Icom IC-7600, Instruction Manual, Page: 186 / 196

15
177
CE
INSTALLATION NOTES
For amateur base station installations it is
recommended that the forward clearance in front of
the antenna array is calculated relative to the EIRP
(Effective Isotropic Radiated Power). The clearance
height below the antenna array can be determined in
most cases from the RF power at the antenna input
terminals.
As different exposure limits have been recommended
for different frequencies, a relative table shows a
guideline for installation considerations.
Below 30 MHz, the recommended limits are specified
in terms of V/m or A/m fields as they are likely to fall
within the near-field region. Similarly, the antennas
may be physically short in terms of electrical length
and that the installation will require some antenna
matching device which can create local, high intensity
magnetic fields. Analysis of such MF installations
is best considered in association with published
guidance notes such as the FCC OET Bulletin 65
Edition 97-01 and its annexes relative to amateur
transmitter installations.
The EC recommended limits are almost identical to
the FCC specified ‘uncontrolled’ limits and tables exist
that show pre-calculated safe distances for different
antenna types for different frequency bands. Further
information can be found at http://www.arrl.org/.
• Typical amateur radio installation
Exposure distance assumes that the predominant
radiation pattern is forward and that radiation
vertically downwards is at unity gain (sidelobe
suppression is equal to main lobe gain). This is true
of almost every gain antenna today. Exposed persons
are assumed to be beneath the antenna array and
have a typical height of 1.8 m.
The figures assume the worst case emission of a
constant carrier.
For the bands 10 MHz and higher the following power
density limits have been recommended:
10–50 MHz 2 W/sq m
Vertical clearance by EIRP output
1 Watts
2.1 m
10 Watts 2.8 m
25 Watts 3.4 m
100 Watts 5 m
1000 Watts 12 m
Forward clearance by EIRP output
100 Watts
2 m
1000 Watts 6.5 m
10,000 Watts 20 m
100,000 Watts 65 m
In all cases any possible risk depends on the
transmitter being activated for long periods. (actual
recommendation limits are specified as an average
during 6 minutes) Normally the transmitter is not
active for long periods of time. Some radio licenses
will require that a timer circuit automatically cuts off
the transmitter after 1–2 minutes etc.
Similarly some modes of transmission, SSB, CW,
AM etc. have a lower ‘average’ output power and the
assessed risk is even lower.
• List of Country codes (ISO 3166-1)
Country Codes Country Codes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Austria
Belgium
Bulgaria
Croatia
Czech Republic
Cyprus
Denmark
Estonia
Finland
France
Germany
Greece
Hungary
Iceland
Ireland
Italy
Latvia AT
BE
BG
HR
CZ
CY
DK
EE
FI
FR
DE
GR
HU
IS
IE
IT
LV
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33 Liechtenstein
Lithuania
Luxembourg
Malta
Netherlands
Norway
Poland
Portugal
Romania
Slovakia
Slovenia
Spain
Sweden
Switzerland
Turkey
United Kingdom LI
LT
LU
MT
NL
NO
PL
PT
RO
SK
SI
ES
SE
CH
TR
GB