vhf ariels

[TJAGAIN]

being new to the game i wonder if anyone can suggesta suitable ariel for my radio an icomm302 it is to fit
on a 23 foot sailer at the masthead?
tony................

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[gjgm]

you should find its clear on the packaging. essentially sail boats need a different gain than powerboats to address the fact that being up the mast they need to be less "focused", as it were. Otherwise the signal is either being sent up into the sky, or straight down into the sea , as the mast swings about. Exaggerating of course. Brand wise, think you are getting into marginal differences... and somewhat depends what your local chandlery has....

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[William_H]

You should be thinking in terms of two aerials one for emergency which is not up the mast.
The concept of a different type of antenna for a yacht is new to me and I can't think of any good reason to do so. Some antennas are electrically longer than the standard quarter wavelength which gives more power and sensitivity at a lower angle ie less going up into the sky but I think most people use quarter wavelenghth antenna. VHF marine centres around 156.8 mhz which means a quarter wavelength antenna is about 17.75 inches long. You can if you wish make an antenna out of bronze welding rod 17.75 inches long connected to the inner cable of the coax and mounted with an insulator. connect the outer braid to the aluminium mast as close as possible. An alternative is to strip 17.75 inches of the braid off the coax so 17,75 inches of insulated centre wire emerges. push this up a piece of fibreglass fishing rod which is then clamped to the mast and again the braid is connected to the mast.
For an emergency antenna which doesn't have the mast as a ground plane you can fold back the coax braid so that there is 17.75 inches of braid over the outer covering of the coax. ( 3 layers, the inner, the outer braid then outside that the braid folded back). The folded back braid needs to be insulated from everything else and may be pushed up an old fishing rod that is more than 3 feet long. this can be clamped to the push pit or bought out for emergencies. You will not get as long range as the mast mounted one because of the greater height but it should perform ok (better than a handheld) and you will know it will work if the mast is lost. From a compulsive DIY regards will

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