Owner's Manual
HighGear Tips
Antenna Assembly
Screw the mast into the base. Loosen the set screw from the
top
of
the
antenna mast. Insert the whip into the mast until it touches the bottom.
Lightly tighten the set screw.
Antenna Mounting
The metal body
of
your vehicle serves as the ground plane for the antenna.
The ideal location for the antenna is on the center
of
the roof
or
trunk lid, as
far away from any structures like luggage racks as possible. Make sure that
all hardware and connections are tightened securely.
Checking The
SWR
(Standing Wave Ratio)
Make sure
your
vehicle is in an open area at least
30
feet from any metal
objects and with the doors, hood and
trunk
closed. Connect an SWR
meter in the
coax
line between the radio and the antenna (unless
your
radio has a built-in SWR meter). Check the SWR on both channel 1 and
channel 40. Readings under
2:1
are considered acceptable, with 1.5:1
or
lower being desirable.
Note An SWR reading
of
over
3:1
on both channel 1 and 40 generally
indicates
an
open
or
shorted
coax
or
a
poor
ground connection.
Re-check these conditions before proceeding. Do
not
use the radio until
the problem has been corrected. An SWR reading between 2.0 and 3.0
generally indicates a problem with
coax
quality or length,
or
an
inadequate ground plane.
Tuning the Antenna:
If the SWR on channel 40 is higher than channel 1: Remove the
whip
from
the mast and trim it
by
1/8
11
to
1/4
11
using a bolt cutter
or
hacksaw.
Re-insert into the mast, tighten the set screw and again read the SWR. If
the SWR reading is still higher than channel 1, repeat until the
two
readings
are approximately equal. If the SWR on channel 1 is higher than channel
40: Loosen the set screw, pull the whip up
1/4
11
, tighten the set screw and
read
the
SWR again. If the SWR is still higher than channel 40, repeat until
the
two
readings are approximately equal. Then firmly tighten the set screw.