VHF Antenna

[Hunter757]

Well got a new to me boat and have installed my FF, downrigger's and getting ready to add a VHF radio. I need to know what length is better and why? I want to install a Shakespeare 4' XT on a SS ratchet mount. Now the question is go with the 4' or should I install the 8' antenna? They make the one I want in both lengths and know that the shorter is only 3db gain and the 8' is 6db gain and I understand the value there.

The VHF radio is a brand new raymarine 49 if that matters. Also I see them mounted on port and starboard and my guess is personal preference?

I will use my boat on Puget sound and lakes. Not heading offshore as I don't know the sea all that well so I will stay closer to shore. My boat is 2005 Weldcraft 182 DV.

Thanks!!

[Larry3215]

Well, longer is (almost) always better in VHF antennas - assuming equal quality.

Better means more range and better call quality. VHF is line of site, so you send and receive further the higher the antenna is mounted and the taller the antenna is above the water. If you're only talking to boats in your local area its usually no big deal.

On the other hand, if you're in an emergency situation and really really NEED to reach the Coast Guard RIGHT NOW, then the longer the antenna (and the higher its mounted on the boat) the better chance you have of getting through. Depending on where you are there may be islands, hills, etc in the way even in Puget Sound.

On the flip side, the longer antennas can be more of a pain and more in the way when folded down. They also may need extra support when folded and driving to keep them from whipping around.

As far as mounting port or starboard, I always decided that based on a combination of wire routing and access to the boat when the antenna is folded. Sometimes they are more in the way when in the down position on one side vrs the other. However, shorter antenna wiring is always better, so I try to keep the wire run as short as possible.

I havent looked at VHF radios in a long time and am actually about to start shopping around again for a new radio for the new boat. Does the one you picked out have DSC? I was told recently that the price difference has come way down to add that feature.

[G-Man]

It really comes down to your personal preference in dealing with one size over the other. Larry pretty much laid it out for you, without going into the physics that drive it all. A 3db gain is basically doubling the power output, where 6db would double that output yet again to 4x.

If you want the science behind it check out http://continuouswave.com/whaler/refere ... tical.html

I worked in the radio field while in the service. I didn't put a whole lot of stock into an antenna's db rating, as a high rating can be achieved but typically results in a focused or narrow field, which is great if one of the targets is stationary. For the marine VHF band, 156Mhz to 162Mhz is your wavelength and equates out to about 6' 3" give or take a few fractions of an inch. Cut that in half to get you a standard 1/2 wavelength antenna and you end up with 3'. However, because of a lack of ground plane while on the water, marine antennas need to pull a few tricks to be efficient. The 8' antennas are essentially two half wavelength antennas arranged in a manner to provide amplification in a desired pattern. The 4' antenna's lack of a second 1/2 wave antenna results in a lower gain but a more even field.

[Hunter757]

Larry, yes this has DSC and I picked this one up at a price that was hard to say no to. Yes both antenna's I am looking at are shakespeare extra tough made to take a beating. Sounds like the longer one is the better bet, I will walk around my boat with a tape measure and see what I come up with.

G-man, your right on the money and I understand the gain as I am into cb radio. I just like the shorter antenna as it would fold down out of the way during summer when on lakes as the longer one would be in the way a bit unless its up. The port side is a good choice for me as I have the space to mount it and the aluminum boat allows easy running of wires as I have been busy with the other items and running wires down both sides. When you run coax you want to keep it no shorter then 6ft and then 3' from then on and if you need to coil it up that is ok just do it close to the radio as possible.

I look at a ton of pictures online to get ideas on where to mount and how they look once installed. Saves me from moving or drilling extra holes in my boat. Now to order up the new antenna and get them installed. Thanks guys for your input, anyone else who cares to chime in please do.

[BARCHASER10]

8' with a metal base. The ones with plastic bases don't last. They all fold down out of the way, so why not go with the longer one? I don't have my 8 footer up when I fish in the lakes and its out of the way.

[Larry3215]

Hunter - where did you find the great deal on the radio? Im shopping DSC is a must for me and the best Ive seen so far is around $235 on-line.

[Hunter757]

Barchaser, I have not bought my antenna yet but I am leaning towards the 8' one, yes on the SS mount only way to go along with the ratchet mount to fold out of the way.

Larry, I like ebay and can always seem to find a great deal. You also depending on where the seller is located can avoid the extra costs of buying in state (taxes). I picked up mine brand new for 160. If you look sometime daily you can find what you want for cheaper then you can buy it local and the warrenty is with the factory not the store.

I like raymarine radios always have, but the new lowrance link vhf radio almost got my vote. They have the link 5 and link 8 model and worth a look and the cost is not bad. There was a guy out of Canada selling the 5 for a great price but in the last week he up the price on shipping by 15 bucks making it overpriced, his orginal price was 165 to your door. They key is to watch for a great deal and know what you want then wait and find guys willing to accept best offers you can really save a few bucks that way. What radio are you looking at now?

[hewesfisher]

Radio - http://www.ultimatepassage.com/cgi-bin/up/40515.html" onclick="window.open(this.href);return false;

Antenna - http://www.ultimatepassage.com/cgi-bin/up/15434.html" onclick="window.open(this.href);return false;

Mount - http://www.ultimatepassage.com/cgi-bin/up/13724.html" onclick="window.open(this.href);return false;

Searching for pics now...

[Larry3215]

Thanks for the info and links guys. Standard Horizon is what Ive always owned. My Eclipse must be going on 20 years old at least and still works well, but wont quite fit where I want to put it on the new boat. Sold it when we bought the new boat last year. That compact model you linked to Hewesfisher is one I was looking at last night. Thats a fair price too. The $30 rebate helps

[Hunter757]

Phil, nice pictures I love they way the radio and troll are mounted flush looks really clean. I have one question where did you get the coax water tight seal for the side of the boat? I will be needing one of those and have not found one yet.

I measured my boat out and if I install a 8' antenna in the same spot as the picture about when I lay it down it will hit my downrigger and not lay flat. I think it may be in my best interest to go with the four ft and get the 2' extention or just run the 8' in the up postion.

Thanks,
Eric

[hewesfisher]

West Marine for the waterproof clamshell fitting. I also routed the coax through the mount vs the side of the ferrule (black plug just forward of cam lock) for a cleaner install and less flex.

I had a similar concern about my downrigger mounts, but turns out it was a non-issue in my case. Pick up some of these rubber clamps from West Marine too, they work very well with a little trimming so the antenna slides in easy. I attached it with 3M foam tape vs screws.

What I like about the GX1600 is the large LED display, DSC, and compact size. Works great on our boat.

[Hunter757]

Phil, guess its time for me to take a trip to West Marine good thing there right down the road from me. I love the design of your helm very nice set up the guys at Hewescraft gave that some thought very nicely done. I like the clean route of taking the coax out the mount and your right less stress is always good on a coax. I like the tip mount as well I will need to get the wife outside when my mount arrives and measure it's placement and see if I can sneak the antenna in there like you did, very clean and simple.

I will post some pictures when I have mine installed. It might be a week or so as the boat is going to the shop on Tuesday to remove that ugly bottom paint or what is left of it. I will be putting more elbow grease when I get it back to make it shine as I love the look of bare aluminum then I will put some shark hide on it and retreat every couple of years as needed.

Thank for the pictures and ideas Phil I know it takes time to do that and most guys are not willing to go that far so I say thank you. Tight lines, Eric

[hewesfisher]

You're welcome.

Oh, I should add, other than the steering wheel and larger panel on the right, I did everything else including the small 3 switch panel at lower left.