VHF splitter problems

[davidivorwynphillips]

Recently purchased a glomex VHF splitter (RA201 - three way - VHF-AIS-AM). It seems to be generating a lot of interference that the squelch control on my VHF receiver won't suppress. Interestingly it seems to be worse on certain channels - including 16. Anyone had similar problems or found a solution?

 

[RichardS]

You are using it with an AIS receiver and not a transceiver, I assume?

Disconnect the AM/FM and try it with just VHF and AIS receiver.

Richard

 

[PhilipH]

Yup we started with a splitter for VHF and AIS. Hopeless - gave up and had dedicated, separate antennae.

 

[Sandy]

Have you got any chokes you can add? I have a choke on my VHF and FM radio.

 

[johnalison]

I can't tell you the tech details, but mine has worked perfectly for several years with VHF & AIS receive + class B, so it is possible with the right equipment.

 

[david_bagshaw]

I can't tell you the tech details, but mine has worked perfectly for several years with VHF & AIS receive + class B, so it is possible with the right equipment.

Have had a similar set up, for 6 years. Digital Yacht make a good splitter. Quality is essential for splitters, along with the quality of the electrical connections

 

[davidivorwynphillips]

Just an AIS receiver. Problem persists with only the VHF connected.

 

[davidivorwynphillips]

Have you got any chokes you can add? I have a choke on my VHF and FM radio.

Do you know what sort of choke?

 

[RichardS]

Just an AIS receiver. Problem persists with only the VHF connected.

I wonder if the splitter is faulty? Speak to Glomex and they may well offer to swap it.

Richard

 

[Salty John]

It could be fault in the connector feeding the splitter, so if possible, connect antenna directly to the radio and if the fault persists, it isn't the splitter. Check the connector for a short.
If the problem goes away when you remove the splitter, the fault lies with the splitter.

 

[davidivorwynphillips]

It could be fault in the connector feeding the splitter, so if possible, connect antenna directly to the radio and if the fault persists, it isn't the splitter. Check the connector for a short.
If the problem goes away when you remove the splitter, the fault lies with the splitter.

Yes the problem goes away when you leave out the splitter

 

[DAVAIS]

Check how much gain the splitter have, you should fine the answer on the manual. More than 10db will be good otherwise you maybe have bad experience.

 

[SV-Apres]

I have this same issue

Have you got any chokes you can add? I have a choke on my VHF and FM radio.

where did you add the chokes? onto the power lines?

 

[DAVAIS]

I have this same issue



where did you add the chokes? onto the power lines?

Correct, but don't expect you will see a big difference. A proper active splitter with high gain/less insert loss should helps more.

 

[Jamie Dundee]

Personally wouldn’t have a splitter on the boat. The more connections between transmitter and antenna the more potential for frying the transmitter. I added a rubber ducky type antenna for radio and have separate antennae for AIS and VHF.

 

[SV-Apres]

Correct, but don't expect you will see a big difference. A proper active splitter with high gain/less insert loss should helps more.

I have the Glomex splitter powered by the "Stereo" circuit which has my Stereo and a USB Hub, which powers a Raspberry Pi and WIFI Router and then the VHF is connected to the "VHF" Circuit.

With the with the "VHF" and the "Stereo" Circuits on the VHF has constant static that you cannot squelch out. if you turn off the "Stereo" Circuit (Glomex, USB Hub, Raspberry Pi, Stereo - all off) the VHF goes quiet. I plan to do some elimination experiments to see if the noise if coming from just the Glomex or from the other sources, but i do have a couple of Ferrite cores from another project I could try as well.

 

[jbweston]

Have had a similar set up, for 6 years. Digital Yacht make a good splitter. Quality is essential for splitters, along with the quality of the electrical connections

Me too for about 4 years. Works fine.

 

[PaulRainbow]

Never was a fan of splitters, always preferred a separate antenna. However, over the past year or so i have fitted several splitters as part of AIS installs, using the Emtrak AIS sailor pack, which includes a splitter. Never had an issue with one. There is much truth in post #6 "Quality is essential for splitters "

 

[ears media]

The trouble with these devices is that they're not really just a splitter. Splitters rarely cause any issues, being a passive device (with sometimes a bit of receive gain to bring the performance back to unit gain). The AIS antenna sharing devices have a very fast switch internally that prevents the AIS data burst getting to your comms radio receiver, and another to prevent your comms RF going back down the AIS cable. Just a bit of instability can generate all kinds of noise. Most of the ones on the market are actually pretty decent, I've found - but it only takes a dry joint to cause all kinds of problems. My favourite was a plastic cased Italian one a customer had a few years back that like one of the posts above, caused lots of noise that the squelch could not silence on an Icom VHF set. I tried it on an Icom hand-held not connected to the boat power supply and it worked perfectly. The black - cable created a dual path - the battery negative going to the AIS splitter AND the radio and this seemed to be the culprit - effectively grounding the thing through the cable screen and the power cable - which of course the handheld didn't have. The actual cure was not really a dry joint - but was the internal ground tag on the splitter RF connector which had become loose and a bit corroded. Cleaning and tightening the bolt fixed it. A weird one.

 

[Sandy]

I have this same issue



where did you add the chokes? onto the power lines?

Yes. as close to the radio as you can get them. Every VHF I've fitted has always come with them and instructions.