Improve RF setup

[SimonNZ]

Hi all

Our Beneteau Oceanis 400 has some old RF wiring that I'd like to check is as good as it can be. This is the current setup.




The powered duplexer is old and rusty, I have no idea if it's actually doing anything or has just failed-over to passthrough.

The FM receiver works fine, as does AIS TX/RX.

1) I see 20 or so vessels when in the marina if it's busy and have seen other boats as expected when at sea
2) I can see my own boat picked up by other land-based receivers via MarineTraffic. The AIS splitter has a relay that switches in and out for AIS transmission - this can be heard when the AIST 120 is making a transmission.

VHF seems to work OK. For the one conversation I've had out at sea (haven't had the boat long) things seemed fine though I'm surprised to hear nothing audible ever in the marina really, even the weather channel sounds quite poor.

Is there a better way of arranging the setup?

Everything is linked to a single masthead antenna. The solar bridge is probably 8ft from the water - I could fit an AIS antenna there, or on a spreader a few feet below the VHF antenna to do away with the AIS splitter and introduce antenna redundancy. We're only coastal sailing in the daytime, so we'd only need to think about perfect comms in heavy seas if we failed to check the weather and/or got really unlucky. The AIS side of things is as much of a hobby for me as anything else.

cheers!

 

[KompetentKrew]

Bin the powered splitter and just connect any old length of wire to the car stereo.

I don't know the optimal length for a random wire antenna - a wire coat hanger was de rigueur when I was a child, but you might find longer is better for longwave.

 

[SimonNZ]

Bin the powered splitter and just connect any old length of wire to the car stereo.

That's an excellent point, I was looking at the most complex scenario - this is much better. Coat hangers worked for me on my early cars but there are many little FM antenna solutions out there!

Thank you!

 

[Refueler]

Bin the powered splitter and just connect any old length of wire to the car stereo.

I don't know the optimal length for a random wire antenna - a wire coat hanger was de rigueur when I was a child, but you might find longer is better for longwave.

I assume you mean get rid of the Duplexor ?

I am trying to fathom out why the setup has a Splitter and then a Duplexor ....

Tried searching for specs on 5120 splitter but nothing came up .... is it a powered Active splitter or a non-powered passive ?

Anyway ... I would see if anyone you know has a VHF range SWR meter ......... this will check the condition of the antenna / cable / setup.

 

[SimonNZ]

Thank you!

Yes, I believe get rid of the duplexer was the intention and that makes sense. The FM radio is low priority and anything will work in a pinch - obviously for longer range the higher the better, but getting the best from the AIS and VHF is my priority, as well as tidying up old kit.

My diagram had a typo, well spotted and now fixed. It's an AIS S120, powered - it's sort of a smart splitter. https://www.gme.net.au/au/navigation-sonar/aiss120/

It works in conjunction with an AIS transceiver, also GME.

Ah a SWR meter. Good idea, it's been a long time since I used one of those. Will give it a look - cheers.

 

[Refueler]

I bought :

69.13￡ |Rs-50 Digital Swr/watt Meter Nissei 125-525mhz Uhf/vhf M Type Connector For Tyt Kenwood Baofeng Led Screen Radio Power Counter - Walkie Talkie - AliExpress

as replacement for one I have lost over the years .... I have similar need. I have been given a splitter to test (passive) and wish to see what losses / effects when installed.

My FM radio has a car telescopic cheap antenna up into toe-rail inside cabin - works fine.

Looking at your installation - and the splitter you have ... it appears that whoever setup that gear just wanted to add FM radio connection - and in so doing may have caused loss of performance. Given that you could actually just wire to a stay or add a simple antenna as I have for the FM ... I would be inclined to ditch the duplexor and test again.