Interference From Radar, Gps, L-Band And Other Transmitters - Furuno FV-110GX Operator's Manual

2.2.7

Interference from radar, GPS, L-band and other transmitters

Note
Mount the ADU as far away as possible from the ship's radar and high power radio
transmitters, because they may compromise the ADU performance. RF emission from
radars might actually damage the ADU.
The FV-110GX ADU itself may also interfere with other radio systems.
Radar
It is difficult to give exact guidelines for the minimum distance between a radar and the
ADU because radar power, radiation pattern, frequency and pulse length/shape vary from
radar to radar. Further, the ADU is typically placed in the near field of the radar ADU and
reflections from masts, decks and other items near the radar vary from ship to ship.
However, it is possible to give a few guidelines. Since a radar radiates a fan beam with a
horizontal beam width of a few degrees and a vertical beam width of up to +/- 15°, you
can avoid the worst interference by mounting the ADU at a different level – meaning that
the ADU is installed minimum 15° above or below the radar antenna. Due to near field
effects the benefit of this vertical separation could be reduced at short distances (below
approximately 10 m) between radar antenna and the FV-110GX ADU. Therefore it is
recommended to ensure as much vertical separation as possible when the FV-110GX
ADU has to be placed close to a radar antenna.
Do not place the ADU close to interfering signal sources or receivers. For
allowed distances to other transmitters see Figure 2-13: Recommended
distance to transmitters (m) for frequencies below 1000 MHz on page 2-
15. We recommend testing the total system by operating all equipment
simultaneously and verifying that there is no interference.
Radar
Figure 2-12: Interference with the vessel's radar
Min. 15°
Min. 15°
Site preparation
2-13