Aerial Splitter

Tony · 02 July 2007, 07:55

Can anyone recommend a vhf/fm splitter and a place to buy from?

Bern Hanreck · 02 July 2007, 09:05

Try.......RS Components or CPC Farnell or Maplins for starters

all have web sites with search facilities.

Scrumdown · 02 July 2007, 09:31

Quote:

Originally Posted by Tony

Can anyone recommend a vhf/fm splitter and a place to buy from?

Was told in chandlery not long ago in dartmouth not to bother with one as it lowers performance of the VHF and fit two seperate aerials or just a bit of wire inside the console would work with the FM radio.

I know though www.yachtgrot.com used to sell them - send them an e-mail and ask as sometimes they dont have products listed etc

ashbypower · 02 July 2007, 09:34

Personnaly I would not recommend a VHF splitter at all. Its another potential point of failure when most needed, failure could write of the VHF Transmitter, possible adverse effects of Voltage Standing Wave Ratio (VSWR) affect range or worse taking the Tx out. FWIW I would have two independant systems.

Ian M · 02 July 2007, 11:39

I think that you need to be a little more specific about what you are trying to achieve. As others have alluded to here, a simple passive splitter will halve the output power from your antenna. If you are thinking simply in terms of redundancy do what Hugh Jardon has done and have a spare antenna ready rigged and if you have a problem simply swap the connection.
Sorry Brian, but in my opinion you are highly unlikely to get VSWR problems, otherwise when an antenna feed failed the transceiver would go u/s. I think it would be a very poor design that did not incorporate some sort of open circuit protection.

ashbypower · 02 July 2007, 13:54

Whilst I agree with the open circuit senario, there a numerous others that will cause High reflected power

and thus cause Tx problems. I have seen this numerous times on Commercial equipment that has protection above and beyond any thing the leisure market has to offer.

Ian M · 02 July 2007, 18:50

Yep, I can think of numerous scenarios that will cause Tx problems, all that I was trying to point out is that we should not be too paranoid about antennas and cables cause transceivers to self destruct. Of course good practice is always a good idea...................

ashbypower · 02 July 2007, 18:54

................

Tony · 02 July 2007, 19:18

now i am really cofused..

AndrewH · 02 July 2007, 23:25

Quote:

Originally Posted by Tony

now i am really cofused..

Brian and Ian were making very good points, but the tech chat managed to mask it a little.

In summary

1) Don't use a splitter unless you really have to - it'll compromise performance and is somewhere else for your kit to fail
2) Better solution is to have two aerials (one of which is not connected, but ready for use should it be needed)

HTH

Tony · 03 July 2007, 04:59

thanks...

Ian M · 03 July 2007, 11:22

Quote:

Originally Posted by AndrewH

Brian and Ian were making very good points, but the tech chat managed to mask it a little.

In summary

1) Don't use a splitter unless you really have to - it'll compromise performance and is somewhere else for your kit to fail
2) Better solution is to have two aerials (one of which is not connected, but ready for use should it be needed)

HTH

Jon Brooks · 24 February 2008, 16:32

I have a splitter fitted to my rib now.

It is the Easy Split from Echo Pilot.
It is not cheap but works really well.
Whilst on paper it suggest lost, in real terms I have noticed no effect.

I used this one as it goes with the Easy AIS system now fitted.

The splitter allows me to use one antenna for AIS, VHF and FM.

Good value for money really.

Am looking to upgrade the AIS to a transimt version, Echo Pilot do a splitter now to allow tx and rx for both VHF and AIS and also will do FM rx.

MikeCC · 25 February 2008, 15:42

In case anyone wants to know how these work . .

They rely on the fact that the VHF transmit power builds up over milliseconds and that gives enough time to switch the circuit so you don't fry your AIS receiver. During receive, not a problem of course.

The reason a different splitter is needed if you have an AIS transponder is that they produce a digital signal where full power is almost instantaneous. A switch time in microseconds is therefore needed to avoid the AIS unit cooking the radio.

9D280 · 26 February 2008, 10:53

Just an observation, but

Splitter - £100+ish
Second Antenna (which will probably come with cable, plugs etc) - £50 ish.

Jon Brooks · 26 February 2008, 11:13

Quote:

Originally Posted by 9D280

Just an observation, but

Splitter - £100+ish
Second Antenna (which will probably come with cable, plugs etc) - £50 ish.

Very true but it is not always that easy to mount a second or in my case third antenna.
So it can save time and effort in many case, is that worth £50ish? only you can answer that, but is sure was for me.

MikeCC · 26 February 2008, 14:33

Quote:

Originally Posted by 9D280

Just an observation, but

Splitter - £100+ish
Second Antenna (which will probably come with cable, plugs etc) - £50 ish.

As Jon says - depends if it's worth doing for your particular installation. eg a yacht with a masthead antenna where someone is being paid to install the cable all the way down the mast and conceal it nicely in the cabin is going to be a lot more expensive than a DIY RIB installation from A-Frame to console.

There are pros and cons - personally if there's room I'd always go for a dual antenna so you have a backup. Use a PL-259 to BNC adapter on the AIS antenna, then if you need the antenna for radio you just need to unscrew the adapter.

Also make sure that there's enough spare in the cable to reach the radio as well (yes, it did happen to a customer!)

ChrisB123 · 01 March 2008, 16:54

Hi guys,

Have just read this thread in amasements.

I have just bought an aerial splitter (Pacific Aerials) so i can run the FM radio on my Aquatic AV marine player from the same aerial that supplies the Icom.

Is this going to work?

MikeCC · 10 March 2008, 15:48

Quote:

Originally Posted by ChrisB123

Hi guys,

Have just read this thread in amasements.

I have just bought an aerial splitter (Pacific Aerials) so i can run the FM radio on my Aquatic AV marine player from the same aerial that supplies the Icom.

Is this going to work?

Sorry, missed this one. Yes, will work, no problem. OK for FM radio but probably not for AIS receiver - that's the difference.