Antenna Requirements
And Attachment
Nothing Comes Close to a Cobra
®
21
20 English
Antenna Requirements
And Attachment
Installation And Start-Up
Installation And Start-Up
Antenna Requirements And Attachment
•
Antenna Requirements
Your Cobra Marine VHF radio requires an external marine antenna
to send signals into the air and to receive them. The radio is arranged
to use any of the popular marine VHF antennas, but it is up to you to
choose which antenna to use.
Since it represents the link between your radio and the outside world,
Cobra
®
suggests you purchase the best quality antenna, coaxial cable,
and connectors you can. This is best accomplished with the advice
and guidance of a knowledgeable dealer who can assess the variables
involved with your particular boat and preferences.
WARNING
Compliance with FCC requirements for Radio Frequency Exposure is
the responsibility of both the antenna installer and the radio operator.
Safe Maximum Permissible Exposure (MPE) Radius
To avoid health hazards from excessive exposure to RF energy, FCC OET Bulletin
65 establishes an MPE radius of 10’ (3 m) for the maximum power
of your radio with an antenna having a maximum power gain of 9 dBi.
This means that all persons must be at least 10’ (3 m) away from the
antenna when the radio is transmitting.
Installation Requirements
A) An omnidirectional antenna with a gain not greater than 9 dBi must
be mounted at least 16.4’ (5 m) above the highest deck where people
may be during radio transmissions, measured vertically from the lowest point
of the antenna. This provides the minimum separation distance
to comply with RF exposure requirements and is based on the MPE
radius of 10’ (3 m) plus the 6.6’ (2 m) height of an adult.
B) For vessels without structure to mount the antenna as described in A,
it must be mounted as follows AND all persons must be outside the
10’ (3 m) MPE radius during radio transmissions. The antenna must
be mounted so that its lowest point is at least 3.3’ (1 m) vertically above
the heads of all persons during radio transmissions.
Radio Operator Requirements
Do not transmit when anyone is within the MPE radius of the antenna unless
that person or persons are shielded from the antenna by a grounded metallic
barrier. This is especially important on vessels with antennas mounted as
described in B where no one may be within 9’ (2.8 m) horizontally from the base
of the antenna during transmissions.
FAILURE TO OBSERVE THE ABOVE LIMITS MAY EXPOSE THOSE WITHIN
THE MPE RADIUS TO RF ENERGY ABSORPTION IN EXCESS OF THE FCC
MAXIMUM PERMISSIBLE EXPOSURE. IT IS THE RADIO OPERATOR’S
RESPONSIBILITY TO INSURE THAT MPE LIMITS ARE HEEDED AND THAT
NO ONE IS WITHIN THE MPE RADIUS DURING TRANSMISSIONS.
Antenna Lead Attachment
Once the antenna is installed, the
Coaxial Cable Lead
can
be attached to the socket at the back of the transceiver.
CAUTION
Attempting to transmit without an antenna attached will
damage your Cobra Marine VHF radio.
Coaxial Cable Socket
