Icom AT-130 Instruction Manual page 4

1 ANTENNA SYSTEM
Antenna for ship
Required antenna element length
Required antenna element length to achieve full perform-
ance varies according to the lowest frequency:
Required antenna element length The lowest frequency
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 antenna
efficency.
Undesireable antenna element lengths
AVOID multiples of 1/2 (half wavelength) for antenna
element lengths, since tuning becomes difficult.
L : Antenna element length to be avoided [m]
f : Operating frequency [MHz]
n : Natural number (n= 1, 2, 3, ...)
1
= .
L=
xn
[Example]
At an operating frequency of 16 MHz, avoid the following
antenna element lengths:
300 1
L= —— x— Xn 94, 188...
16 2
1m = 39inches
For example, if 15 m is selected for an antenna element
length, you have no problem in 1.6—25 MHz marine
bands.
W Antenna for land operation
In some countries, HF transceivers can be used for land
mobile operation. Ask your Icom Dealer for details, since
the radio law varies according to countries.
For land mobile operation on 4 MHz and above, an
optional AH-2b ANTENNA ELEMENT is available. The
AH-2b includes a sturdy tow hook mount system for
holding a 2.5 m; 8.2 feet stainless steel antenna element
plus all the necessary hardware.
NOTE: Keep antennas as far away from other objects as
possible, especially metal objects.
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 station,
To achieve full performance, refer to "Required antenna
element length" above,