Our standard marine VHF and cellular antennas are either halfwave or colinear in design.
The halfwave antenna has one radiating element. It
has a fuller “lobe” than a colinear (see the diagrams on the previous
page). This makes it an ideal antenna for boats working medium ranges
and for installations at the top of the mast. It does not matter if the
boat is rolling around, or is heeled over; the other station is kept in
the lobe, and the owner can communicate with that station.
Halfwave antennas have a gain of 3dBi.
The colinear antennas have two or more radiating elements
which work in unison. Extra elements effectively compress the lobe of the antenna,
which in turn,
increases the range of the antenna. However, because the lobe has been compressed,
other stations may not stay
in the lobe if the boat rolls or is heeled over. For this reason, colinear
antennas are recommended for larger, more stable vessels which need communication
at the maximum range.
Both our halfwave and colinear antennas
are ground plane
independent, meaning that they do not need to be installed on a metal surface
A colinear antenna mounted at the same height as a halfwave antenna will give
greater transmit and receive range, but a halfwave antenna mounted higher than
a colinear antenna will give greater range because it will have a greater “line of sight.” If range is the key factor in your
antenna selection, remember: Height first, gain second.