Icom AH-4 Instructions

Fig.5MOUNTINGEXAMPLES
R DANGER! HIGH VOLTAGE! NEVER touch the antenna while transmitting or tuning. Place the antenna in a position
where you are sure it will not be touched.
AH-2b
antenna element kit
(optional)
Long wire
OPERATION
Tuning is required for each frequency. Be sure to retune
the antenna before transmitting when you change the
frequency— even slightly.
(eg. IC-7300)
q Turn ON the transceiver.
• Each time you push TUNER , "TUNE" is displayed or goes
out, and the AH-4 is turned ON or OFF (bypassed).
w Hold down for 1 second to start manual tuning.
TUNER
• The tuner reduces the SWR to less than 2:1 after 2~3 seconds
of tuning.
LWhile tuning, "TUNE" blinks red.
L If the tuner cannot reduce the SWR to less than 2:1 after 15
seconds of tuning, "TUNE" goes out.
Hold down [TUNER] for 1 second.
SPECIFICATIONS AND OPTIONS
D Specifications
• Frequency range : 3.5–54 MHz (with an antenna longer
than 7 m; 23 ft)
7–54 MHz (with the AH-2b)
• Maximum input power : 120 W
• Input impedance : 50 Ω
• Tuning power required : 5 to15 watts
• Rated voltage : 13.8 V DC ±15%
(current less than 1 A)
• Usable temperature range : –10°C to +60°C (+14°F to +140°F)
• VSWR : 2.0 : 1 or less (except antennas a
one half wave or multiple of a one
half wave in length)
• Weight (approximately) : 1.2 kg (2.65 lb)
• Dimensions : 172(W) × 69.5(H) × 230(D) mm
(projections not included) ; 6.8(W) × 2.7(H) × 9.1(D) inches
 Allspecificationsaresubjecttochangewithoutnoticeorobligation.
1-1-32 Kamiminami, Hirano-ku, Osaka 547-0003, Japan
Dec. 2020
AH-2b + long wire
Long wire
e After tuning, "TUNE" is displayed.
L When the long wire antenna cannot be tuned, "TUNE" goes
out. In that case, the AH-4 is bypassed and the wire is directly
connected.
NOTE:
When the wire antenna cannot be tuned, confirm wire
length and connection. Note that the AH-4 cannot tune a
wire that is a ½λ long or on a multiple of that frequency.
D Options
• OPC-420 shielded control cable
Shielded control cable helps protect the transceiver from RF
feedback and extends separation between tuner and transceiver
up to 10 m. (cable length 10 m; 32.8 ft)
• AH-2b antenna element
A 2.5 m long antenna element for mobile operation with AH-4.
Frequency coverage: 7–54 MHz with the AH-4.
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A8295W-1EX-3 Printed in Japan
© 1997–2020 Icom Inc.
INSTRUCTIONS
HF + 50 MHz AUTOMATIC ANTENNA TUNER
AH-4
Ground terminal
Mounting plate
FEATURES
❍ WIDE TUNING RANGE
The AH-4 provides reliable matching from 3.5 MHz to 54 MHz
when using at least a 7 m (23 ft) antenna; or 7 MHz to 54 MHz
when using the AH-2b antenna element.
❍ AUTOMATIC DIGITAL CONTROL TUNING
The built-in 8-bit microprocessor chooses the lowest SWR using
more than 1,040,000 different LC (coil/capacitor) combinations.
❍ 45 FREQUENCY MEMORIES FOR FAST TUNING
The LC combinations of 45 previously-used frequencies are
automatically memorized. Once a frequency is memorized, the
AH-4 tunes on that frequency in less than 1 second. Note that
the AH-4 does not memorize a frequency which is normally
tuned within 2.5 seconds. Memories are retained only when the
power is on.
SUPPLIED ACCESSORIES
u
q
w
i
e
r
o !0
t
!1
y
Thank you for purchasing the AH-4 HF + 50 MHz
AUTOMATIC ANTENNA TUNER. The AH-4 matches
your transceiver to an antenna more than 7 m/23 ft long
(3.5–54 MHz), or the optional AH-2b (7–54 MHz).
Please read these instructions thoroughly before
installing and operating the AH-4.
DANGER!
R NEVER operate this tuner without a solid ground. Always
connect the ground wire to the ground terminal. DO NOT
use the mounting plate as a ground terminal.
NEVER transmit or tune without an antenna connected.
Failure to use an antenna will damage the tuner.
R HIGH VOLTAGE! NEVER touch the antenna while
transmitting or tuning. Place the antenna in a position where
you are sure it will not be touched.
❍ WEATHERPROOF DESIGN
The AH-4's tightly sealed plastic case allows convenient
mounting virtually anywhere. The AH-4 can be mounted
outdoors under your antenna.
❍ 0.3 W RADIATED POWER
Radiated power during tuning is less than 0.3 W, minimizing
interference to other stations.
✍ NOTE:
The AH-4 can be used with most of Icom HF transceiver,
which covers HF through 50 MHz bands.
However, the IC-706 and IC-736 can only be tuned in the
3.5–30 MHz range.
q U-bolts ...............................................................2
w U-bolt brackets ...................................................2
e Flat washers (M6 large) ..........................................8
r Flat washers (M6 small) ..........................................4
t Spring washers (M6) .............................................8
y Nuts (M6) ............................................................8
u Hex head bolts (M6 × 50) .......................................4
i Self-tapping screws (A0 6 × 30) ..............................4
o PL-259 connectors ................................................2
!0 Weatherproof cap ................................................1
!1 Rubber vulcanizing tape .......................................1
Control cable* (5 m; 16.4 ft) .......................................1
Coaxial cable* (5D-2V: 5 m; 16.4 ft) ..............................1
*Not shown in the illustration to the left.
– 1 –