What is a high VSWR?

High VSWR is indicated by a flashing red LED. This can be caused by multiple factors, including:

• Poor connection or fault with the VHF antenna/cable/connectors
• VHF antenna is unsuitable for AIS frequencies (162MHz)
• VHF antenna is mounted in an unsuitable location (where nearby obstructions or metal structures will interfere with the signal)

Please try checking each of the above to address the problem. If this doesn't resolve the issue please contact support@em-trak.com