Correct installation of the antenna is very important, the ANT4a must be mounted 'in the clear' and well away from metal objects or rigging wires and away from other antennas by at least 50cm. Any compromise in the positioning of the antenna could result in reduced reception performance. There is normally very little advantage in placing a NAVTEX antenna at mast head, however raising the antenna up to about 6m above sea level can sometimes improve reception if problems are experienced. This could certainly be the case if the vessel suffers from high levels of electrical noise. Battery chargers, inverters and other electrical systems can cause such noise problems and effect the quality of long range NAVTEX reception. Elevating the antenna can move it out of the noise zone that can sometimes be associated with electrical equipment. Lifting it above the main effect of such electrical noise.