Icom I706MKTMG AT-180internal switch description, S2 S1 D C BA, •AT-180inside top cover, Pin No

OPTIONAL INSTALLATIONS/SETTINGS 10

■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.

➀Remove the top cover of the AT-180.

➁Set the tuner switches to the desired positions according to the table below.

SW Position Operation

AThe tuner operating condition is set by S2 (default) described below.

	THROUGH INHIBIT
	The tuner tunes the antenna even when
	the antenna has poor SWR (up to VSWR
S1	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
C	(except SSB mode). Therefore, the lowest
	SWR is obtained at any given time.
S2	For SSB mode, the same condition as the
	“D” position.

NORMAL CONDITION

DThe tuner tunes when the SWR is higher (default) than 1.5:1. Therefore, the tuner activates

only when tuning is necessary.

•AT-180 inside top cover

S2 S1

D C B A

•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 –125Ω (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) 69⁄16(W) ⋅ 25⁄17(H) ⋅ 87⁄8(D)

• Weight : 2.4 kg; 5 lb 4 oz

•Supplied accessories : coaxial cable (1 m), ACC cable (DIN 13 pins)

•Connector information for ACC(2) socket

4	2
	5
1	3 ACC 2
6	7

PIN NO./	DESCRIPTION
NAME
➀8 V	Regulated 8 V output.
	(10 mA max.)
➁GND	Connects to ground.
➂SEND	Input/output pin.
	Goes to ground when transmitting (20 mA
	max). When grounded, transmits.
➃BAND	Band voltage output.
	(Varies with amateur band; 0 to 8.0 V).
➄ALC	ALC output voltage (–4 to 0 V).
➅ NC	No connection.
➆ 13.8V	13.8 V output when power is ON (1 A max).

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