VHF Antenna

Aug 11, 2011
1,015
O'day 30 313 Georgetown MD
If you have two fixed VHF radios on your vessel, do you need to have two antennas or in the case of a sailboat, can the masthead antenna cable be split to connect to both radios? I have seen a lot of vessels with two VHF's on line, I understand the purpose of having two, however the connectivity to antennas interests me. Anyone?
 
Sep 25, 2008
1,096
CS 30 Toronto
One antenna each, for sailboat I would put one on the stern rail. In case the masthead got blown off or lightning strike, you have a backup.
 
Sep 25, 2008
7,606
Alden 50 Sarasota, Florida
All splitters have an inherent loss. Also, they can fail and you will not know it until too late.
 
Aug 11, 2011
1,015
O'day 30 313 Georgetown MD
For highest positioning, would two on top of the mast be possible. I would mount one on each side. Would they cause any interference?
 

Rick D

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Jun 14, 2008
7,199
Hunter Legend 40.5 Shoreline Marina Long Beach CA
You don't need two on the masthead. Just put the primary one on it and use a stern rail mount for the second. Remember that power boats don't have masts.
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
It is not a good idea to attach two high voltage producing devices to the same antenna unless you want to fry the unit that is not transmitting with the output of the one that has the PTT key held down. The high voltage from the unit that is transmitting goes to the antenna and to the unit that is not transmitting. The receive side of a trancever is not designed to handle a lot of power. The power coming in from the antenna is measure in milli (1/1000) watts. Your 1 watt output that also goes to the receiveing unit is thousands of times what is was designed to handle.
 
Sep 25, 2008
7,606
Alden 50 Sarasota, Florida
For highest positioning, would two on top of the mast be possible. I would mount one on each side. Would they cause any interference?
There would be some parasitic coupling. Difficult to predict the result which could alter radiation pattern or detune both causing a mismatch. Best to isolate antennas of similar resonant frequency.
 
Aug 11, 2011
1,015
O'day 30 313 Georgetown MD
Thanks for all the input. Rail antenna it is. The new radio will be the the Standard Horizon GX2200 with AIS, GPS and DSC.