Active splitter for VHF and AIS. Disappointed at the moment.

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FairweatherDave

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Following my previous thread I finally got to test out my new AIS receiver with my new Metz VHF antenna mounted on the rail.
Really impressed with the range. Saw the mass of clutter between Chichester and Cowes . However when routing the cable via the Glomex Active splitter range was POOR, eg 1 or 2 miles. Why could that be? I know splitters are like marmite, but often the arguments tend to be about building in redundancy, the advantages of having 2 antennae, or having a dedicated AIS antenna because it is at the edge of the frequency for VHF. But I was getting good range going direct to the receiver. So is there anything I can do apart from checking connections (which I am sure are fine). Is this the real problem with active splitters? Or should I contact Glomex? Thanks for any pointers.
 
My only experience is with a masthead aerial. The splitter is 'Easy split', apparently produced by someone called 'Weather Dock'. I regularly get 25-40 miles, which is about as much as I would expect without a splitter, so it sound as if there's something wrong somewhere.
 
Sounds like the splitter is not working. On my Vesper Marine AIS I get about 3 miles horizon if the thing is not plugged into the splitter, don't ask how I know.
 
FairweatherDave said:
Following my previous thread I finally got to test out my new AIS receiver with my new Metz VHF antenna mounted on the rail.
Click to expand...

Do you need a splitter if you have an AIS aerial on the rail?

Maybe get someone with a meter to test the input and output of your splitter and how much signal loss there is?
 
lpdsn said:
Do you need a splitter if you have an AIS aerial on the rail?

Maybe get someone with a meter to test the input and output of your splitter and how much signal loss there is?
Click to expand...

Good idea ..........but it's finding that elusive " someone with a meter" :) (and who understands what it says :)).( I am making the assumption the testing would need to be done at the boat rather than a workshop)

But my antenna is on the rail for now as my masthead aerial has a fault somewhere (and I have redone the PL259 plug more than once so suspect the cable).
 
FairweatherDave said:
Good idea ..........but it's finding that elusive " someone with a meter" :) (and who understands what it says :)).( I am making the assumption the testing would need to be done at the boat rather than a workshop)

But my antenna is on the rail for now as my masthead aerial has a fault somewhere (and I have redone the PL259 plug more than once so suspect the cable).
Click to expand...

I think you would need to test the full system rather than just the splitter. The issue could be a plug, for example, rather than the splitetr itself. Impedence mismatch would cause part of the signal to be reflected.

Yes, awkward to find someone with a meter who knows how to use it. At least in the Solent there might be another forumite with one nearby.
 
RobbieW said:
Dumbass question perhaps, but the splitter is powered up ? and what happens if you disconnect the VHF and put that cable into the AIS ?
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It is quite feasible power is not getting to the splitter. That is my first check next time I go to the boat. Annoyingly as far as I can see there is no little led glowing light to show you it has power. However once I had established I did have excellent AIS reception by-passing the splitter (and disconnecting the VHF) my priority was to turn round and get back into Chichester over the bar near low water with a SSE force 4 making it a wee bit lumpy (neither I nor my wife had expected that and relations were a little tense :).
(For the sake of accuracy it was nowhere near F4 when we actually crossed the bar returning but it had felt like it heading out)
 
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Presumably if you're adding the splitter into the mix then you'll also be adding an extra cable... Active splitters should not add any measurable loss. I'm wondering if you have a faulty patch cable. Are all your pl295 plugs soldered and screwed in firmly?
 
Martin_J said:
Presumably if you're adding the splitter into the mix then you'll also be adding an extra cable... Active splitters should not add any measurable loss. I'm wondering if you have a faulty patch cable. Are all your pl295 plugs soldered and screwed in firmly?
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Not sure what you mean by a "faulty patch cable" ?
The splitter comes with 3 plugs leaving the unit, they are factory assembled (one PL259, one BMC and one FM radio).
The only PL259 I have fitted is on the end of the antennae cable and that is soldered and screwed up nicely ( and functions well going into the Quark AIS unit with a converter to BNC).

For clarity the 3 plugs are on the end of 3 cables leaving the splitter.
 
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knuterikt said:
Have you tried to connect the AIS directly to the masthead antenna?
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I believe that the cable to the masthead is faulty having already replaced the PL259 and the radio. I went through a reasonable process of elimination before deciding to put a new antenna on the rail with new cable. However if being pedantic, I probably did not test the AIS directly to the masthead antenna in open water, only in the confines of Chichester harbour, (a pretty large harbour) where I got incredibly poor results. But equally the masthead antenna was failing as a VHF radio antenna so I knew I had a problem.
 
FairweatherDave said:
Not sure what you mean by a "faulty patch cable" ?
The splitter comes with 3 plugs leaving the unit, they are factory assembled (one PL259, one BMC and one FM radio).
The only PL259 I have fitted is on the end of the antennae cable and that is soldered and screwed up nicely ( and functions well going into the Quark AIS unit with a converter to BNC).

For clarity the 3 plugs are on the end of 3 cables leaving the splitter.
Click to expand...

I'd assumed you'd made up a BNC cable for AIS direct to antenna cable... I'd assumed this because usually your antenna cable is pl259 yet the AIS units are sometimes BNC.
 
Martin_J said:
I'd assumed you'd made up a BNC cable for AIS direct to antenna cable... I'd assumed this because usually your antenna cable is pl259 yet the AIS units are sometimes BNC.
Click to expand...

:) Yes. For direct antenna to AIS connection I used a SO239 to BNC converter to be able to continue using the PL259 on the cable from the antenna.
 
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