Location of the mandatory AIS VHF-antenna should be carefully considered
To minimise interference effects, the following guidelines apply:
• The AIS VHF antenna should have omnidirectional vertical polarisation providing 3 to 5 dB gain.
• The AIS VHF antenna should be placed in an elevated position that is as free as possible with a minimum of 2 metres in horizontal direction from constructions made of conductive materials. The antenna should not be installed close to any large vertical obstruction. The objective for the AIS VHF antenna is to see the horizon freely through 360 degrees.
• The AIS VHF antenna should be installed safely away from interfering highpower energy sources like radar and other transmitting radio antennas, preferably at least 3 meters away from and out of the transmitting beam.
• There should not be more than one antenna on the same level. The AIS VHF antenna should be mounted directly above or below the ship’s primary VHF radiotelephone antenna, with no horizontal separation and with a minimum of 2 metres vertical separation. If it is located on the same level as other antennas, the distance apart should be at least 10 metres.
Det kan bli svÃ¥rt att uppfylla alla krav samtidigt …