Antenna System; Antenna For Ship - Icom AT-141 Instruction Manual

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ANTENNA SYSTEM

Antenna for ship

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D 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
4 MHz band
The longer the antenna element, the longer commu-
nication distance.
D Undesirable antenna element lengths
DO NOT
use an antenna element such as mul-
λ lengths (half wavelength), since tuning
tiples of 1 ⁄
2
becomes difficult.
L : Undesirable antenna element length [m]
f : Operating frequency [MHz]
n : Natural number (n = 1, 2, 3, ...)
300 1
L = × ×
n
f 2
[Example]
At an operating frequency of 16 MHz, avoid the fol-
lowing antenna element lengths:
300 1
L = × × n
16 2
For example, if 15 m is selected for an antenna ele-
ment length, you have no problem in the 1.6 to 25
MHz marine bands range.
3 3
7 m; 23.0 feet or longer
3 m; 9.8 feet or longer
9.4, 18.8, ...
Insulator
Backstay operates as
a long-wire antenna.
Insulator
NOTE: Keep antennas as far away from other ob-
jects as possible, especially metal objects.
Whip antenna