1
1
ANTENNA SYSTEM
n Antenna for ship
Required antenna element length
Required antenna element length to achieve full per-
formance varies according to the lowest frequency:
The lowest frequency Required antenna element length
1.6 MHz band 7 m; 23.0 feet or longer
4 MHz band 3 m; 9.8 feet or longer
The longer the antenna element, the better the an-
tenna efficiency.
Undesirable antenna element lengths
DO NOT use an antenna element such as multi-
ples of
1
⁄2λ lengths (half wavelength), since tuning be-
comes difficult.
L : Antenna element length to be avoided [m]
f : Operating frequency [MHz]
n : Natural number (n = 1, 2, 3, ...)
[Example]
At an operating frequency of 16 MHz, avoid the fol-
lowing antenna element lengths:
L =
300
16
×
1
2
n
×
9.4, 18.8, ...
1 m
39 inches
For example, if 15 m (49.2 feet) is selected for an
antenna element length, you have no problem in the
1.6–25 MHz marine bands range.
Insulator
Backstay operates as
a long-wire antenna.
Insulator
Whip antenna
NOTE: Keep antennas as far away from other ob-
jects as possible, especially metal objects.
n Antenna for land operation
In some countries, HF transceivers can be used for
land mobile operation. Ask your Icom Dealer for de-
tails, since the radio law varies according to coun-
tries.
For land mobile operation on 4 MHz or above, an
optional AH-2b
a n t e n n a e l e m e n t is available. The
AH-2b includes a sturdy tow hook mount system for
holding a 2.5 m (8.2 feet) stainless steel antenna ele-
ment plus all the necessary hardware.
Refer to the AH-2b instruction manual for the AH-2b
and AT-130/E installation to your vehicle. Ask your
Icom Dealer for details.
Connect a suitable antenna element for a coastal sta-
tion. To achieve full performance, refer to “Required
antenna element length” above.