WHAT IF POWER LOSS TO AIS SPLITTER ?

[delcrest]

HI, some help or information from those of you using a AIS transponder /vhf spliter, the splitter that I have requires a separate 12vdc power supply, if this 12v supply should blow a fuse or the supply is switched off, does the vhf radio still transmit or would both the radio and AIS transmit basically into a open circuit antennae and destroy themselves
I would like to connect the AIS and the splitter to there own on off switch /fused supply which would enable the AIS to be switched off if required and still have the vhf radio operational
Any comments / advice would be appreciated

[Neptune's Gear]

Good splitters fail to the vhf only.

[sailormed]

Originally Posted by Neptune's Gear

Good splitters fail to the vhf only.

That is what my splitter is doing.

[Jerry Woodward]

I have the Vesper XB8000 and the Vesper SP160 splitter. The splitter is supposed to be switched on the same breaker as the AIS so the splitter is always on when the AIS is on. That is how I wired it. When the power to the AIS/splitter is off, it defaults to the VHF. I have confirmed this....the VHF works fine when the AIS/splitter is off.

[tkeithlu]

Even better, don't combine your systems. Own an AIS with an antenna. Own a VHF with an antenna. The Achilles heal of integrated "glass cockpit" systems is that one failure, even just the monitor screen, leaves you with no source of information. Instead, think "If I loose my AIS, I've still got my radar; if I loose my GPS, I've got another or a paper chart."

[Jerry Woodward]

The problem with using dedicated VHF antennas for both is that the AIS antenna has to be at least 4' from the other VHF antenna (according to Vesper). That makes it hard to locate both at the top of the mast.



I agree redundancy is good, and it is easy to have redundancy with the splitter and shared system. I carry an extra VHF antenna, so if the masthead antenna stops working, I can attach the spare antenna and get VHF. I also carry a handheld VHF. If the splitter fails, it defaults to VHF anyway so I would still have VHF. If I really need AIS in this situation, I can bypass the failed splitter and connect the VHF antenna directly to the AIS and use my handheld VHF.

[S/V Alchemy]

Originally Posted by Jerry Woodward

I have the Vesper XB8000 and the Vesper SP160 splitter. The splitter is supposed to be switched on the same breaker as the AIS so the splitter is always on when the AIS is on. That is how I wired it. When the power to the AIS/splitter is off, it defaults to the VHF. I have confirmed this....the VHF works fine when the AIS/splitter is off.

That's my understanding as well, although I decided to go with a separate antenna for the AIS which is on its own separate breaker.

[Puget Dan]

Originally Posted by Jerry Woodward

I have the Vesper XB8000 and the Vesper SP160 splitter. The splitter is supposed to be switched on the same breaker as the AIS so the splitter is always on when the AIS is on. That is how I wired it. When the power to the AIS/splitter is off, it defaults to the VHF. I have confirmed this....the VHF works fine when the AIS/splitter is off.

Jerry, how do you like theXB8000 vesper? Looking at installing an AIS on our Trimaran.
Dan

[Jerry Woodward]

I really love it. Easy to install, and the WiFi capability really makes it versatile. I initially used my ipad and Inavx to get ais data via WiFi, worked well. Then I got a Zeus 2 MFD and put in a N2K system so now it displays AIS on the Zeus as well. It comes with a GPS antenna and enough cable to locate it wherever you want. The other great thing is the anchor alarm. I can log in with my smart phone and the Vesper Watchmate app and have a great anchor alarm. I really appreciated it one night anchored in the Keys when the current changed 180 degrees during the night. Here is a screen shot showing that the anchor re-set during the night.

So it really is a great value because what you get is not only AIS, but N2K capability, GPS that can be used by the chartplotter or anything else, and a WiFi multiplexer to get data to tablets and phones.

[Puget Dan]

That is just what I needed to know Jerry to pull the trigger. Up here in the Pacific Northwest we have a lot of traffic and adding a good AIS will help. My wife and are taking two months next year and sailing the inside passage to at least.Juneau on or 38’ Trimaran. Thanks again.

[Nicholson58]

Originally Posted by tkeithlu

Even better, don't combine your systems. Own an AIS with an antenna. Own a VHF with an antenna. The Achilles heal of integrated "glass cockpit" systems is that one failure, even just the monitor screen, leaves you with no source of information. Instead, think "If I loose my AIS, I've still got my radar; if I loose my GPS, I've got another or a paper chart."

Good advice. We too have separate antennas for each user. With mizzen, separation is easy. Spare cabling and hand held for emergencies. We see many vessels with mast top antennas and also mounted on the spreaders.

[RaymondR]

Originally Posted by tkeithlu

Even better, don't combine your systems. Own an AIS with an antenna. Own a VHF with an antenna. The Achilles heal of integrated "glass cockpit" systems is that one failure, even just the monitor screen, leaves you with no source of information. Instead, think "If I loose my AIS, I've still got my radar; if I loose my GPS, I've got another or a paper chart."

I installed my first VHF antenna on top of the mast and then got sensible and have been installing them on top of the solar panel frames at the stern ever since. I have not noticed any practical range reduction however have noticed a good deal of practicability improvement. The new boat I have had for the last couple of years has an antenna on top of the mast and had a splitter. It quit working a few months ago so I removed it and spliced the cable, works OK now but if I have problems with it I will remove the entire system and reinstall a new system on the panel mounts.

On the instrumentation issue, Yep, redundancy works.

[delcrest]

Thank you all for your comments, the reason for wanting to use the splitter in my case is there is no where to mount the second antennae on my small catamaran
Basically I have no choice, so I will go with connecting the Simrad NSPL500 splitter and my AIS type B transponder to the same power source which will hopefully allow me to switch the both the AIS and transponder off and just have the radio working

[hellosailor]

delcrest-
Do bear in mind that a true "emergency VHF antenna" is also a fairly small, simple, inexpensive piece of equipment to carry. They're typically sold in a plastic storage tube, maybe 5 meters of a thin decent antenna cord, attached to a simple wire "rod" antenna that is a little more than 1/2 meter long.
To use the emergency antenna, you simply screw that cable into the rear of your VHF, and hoist the emergency antenna (the rod) as high up as you can, wherever you can. And they work perfectly well.
In the US, prices should range somewhere between $25-50 and they are also very easily made, literally from an old radio cable that has been scrapped, and a piece of wire coat hanger, for a whole $10 out of pocket.
Even if you had two masts on your antenna...if that comes down, the emergency antenna in the plastic tube becomes a very handy thing to store in an odd corner. (And it also gives you a "known good" option to compare with, if you suspect the main antenna or splitter is misbehaving.)