Vhf splitter for ais transceiver

[DinghySailor]

According to the calculator, that's a difference on my boat (from 8' to 55' off water) of about 2x the range. Good stuff as usual John, thx.

 

[dlochner]

Yes, I'm leaning toward a second antenna, but it would need to be either on a new antenna pole mounted on transom or off the bimini assembly (no arch), which is fairly stout. I'm concerned about transceiver / receiver range with a lower antenna and also signal disruption from rod backstay, etc.

Don't overthink this. Any interference will be minimal from rigging will be minimal. The big loss will be lack of height. The only time you would need a second antenna is if the mast came down, an unlikely occurrence. In that case a satellite communication device would be more valuable than an VHF 10 feet off the water.

With that said we do carry an emergency antenna.

Shakespeare Stowaway Portable VHF Antenna - 5911

The Shakespeare 5911 Stowaway™ Portable VHF Antenna is a base loaded 1/4-wave emergency VHF flex antenna to use if main antenna becomes disabled. Features: Easily mountable in an emergency Packed in 12" weather-resistant plastic tube Fl

defender.com

 

[Mifeo]

What are your thoughts on, AMEC CAMINO-108S Class B AIS Transponder with integrated splitter

I would have liked to have gone with the Camino with integrated splitter, however at the time I installed the AIS it was part of an electronics update for the boat. I didn't research the AIS much.

What I've learned since is that the mast mounted VHF (16m high) is way superior to the stern rail 2nd antenna (4m). The distance for send and receive is MUCH greater for the mast antenna (of course). Since then I changed the system to add a Camino 162 antenna splitter and route everything through the mast antenna.

I haven't noticed any issues with the VHF since adding the splitter. My AIS performance is great, I can see other boats at a much greater distance.

 

[BarryL]

Hi,

My boat came with a Vesper XB8000 AIS transponder, Standard Horizon VHF radio, single VHF antenna at the masthead and SP160 VHF splitter. Everything works well - other vessels can 'see' my AIS information, I receive AIS info. etc.

When I receive voice VHF transmissions, I feel like the sound cuts out briefly every 5 seconds or so. Am I hearing the results of the AIS information being received, which temporarily blocks the voice VHF information?

I usually use a hand held VHF, so the cut out on the ship VHF is more of an annoyance than anything else. I just am curious if what I hear is normal or if there is a problem.

Thanks
Barry

 

[dlochner]

Hi,

My boat came with a Vesper XB8000 AIS transponder, Standard Horizon VHF radio, single VHF antenna at the masthead and SP160 VHF splitter. Everything works well - other vessels can 'see' my AIS information, I receive AIS info. etc.

When I receive voice VHF transmissions, I feel like the sound cuts out briefly every 5 seconds or so. Am I hearing the results of the AIS information being received, which temporarily blocks the voice VHF information?

I usually use a hand held VHF, so the cut out on the ship VHF is more of an annoyance than anything else. I just am curious if what I hear is normal or if there is a problem.

Thanks
Barry

I don't think so, AIS transmission are not that frequent. Do you have scanning on for different channels? That could cause the same symptoms as the receiver quickly scans those channels.

 

[jssailem]

As Dave shared, the AIS for class B transceivers is 30 seconds. I posted a white paper with details about AIS this last week.

The Vesper splitter is designed to favor VHF over AIS so if you are transmitting VHF you get the antenna. The AIS skips a cycle and waits 30 seconds for the next transmit window. AIS is a 2watt short data transmission.