VHF/AIS/FM aerial splitter

[Cspirit]

I'm considering fitting one of these but I know that some of you feel that it's preferable to have separate aerials. I assume that this is because VHF transmissions might damage the AIS and FM receivers. I've had a splitter for VHF & FM on previous boat with no problems but I suppose that I've never transmitted with the VHF when the FM radio has been on. However, I expect that a VHF transmission when AIS is on is quite likely. Any thoughts?

 

[shmoo]

I have separate aerials. AIS one is a ordinary VHF whip but on the pushpit. Range is about 10 - 15 miles, which is plenty for AIS. With same type of plug on inside as the main aerial end it serves as an emergency aerial for VHF with easy change over.

I would not trust a splitter whatever anyone says about them not causing damage.

 

[Guest]

Keep it simple. One for one.

Ignoring all those things that go bleep AFTER you have sunk/drowned, the VHF is your only early warning of imminent danger device aboard. Give it the respect it deserves and do not compromise it with additional connectors etc.

 

[jimi]

[ QUOTE ]
I have separate aerials. AIS one is a ordinary VHF whip but on the pushpit. Range is about 10 - 15 miles, which is plenty for AIS. With same type of plug on inside as the main aerial end it serves as an emergency aerial for VHF with easy change over.

I would not trust a splitter whatever anyone says about them not causing damage.

[/ QUOTE ]

Same here.

 

[AliM]

Also in favour of separate aerial. If you are dismasted and lose your primary aerial, you'd probably want to use your VHF - it's a ready-mounted spare (assuming it's not on the mast too, of course).

 

[rogerthebodger]

Don't go with a splitter go with 2 seperate aerials as I will but I will also be fitting a coax changeover switch to allow the AIS to be connected to the mast head aerial and the VHF to the pushpit aerial until I need the range on the VHF in which case I will switch the VHF to the mast head.

details here

 

[RestlessL]

VHF whip aerial on the pushpit connected to a VHF/FM splitter feeding AIS and FM radio. Cable is long enough to be disconnected from the splitter and into the VHF radio should I loose the mast-head aerial.

The only problem is the danger of transmitting 25W from the pushpit aerial whist I am next to it.

John

 

[steve6367]

I use Easy AIS and Easy AIS AIS/VHF/FM Antenna Splitter shown here:-

http://www.jgtech.com/shop10.htm

I prefer not to have the clutter of another aerial. My backup plan is a pair of handheld's for emergency use.

Steve

 

[Salty John]

That's an active splitter giving the best protection against transmitting into your AIS. Some are tempted by a passive splitter because it's cheaper than an antenna and mount, but definitely not recommended.

 

[Cspirit]

Thanks everyone, for your rapid responses. The consensus is for separate aerials, so I think I'll go that way, using Restless' excellent idea of a pushpit mounted AIS/FM aerial.

 

[Talbot]

[ QUOTE ]
[ QUOTE ]
I have separate aerials. AIS one is a ordinary VHF whip but on the pushpit. Range is about 10 - 15 miles, which is plenty for AIS. With same type of plug on inside as the main aerial end it serves as an emergency aerial for VHF with easy change over.

I would not trust a splitter whatever anyone says about them not causing damage.

[/ QUOTE ]

Same here.

[/ QUOTE ]
Me Three

/forums/images/graemlins/smirk.gif

 

[Oldhand]

[ QUOTE ]
I use Easy AIS and Easy AIS AIS/VHF/FM Antenna Splitter shown here:-

http://www.jgtech.com/shop10.htm

I prefer not to have the clutter of another aerial. My backup plan is a pair of handheld's for emergency use.

Steve

[/ QUOTE ]

I also use an Easy AIS splitter that works very well. AIS range typically 31nm (16m antenna base height), improved AM & FM radio reception over any alternative I have used in the past, AIS antenna output gives weatherfax reception often little different from backstay long wire antenna and the VHF works as well with the splitter as it did without it.

Should there be any problem, the Splitter is mounted with wasy access so I can easily reconnect the masthead antenna directly to the VHF transciever, should the splitter fail. It is an "active" splitter that disconnects the AIS and FM radio outputs when the VHF transmits and sensibly this should be the failure mode so there isn't any risk of harming equipment.

 

[jb2006]

Yer all luddites - bet you wouldn't trust them new fangled electrical typewriter things either /forums/images/graemlins/laugh.gif

A good splitter hardwires the VHF to the aerial and simply disconnects the other receivers when the VHF transmits. The benefit of having the spare antenna on the pushpit should you lose the masthead one is real though - there are not many 25 watt handhelds! We carry an emergency antenna but a pushpit antenna is much cheaper than a splitter and an emergency antenna.

What about multiplexers though - is there an issue with the 38K baud rate for the AIS and the 8K rate for the DSC position signal - or are Raymarine exaggerating the benefit of their seemingly expensive AIS/splitter/multiplexer ?

 

[shmoo]

[ QUOTE ]

A good splitter hardwires the VHF to the aerial and simply disconnects the other receivers when the VHF transmits.


[/ QUOTE ]

You hope.

"The most reliable component of any system is the one which is not present" No splitter, hence no chance of splitter failing. Luddite? If you like.