I have an Apelco VHF mounted in the nav station with a remote speaker in the cockpit. A Raymarine handheld is kept near the helm. Of course the handheld has nowhere near the range of the fixed VHF below. Instead of replacing the [perfectly good] Apleco VHF, I would like to install a second fixed VHF at the helm connected in such a way to share the mast top antenna. Is there an adapter or junction/splitter type device which will allow both VHFs to be on at the same time (not transmitting, of course) and share a common antenna without manual switching or other intervention?
2 VHFs sharing 1 VHF antenna
- Thread starter Kailani
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West Marine
I believe that either manual or automatic splitters are available to do what you wish. Try West Marine link below. Dan Jonas (S/V Feije II)
I believe that either manual or automatic splitters are available to do what you wish. Try West Marine link below. Dan Jonas (S/V Feije II)
Command mike
I am not sure if Apelco offers a command mike option. Our raymarine and I have seen the RAM mike for horizon. These are mikes that have full radio control functionality and generaly plug into the radio. We add the command mike to our raymarine and it only cost $89 from West Marine. This may be a lower cost option while providing the range required. The second option is to run two radios with two seperate antennas. We have seen many boats in the caribe with the second radio mounted in the cockpit with a second antenna mounted on the stern rail. This provides very good range (not quite as good as the top of the mast), but also provides radio redundency. If you were to lose the mast top antenna you have a second radio for immediate operations.
I am not sure if Apelco offers a command mike option. Our raymarine and I have seen the RAM mike for horizon. These are mikes that have full radio control functionality and generaly plug into the radio. We add the command mike to our raymarine and it only cost $89 from West Marine. This may be a lower cost option while providing the range required. The second option is to run two radios with two seperate antennas. We have seen many boats in the caribe with the second radio mounted in the cockpit with a second antenna mounted on the stern rail. This provides very good range (not quite as good as the top of the mast), but also provides radio redundency. If you were to lose the mast top antenna you have a second radio for immediate operations.
food for thought
I have a second VHF radio at the helm, connected to a 6db antenna mounted on a ss tube on the stern rail. Also have a radio at the nav station, so I have a backup radio and antenna. Served me well during a recent trip to the keys when the nav station radio did not work reliably (being replaced) and the helm radio served as a backup.
I have a second VHF radio at the helm, connected to a 6db antenna mounted on a ss tube on the stern rail. Also have a radio at the nav station, so I have a backup radio and antenna. Served me well during a recent trip to the keys when the nav station radio did not work reliably (being replaced) and the helm radio served as a backup.
RF SENSING SWITCH
There are RF sensing switches which allow two independent xcvrs to use the same antenna, however, I doubt you would find it practical given your application. Sounds like you want to use one antenna and auto-switch between two xcvrs. All the switches I've seen require uninterruptable power, typically 110VAC, and can generate a sig amount of heat. The argument can be made that they could be used through an inverter but the power drain will be significant. Add to that the inherent signal loss of switches and the likleihood of eventual failure or malfunction at the wrong time and you are left with a bad switch which just cooked the other xcvr. Someone here may have a better source or idea but it sounds to me like the best idea is to use two xcvrs and two antennas. Don
There are RF sensing switches which allow two independent xcvrs to use the same antenna, however, I doubt you would find it practical given your application. Sounds like you want to use one antenna and auto-switch between two xcvrs. All the switches I've seen require uninterruptable power, typically 110VAC, and can generate a sig amount of heat. The argument can be made that they could be used through an inverter but the power drain will be significant. Add to that the inherent signal loss of switches and the likleihood of eventual failure or malfunction at the wrong time and you are left with a bad switch which just cooked the other xcvr. Someone here may have a better source or idea but it sounds to me like the best idea is to use two xcvrs and two antennas. Don
We used a two-way antenna selector
from West Marine to switch between a VHF at the nav station below and one in the cockpit. It worked fine for us.
from West Marine to switch between a VHF at the nav station below and one in the cockpit. It worked fine for us.
Just Remember
you can always use an antenna splitter to feed two receivers, but you cannot tie two transmitters to the same antenna with a splitter. For doing that you must use an rf switch. Keep in mind that you will be transmitting from one transmitter into the second receiver unless the switch terminates the second receiver input. Even with two antennas, you could burn out the other receiver if the antennas are too close.
you can always use an antenna splitter to feed two receivers, but you cannot tie two transmitters to the same antenna with a splitter. For doing that you must use an rf switch. Keep in mind that you will be transmitting from one transmitter into the second receiver unless the switch terminates the second receiver input. Even with two antennas, you could burn out the other receiver if the antennas are too close.
additional food for thought
I would like to add on to what the previous boater indicated regarding a second 3 or 6 Db antenna at a stern pole or even mounted on the aft pulpit. This is what we opted to do to provide full redundancy. seperate antenna, radio and breaker so as to have a greater peace of mind. The second radio and antenna provide for a very stong signal. Far superior to a handheld that we now keep in the ditch bag.
I would like to add on to what the previous boater indicated regarding a second 3 or 6 Db antenna at a stern pole or even mounted on the aft pulpit. This is what we opted to do to provide full redundancy. seperate antenna, radio and breaker so as to have a greater peace of mind. The second radio and antenna provide for a very stong signal. Far superior to a handheld that we now keep in the ditch bag.
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