Running 2 AIS engines from one ariel

robbieg

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I have a dedicated VHF ariel for a AIS engine (ie receive only) and want to and another engine to it. Is there a simple bit of kit which allows me to do this-VHF splitters are quite expensive because they allow transmit and I only need the receive function. Google hasn't helped to much-anyone point me in the right direction?
 

Salty John

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I don't know why you want to have two AIS engines, but if it's for redundancy then you need a manual two-way antenna selector - there are various makes available. With this arrangement you manually switch from one engine to the other as required. You can also get an automatic two way selector, but this is designed for one antenna to two radios and is switched automatically to the radio on which the mic is keyed - I don't see how this would apply in your case.
You could also simply use a BNC Tee-piece - see Index Marine for instance - the cheapest solution, but I'm unsure what the effect on reception would be.
 

lenseman

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You need a 'tee' piece as sold by RS Spare (or Maplin)

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=5464948#header

Wherever you purchase, make sure it is 50 ohms and not 75 ohms. Basically, 50 ohms is for radio communications and 75 ohms is for domestic radio broadcasting and TV.

The device mentioned by shmoo will not work as it is designed to isolated one port from the other and only allow one to work at VHF and the frequency is 100MHz and not 156MHz. You won't damage anything, it just will not work effectively and will be a waste of money.

If you are attending the Mercury Meeting 2009 and make yourself known to me, I will bring one down for you (for free). /forums/images/graemlins/ooo.gif
 

William_H

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Yes being AIS where signal strength is not a priority you simply connect the 2 input sockets together to the antenna. ie use a TEE piece for whatever type of connector yop are using. You may reduce the signal to something like half the voltage but that loss will never be noticed. good luck olewill
 

robbieg

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Yes but you will need a proper signal splitter-see JG Technologies, Cactus etc-tend to be quite costly. Used to be an argument about whether it was wise to rely on a splitter to protect the integrity of your VHF and a better solution may be 2 ariels-one being dedicated to the VHF
 
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