Icom AH-4 Instructions

q U-bolts .................................................................. 2

w U-bolt plates ......................................................... 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 Control cable (OPC-136; 5 m)............................... 1

!2 Coaxial cable (5D-2V 

× 5 m) ................................. 1

INSTRUCTIONS

HF + 50 MHz AUTOMATIC ANTENNA TUNER

AH-4

Thank you for purchasing the AH-4 AUTOMATIC

ANTENNA TUNER. The AH-4 matches your trans-

ceiver to an antenna more than 7 m/23 ft long (3.5

MHz and above).

Please read these instructions thoroughly before in-

stalling and operating the AH-4.

RNEVER use this tuner when it is ungrounded. Always

ground the tuner through the ground terminal before

operating.  DO NOT use the mounting plates for

grounding.

NEVER transmit or tune without an antenna. Failure to

use an antenna will damage the tuner.

RHIGH VOLTAGE! NEVER touch the antenna while

transmitting or tuning. Place the antenna in a position

where you are sure it will not be touched.

DANGERµ

❍ WIDE TUNING RANGE

The AH-4 provides reliable matching of frequencies

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 condition from more than 1,040,000 different

LC (coil/capacitor) combinations.

❍ 45 FREQUENCY MEMORIES FOR FAST TUNING

The LC combinations of 45 previously-used frequen-

cies are automatically memorized in the AH-4. Once

a frequency is memorized, the AH-4 tunes on that

frequency in less than 1 sec. Note that the AH-4

does not memorize a frequency which is normally

tuned within 2.5 sec. Memories are retained only

when the power is on.

❍ WEATHERPROOF DESIGN

The AH-4’s tightly sealed plastic case allows conve-

nient 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: 50 MHz tuning is possible with the IC-729*,

IC-706MKII, IC-746 and IC-756; the IC-706 and IC-

736 can only be tuned 3.5–30 MHz.

* Connect a 50 MHz antenna connector for 50 MHz

operation.

FEATURES

SUPPLIED ACCESSORIES

Ground terminal

Mounting plate

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