[DG] [DG] AIS 700 - AIS Antenna problem

[Derek - Raymarine - Moderator]

Hi nachothecat

Thankyou for your enquiry.

The key diagnostics to check in PRO AIS2 is the VSWR reading . . ideally it should be between 1.0 :1 and 2.0 : 1, VSWR is a ratio of how efficient the antenna (and cable) is, the higher the ratio the poorer the performance.

check out this FAQ found here for more information, ( it refers to AIS 650, but the antenna issues will be the same)

So if the VSWR is high, then either the antenna is at fault or the cable/ connections to the antenna. Please also bear in mind that some antennae are not suitable for AIS transmissions, most antenna are specified for a range of frequency and AIS operates circa 162MHz, this needs to be in the middle of the range for the antenna selected.

regards
Derek