunes each time you transmit
(except SSB mode). Therefore, the lowest
C
SWR is obtained at any given time.
For SSB mode, the same condition is as
the "D" position below.
NORMAL CONDITION
The tuner tunes when the SWR is higher
D
(default)
than 1.5:1. Therefore, the tuner activates
only when tuning is necessary.
• Specifications for the AT-180
• Frequency coverage : 1.9 – 54 MHz
• Input impedance : 50
• Maximum input : 120 W
power
• Minimum tuning : 8 W
power
• Matching impedance : 16.7–150
range 20 –125
• 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
requirements
the transceiver's ACC socket)
• Dimensions : 167(W) 58.6(H) 225(D)
(mm/in)
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6
• Weight : 2.4 kg; 5 lb 4 oz
• Supplied accessories : coaxial cable
ACC cable
Operation
(HF band)
(50 MHz band)
(supplied from
5 7
⁄ (W) 2 ⁄ (H) 8 ⁄ (D)
16 17 8
,
(1 m)
(DIN 13 pins)
INSTALLATION AND CONNECTIONS
• AT-180 inside top cover
S2 S1
D C B A
• Connector information for ACC(2) socket
2
5
4
3 ACC 2
1
6 7
PIN NO./
DESCRIPTION
NAME
Regulated 8 V output.
8 V
(10 mA max.)
GND
Connects to ground.
Input/output pin.
SEND
Goes to ground when transmitting (20 mA
max). When grounded, transmits.
Band voltage output.
BAND
(Varies with amateur band; 0 to 8.0 V).
ALC
ALC output voltage (–4 to 0 V).
NC
No connection.
13.8V
13.8 V output when power is ON (1 A max).
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