Which antenna? (noob alert)

[The Pan]

Hi all, totally fresh here. I'm a complete noob to boating. Just bought my first boat, a secondhand Stacer 509 Searunner (5.14m hull half cabin). The boat did not have a fixed radio (just a handheld) but i intend to be taking the family to the Keppels (off Yeppoon in CQ), about 10nm off shore, and I didn't want to rely on a handheld so I bought a GME700. For starters it will be just family trips ( so "good" weather) but the future might see me fishing. I still need to buy an antenna. So here goes for anyone who would like to help:

1. I'm thinking I need to be able to transmit/ receive to/from the coast (10-12nm) if need be. Or not? Are there any re-transmitters that reduce the distance I need to consider? Any locals here to advise? All following questions are dependent on that I guess.

2. Are 6dB/dBi/dBd worth considering? Assuming I don't get myself in rough weather. Define rough...What swell height for my type of boat? Remember we're talking about 12-15 nm max from shore.

3. Boat's already got a collapsible bimini. I'll be dropping in when parked so probably a fold down antenna? So how high? It seems I'd need a 20m antenna to get the distance ( https://www.jpole-antenna.com/2012/0...ommunications/ ) but that can't be right, so where am I wrong?

4. I've read that a fiberglass antenna is not really as high as the cover, so why choose one instead of a whip?

5. Buy one that comes with the cable or buy the cable separately for better quality? Or does it really not matter for the 3-5ft I'll need to the radio?

I'm quite happy with following links to educate myself, just the ones I've found so far haven't quite done it for me.

Thank you in advance.

[Dignity]

My knowledge in this area is very limited but personally I wouldn't put an antenna on a fold down bimini. I went for a 6db 2.4 m fibreglass mounted on the side of the cabin, forget the reasons now but something to do with the way the signal is promulgated (cant think of a better word)like a horizontal figure 8 and even the rock and roll of the boat can affect your transmission/reception and (don't quote me) but I think a 20m antenna the effect can be worse.

My antenna is with a separate cable but from experience very few are well sealed in their connections so where the cable enters the fitting I've added extra sealant and even on the antenna itself added dual wall heatshrink to prevent any moisture entering as this affected my last one even though it looked perfect from the outside.
You can get aerials for your mobile that extend your range quite considerably which in your area may or may not work.

As you say you need some advice from your locals.

[shortthenlong]

Have a look here

http://www.ausfish.com.au/vforum/sho...off-your-targa

Blokes who are local to your area

Just skip over the bits about sample size, there is even a mention of local shops

Cheers Matt

[Dignity]

Have a look here

http://www.ausfish.com.au/vforum/sho...off-your-targa

Blokes who are local to your area

Just skip over the bits about sample size, there is even a mention of local shops

Cheers Matt

Matt, I did a quick search for that post but for some reason it wouldn't show but some good stuff in there.

[CT]

Have a look here

http://www.ausfish.com.au/vforum/sho...off-your-targa

Blokes who are local to your area

Just skip over the bits about sample size, there is even a mention of local shops

Cheers Matt

I wouldn't trust those pricks!

[The Pan]

I wouldn't trust those pricks!

You probably know better, lol!

[The Pan]

Thanks Matt, hadn't found that

[scottar]

Yes - 6dB antennas are worth considering but don't go any higher - the compressed radiation pattern can cause broken transmission in heavy conditions as the vessel pitches and rolls. Most of these come in a 2.4 metre package which is by far the most popular antenna size for trailerable fishing rigs. Some of the cheaper brands do indeed have a short antenna inside the whip. The 6dB offerings are usually a colinnear array (basically two or three antennas electrically arranged to function as one - hence the higher gain) and as such there will pretty much be antenna in there and not much else. Quality brands like ZCG Scalar, Glomex, Shakespeare, Comrod (and others) will all have an offering. The Glomex RA1225HP is a great antenna - but pricey. Personally not a fan of cable and base separate to the whip - yes they are convenient but I have seen way too many corrosion issues. As for your distance. VHF is regarded as line of sight. The antennas you are talking to - usually VMR or a repeater are typically elevated - hence the better range. Yeppoon Coastguard monitor channels 21,22 and 82 which are duplex channels for repeater operation so at a guess there are repeaters in the location. I would contact them for better advise as to which channels cover what geographic locations.

[The Pan]

Thanks Scottar. A mate provided a 2.4m GME antenna so I'll be alright. And did talk to the local Coast Guard, so now just add water!