Aerial combinations for car VHF radios on board?

Talulah

Talulah

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Currently the masthead has two VFH aerials.
One is connected to the ships VHF and the other to the AIS receiver and car stereo unit.

If I was to replace the AIS receiver with a transponder it would no longer be safe to have the stereo unit connected to the same aerial.

So what do you do?
Fit a third aerial, a splitter?

What other alternatives are there? How have other people dealt with this?
Any suggestions?
 
A masthead aerial seems a bit excessive for the stereo. For Kindred Spirit I bought a cheap car-interior antenna which I think was designed to be stuck along the bottom edge of the windscreen. it was a flexible strip with a self-adhesive back, then a short length of coax and a standard plug. Seemed to work fine. The old stereo on Ariam used an 8-inch rubber-duck designed for exterior mounting but just dangling in the space behind the chart table. Never really used the old stereo but I assume it worked. I may reuse that aerial with the new one, or I may fit another stick-on strip high up on the hull side.

Pete
 
My car radio (on the boat) originally had a rubber duck aerial on the pushpit, unfortunately it fell apart soon after I bought the boat. I tried a length of wire in the locker, but in my case it wasn't very good. Perhaps the location of the mooring caused a lot of interference, or maybe it's my boat. In a more affluent moment, I fitted a VHF splitter to the masthead aerial and the reception is superb. I understand all the objections about loss of signal on the RT, but as most of my time is spent within the Solent it doesn't concern me. I left the splitter accessible beside the VHF so if I have any concerns or prior to going offshore, I can take the splitter out in moments.

Of more concern is that the location of the car radio doesn't have sufficient depth for me to change the cassette player model for a CD player version!

Rob.
 
I used to have a home made diplexer sharing the second VHF aerial between the AIS (Nasa AIS 'radar') and the stereo.
It worked very well, no noticeable loss of range on AIS and very much better FM reception.
In those days I had the luxury of being able to use £50k worth of test equipment at lunch times...
 
rob2 said:
.....
Of more concern is that the location of the car radio doesn't have sufficient depth for me to change the cassette player model for a CD player version!

Rob.
Click to expand...

You could look at a 'mechless' one, which just does radio and MP3 from USB sticks and SD cards and lets you plug in a phone or other MP3 player.
I had a £35 ebay one branded 'Beat 175', half the depth of a CD player.
Did the job, but control software a bit clunky, they should have got better by now......
 
Talulah said:
Currently the masthead has two VFH aerials.
One is connected to the ships VHF and the other to the AIS receiver and car stereo unit.

If I was to replace the AIS receiver with a transponder it would no longer be safe to have the stereo unit connected to the same aerial.

So what do you do?
Fit a third aerial, a splitter?

What other alternatives are there? How have other people dealt with this?
Any suggestions?
Click to expand...
One aerial for the AIS,one for the VHF. Car aerial for the car radio, not aloft, no need.
Drift warning: Has anyone ever had the MW or LW of a car radio working properly, I never have, what is the secret?
 
jerrytug said:
One aerial for the AIS,one for the VHF. Car aerial for the car radio, not aloft, no need.
Drift warning: Has anyone ever had the MW or LW of a car radio working properly, I never have, what is the secret?
Click to expand...

On a car or on the boat?
My car last radio was poor on MW and LW. This was due to the head amplifier in the roof aerial. When this failed due to corrosion I bypassed it and the reception improved dramatically. Current car seems just about usable.
I have a car radio on the boat. AM reception is degraded by receiving interference from the depth sounder. Clicking drives me mad!
 
Ruffles said:
On a car or on the boat?
My car last radio was poor on MW and LW. This was due to the head amplifier in the roof aerial. When this failed due to corrosion I bypassed it and the reception improved dramatically. Current car seems just about usable.
I have a car radio on the boat. AM reception is degraded by receiving interference from the depth sounder. Clicking drives me mad!
Click to expand...
Thanks for your suggestion I will have a look
 
Talulah said:
Currently the masthead has two VFH aerials.
One is connected to the ships VHF and the other to the AIS receiver and car stereo unit.

If I was to replace the AIS receiver with a transponder it would no longer be safe to have the stereo unit connected to the same aerial.

So what do you do?
Fit a third aerial, a splitter?

What other alternatives are there? How have other people dealt with this?
Any suggestions?
Click to expand...

Digital Yacht do a 3-way antenna splitter: AIS/VHF/FM radio.

LOWRes_SPL2000_sml.jpg


http://www.digitalyacht.co.uk/product_info.php?products_id=11691

Installed one last October after the purchase of an AIS transponder.
Prior to that, the FM antenna was a bit of coax cable behind a panel - if we were lucky, we could get 3 or 4 stations.
 
I would never use a splitter. Aerials are cheap enough or easy enough to make yourself to allow for one for each system. I would be concerned about AIS and VHF com on one mast top. Just not enough spacing as com could damge AIS reciver with 25 watts possibly getting into the other aerial. far better AIS on the stern rail also useable as emergency com antenna.
For Am/FM radio there are real problems. VHF being 100 megahertz and MW being .5 to 1.5 megaherts and LW .2 to .4 megahertz. The compromise is huge to get all working well. Ideal isa very long wire for MW/LW and a 4ft aerial up high for VHF FM. There might be a lot to be said for using a car aerial and the cable to the radio. The cable is screened wire like coax but much less capacitance so finer centre wire. Length can be critical as the capacitance of this cable may for part of the tuning on MW.
Try just ordinary wire into the antenna socket. This will probably satisfy most people. If not then go for a long wire for MW/LW and a short wire up high if possible for FM.
Previous posters mentioned using coax. That (theoretically) won't work if the screen is earthed at the radio. Cut the screen you only need the centre core. good luck olewill
 
Beware the thread drift here, are AIS (Class B as well) splitters that bad?

I have splitter for stereo (not had an issue) already if and when I get around to a AIS Class B I have every intention of using the same ariel. The running back stays beat hell out of my GPS antenna as it is a VHF Ariel would just be asking for trouble, it would also stop anyone being able to use the ladder on the stern.

Another Ariel at the top of the mast could be a possibility, then I do not want to start carrying a small forest at the top of my mast.
 
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