VSWR Definition for Vesper Equipment

VSWR stands for Voltage Standing Wave Ratio and is a measure of how well matched a transmission line (e.g. an antenna cable connected to the VHF output of WatchMate) is to its termination impedance (e.g. antenna). VSWR can be thought of as a comparative measure of how much power, generated from the WatchMate or XB Transponder, is delivered to the antenna and how much of it is reflected back and lost in the poorly matched transmission line. This is important as it will effect transmission performance. A high VSWR will reduce effective transmission range and can also lead to other problems. If WatchMate is reporting a problem with the antenna connection or high VSWR, look at the Cortex Onboard & WatchMate Apps Display "Trying To Connect" After Update to iOS 14.

To learn more about VSWR there is a great explanation given at Microwaves101.com. For those not technically inclined, just be concerned with ensuring that the cables and connections from WatchMate to the antenna are sound and the antenna is well matched at AIS frequencies (162MHz) and is not mounted too close to any large metal objects.