Rf Field Exposure; Electromagnetic Compatibility - Yaesu FT-847 Operating Manual

Installation
RF F
This transceiver is capable of power output in excess
of 50 Watts, so customers in the United States may be
required to demonstrate compliance with Federal Com-
munications Commission (FCC) regulations concern-
ing maximum permissible exposure to radio frequency
energy. Compliance is based on the actual power out-
put used, feedline loss, antenna type and height, and
other factors which can only be evaluated as a system.
Information regarding these regulations may be avail-
able from your Dealer, your local radio club, from the
FCC directly (press releases and other information can
be found on the FCC's site on the World Wide Web at
<http://www.fcc.gov>), or from the American Radio
Relay League, Inc. (225 Main St., Newington CT
06111 or <http://www.arrl.org>).
Although there is negligible radio frequency (RF) leak-
age from the FT-847 transceiver itself, its antenna sys-
tem should be located as far away from humans and
animals as practicable, so as to avoid the possibility of
shock due to accidental contact with the antenna or
excessive long-term exposure to RF energy. During
mobile operation, do not transmit if someone is stand-
ing adjacent to your antenna, and use the lowest power
possible.
Never stand in front of an antenna (during testing or
operation) when RF power is applied, especially in
the case of 430 MHz directional arrays. The 50 Watt
power output supplied by the FT-847, combined with
the directivity of a beam antenna, can cause immedi-
ate heating of human or animal tissues, and may cause
other undesirable medical effects.
12
E
IELD XPOSURE
E
LECTROMAGNETIC
If this transceiver is used with, or in the vicinity of, a
computer or computer-driven accessories, you may
need to experiment with grounding and/or Radio Fre-
quency Interference (RFI) suppression devices (such
as ferrite cores) to minimize interference to your com-
munications caused by energy from the computer.
Computer-generated RFI is usually a result of inad-
equate shielding of the computer's cabinet or I/O and
peripheral connections. While computer equipment
may "comply" with RF emission standards, this does
not ensure that sensitive amateur radio receivers like
the FT-847 will not experience interference from the
device!
Be certain to use only shielded cables for TNC-to-
Transceiver connections. You may need to install AC
line filters on the power cord(s) of the suspected equip-
ment, and decoupling ferrite toroidal chokes may be
required on interconnecting patch/data cables. As a
last resort, you can try installing additional shielding
within the computer's case, using appropriate conduc-
tive mesh or conductive shielding tape. Especially
check "RF holes" where plastic is used for cabinet front
panels.
For further information, consult amateur radio refer-
ence guides and publications relating to RFI suppres-
sion techniques.
FT-847 O
C
OMPATIBILITY
M
PERATING ANUAL