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.
R
NEVER
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.
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.
DANGER
µ
❍
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
q
w
e
r
t
y
u
i
o
!0
