Antenna installation
Antenna selection
This radio is designed to operate into a 52 ohm
CITIZENS BAND RADIO antenna. Best results
will be obtained from your transceiver if you use
a good antenna, properly installed. (Refer to
the antenna installation instructions included with
your antenna.)
A vertically polarized quarter-wavelength whip
antenna provides the most reliable operation and
greater range. The shorter loaded-type whip
antennas are more attractive, compact and
adequate for applications where the maximum
possible distance is not required. Also, the load-
ed whip antennas do not present the problems of
height imposed by the full quarter-wavelength
whip.
Mobile whip antennas utilize the metal body of
the vehicle as a ground plane. When mounted
on a corner of the vehicle, they are slightly direc-
tional, in the direction of the body of the vehicle.
For all practical purposes, however, the radiation
pattern is non-directional. A slight directional
characteristic will be observed only at extreme
distances. A standard antenna connector (Type
SO-239) is provided on the transceiver for easy
connection to a standard PL-259 cable termina-
tion.
There are many types of approved aerials and
mounts for the motor vehicle, the most common
of which is the 1.5metre fibreglass helical whip
(A51C). For the best performance, this type of
aerial is fitted to an (ABS) vehicle mount situated
in the centre of the vehicle roof. The connection
of a (CBL 12) 4 metre lead from the mount to the
.
TX 560 completes the ideal aerial system. The
aerial is then tuned to maximum performance
with the aid of an S.W.R. meter (310). Either
your C.B. dealer will do this for you or show you
how. If it is not desirable to drill a hole in your
vehicle roof, other mounts are available i.e. the
(ABGM) gutter mount or the (AB12) roof rack
mount. Alternative length helical whip aerials
are also available (see "Optional accessories").
For vehicles with non metallic i.e. trucks with
fibreglass cabin tops the aerial may be mounted
on the cabin roof or on the rear vision mirror
bracket.
Because of the absence of a metal ground plane,
best performance will be obtained by connecting
the aerial to a matcher unit (Matcher 140) which
must be adjusted with an S.W.R. meter, or an
ATU27 which has its own tuning indicator. The
output of either units then connects to the
antenna socket on the transceiver.
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