Icom AH-4 Instructions

Fig.6 MOUNTING EXAMPLES
AH-2b
antenna element kit
tional)
Long wire
OPERATION
Tuning is required for each frequency. Be sure to retune
the antenna before transmitting when you change the fre-
quency— even slightly.
(eg. IC-7000)
Set the desired frequency in an amateur band.
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• The AH-4 will not operate on frequencies outside of ham
bands.
Hold down [TUNER/CALL] for 1 seconds.
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• " " indicator appears while tuning.
Hold down [TUNER/CALL] for 1 second.
CALCULATION OF UNDESIRABLE ANTENNA LENGTHS
300 1
Length of
(½ λ) = ×
Operating frequency (MHz) 2
half wave

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
All specifications are subject to change without notice or obligation.
1-1-32 Kamiminami, Hirano-ku, Osaka 547-0003 Japan
AH-2b + long wire
(op-
Long wire
e " " indicator stays ON when tuning is complete.
• When the antenna cannot be tuned, " " indicator blinks,
and the AH-4 is bypassed and the antenna is directly connected
to the antenna connector on the transceiver.
To manually bypass the AH-4, push [TUNER/CALL].
r
[EXAMPLE] Antenna lengths to avoid when operating at 29.00
MHz
1
300
Multiple
×
× (1, 2, 3...) = 5.2, 10.3, 15.5 m
=
2
of ½ λ 29
D Options
• OPC-420
shielded control cable
Shielded control cable helps protect the transceiver from RF feed-
back 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. Fre-
quency coverage: 7–54 MHz with the AH-4.
A-8295H-1EX-w Printed in Japan
© 1997–2012 Icom Inc.
INSTRUCTIONS
HF + 50 MHz AUTOMATIC ANTENNA TUNER
AH-4
DANGER!
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 auto-
matically 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 AU-
TOMATIC 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.
RNEVER 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. Fail-
ure to use an antenna will damage the tuner.
RHIGH VOLTAGE! NEVER touch the antenna while trans-
mitting 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 mount-
ing 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 inter-
ference 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.
U-bolts ...............................................................2
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U-bolt brackets ...................................................2
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Flat washers (M6 large) ..........................................8
e
r Flat washers (M6 small) ..........................................4
t Spring washers (M6) .............................................8
Nuts (M6) ............................................................8
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Hex head bolts (M6 × 50) .......................................4
u
× 30) ..............................4
i Self-tapping screws (A0 6
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.