Icom IC-7700 - Manual (Page 211)

INSTALLATION NOTES
For amateur base station installations it is recom-
mended that the clearance in front of the antenna array
is calculated relative to the EIRP (Effective Isotropic
Radiated Power). The clearance height below the an-
tenna array can be determined in most cases from the
RF power at the antenna input terminals.
Different exposure limits have been recommended for
different frequencies, a relative table shows a guide-
line 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 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 instal-
lations. The EC recommended limits are almost identi-
cal to the FCC specified ‘uncontrolled’ limits and tables
exist that show pre-calculated safe distances for differ-
ent antenna types for different frequency bands. Fur-
ther information can be found at http://www.arrl.org/.
• Typical amateur radio installation
Exposure distance assumes that the predominant ra-
diation pattern is forward and that radiation downward
is at unity gain (side lobe 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 con-
stant carrier.
For the bands 10 MHz and higher the following power
density limits have been recommended:
10–144 MHz 2 W/sq m
EIRP clearance heights by frequency band
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, EIRP by frequency band
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 transmit-
ter being activated for long periods. (actual recom-
mendation 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 the transmitter after 1–2
minutes etc.
Similarly some types of emission, i.e., SSB, CW, AM
etc. have a lower ‘average’ output power and the as-
sessed risk is even lower.
Versions of the IC-7700 which display the
“CE” symbol on the serial number seal,
comply with the essential requirements of
the European Radio and Telecommunication
Terminal Directive 1999/5/EC.
This warning symbol indicates that this
equipment operates in non-harmonised fre-
quency bands and/or may be subject to li-
censing conditions in the country of use. Be
sure to check that you have the correct ver-
sion of this radio or the correct programming
of this radio, to comply with national licens-
ing requirement.
• List of Country codes (ISO 3166-1)
ABOUT CE
1 Austria AT
2 Belgium BE
3 Bulgaria BG
4 Croatia HR
5 Czech Republic CZ
6 Cyprus CY
7 Denmark DK
8 Estonia EE
9 Finland FI
10 France FR
11 Germany DE
12 Greece GR
13 Hungary HU
14 Iceland IS
15 Ireland IE
16 Italy IT
17 Latvia LV
18 Liechtenstein LI
19 Lithuania LT
20 Luxembourg LU
21 Malta MT
22 Netherlands NL
23 Norway NO
24 Poland PL
25 Portugal PT
26 Romania RO
27 Slovakia SK
28 Slovenia SI
29 Spain ES
30 Sweden SE
31 Switzerland CH
32 Turkey TR
33 United Kingdom GB
Country Codes Country Codes