VHF & FM ANTENNA

[alisdair4]

This has probably been asked a few times - but here goes.! Is it possible to combine the feed from the VHF antenna with that to both the (soon to be DSC) VHF and the FM Radio/CD which I wish to fit to the boat?

Alisdair

<hr width=100% size=1>"so long as all you want is a penguin’s egg"

 

[sailorman]

yes
i have one fitted, bought from local swindlery @ around £30 ish 3 yrs ago.
works v/good to ok but reception sometimes not brilliant in marina, we r in a hole @ LW

<hr width=100% size=1>Mines a Crocodile sandwich & make it Snappy

 

[William_H]

Before you go to the trouble and expense of a antenna splitter try a piece of wire on the F/M CD you may well find that the recption is adequate for your purposes. Use about 1 metre of wire from the inside connection of the F/M radio run horizontally along near the skin of the fibreglass boat. (disregard if you have steel aluminium or carbon fibre boat) regards will

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[alisdair4]

Will,

Thanks, A good thought - particularly if it saves money. Theoretically this would work better, I presume, if the bit of wire were bonded to one of the through bolts of the toe-rail?

Or is the alloy unlikley to be a good enough conductor?


Alisdair

<hr width=100% size=1>"so long as all you want is a penguin’s egg"

 

[ccscott49]

No, length of antenna for FM, doesnt need to be very long, I doubt, repeat doubt it would help. Think car antenna.

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[Robin]

West Marine USA list a 2-in-one connector that can be used for 2 aerials to one set or 2 sets to one aerial. I think it is made by Shakespeare and the cost was <£30.

<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>

 

[sailorman]

its already pre-wired, c/w plugs / sockets .
just insert between your v.h.f & existing antanna & takes minuites to install without tools

<hr width=100% size=1>Mines a Crocodile sandwich & make it Snappy

 

[gjeffery]

Its another connection in the transmitter antenna cable. Do the manufacturers give any information about the losses to be expected?

Rule of thumb is 3db loss (ie 50%) at each connection; so I would be wary of using a splitter and prejudicing VHF output for the sake of a broadcast receiver..

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[Robin]

The manufacturer is Shakespeare who have a good reputation I believe for quality aerials. There are no figures quoted for losses in West Marine's catalogue, there are 2 versions an automatic one at $74.99 Model 159389 and a manual one at $34.99 Model 528786. The automatic one needs power and takes a current draw of 200mA.

<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>

 

[fireball]

Do you really need an FM Antenna at the top of the mast?
We've just put in a Radio/MD player and purchased a basic car ariel (~£8) and cabletied it upright in the tall locker that happens to be next to the nav station.

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[Robin]

Not really. In the past I have even used a car aerial laid horizontally under the cabin headlining and found it fine on AM/FM. We inherited a masthead AM/FM aerial on our current boat and whilst we get excellent FM reception (can receive Brit sations in Cherbourg even) the LW reception at long ranges isn't any better than the previous under headlining one. Poor LW performance doesn't bother me much anymore as the Shipping Forecasts are about worthless these days, even if they are not actually cancelled or delayed for unbelievably booring cricket commentaries.

<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>

 

[gjeffery]

Re above. Apologies, insertion loss nothing like 3dB at VHF. More likely 0.2 dB !!



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[alisdair4]

Thanks all,

Deduction therefore is to "Keep it Simple, Stupid" and go for the Car antenna.

Alisdair

<hr width=100% size=1>"so long as all you want is a penguin’s egg"

 

[hightech]

Avoid antenna splitters like the plague, they often upset transmission from your VHF sufficient to kill distance quite considerably. They upset the SWR badly.

If your set is a DSC version then it could mean the difference between an emergency message you send not getting through!!

Some VHF sets will complain at their use!

While I am on this, VHF antennas are the least appreciated part of a VHF installation and often bought cheap, again a big mistake. You pay for what you get!

Oh yes, ad contrary to popular belief VHF antennas have a limited lifetime 5ish years is not uncommon before they need replacing with new and make sure you solder a decent plug on when you swap out!

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[broadcaster]

Hi,

I thought that it was decided that soldering connections was not a good idea due to oxidisation and it was better to crimp now.

Andy

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