I Need A New Marine Radio and Antenna...What's Best?

Epitome

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Sep 9, 2008
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I went to West Marine and saw what they had, but seem over priced. I have ordered stuff from Iboats.com and have always been satisfied. I need a new radio and antenna. I need a 4 foot fairly stiff fiberglass antenna so that when I fold it down for trailering it isn't flopping and hitting the boat. A radio that is 5" wide body and has a 6" front will fit in the dash just fine. I need just a good base marine radio and don't need to spend a fortune on it. I would appreciate experienced opinions on this. I see some antennas say am/fm and some say VHF. What is the difference?
 

John C in PA

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Re: I Need A New Marine Radio and Antenna...What's Best?

I know at least two basic differences between an AM/FM antenna and a VHF antenna: the conductor is tuned for the frequencies that you will be using (commercial broadcast vs. public broadcast) and the connector on the end of the cable to the radio.

The best prices I found for marine antennas is this outfit. http://www.consumersmarine.com/

John C in PA
 

Epitome

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Re: I Need A New Marine Radio and Antenna...What's Best?

I need a VHF radio right? May sound like a silly question, but this is my first boat with a steering wheel lol. I have been out 100s of times, but this is the first time I have to pay attention to the details.
 

Splat

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Re: I Need A New Marine Radio and Antenna...What's Best?

Purchase the best quality antenna you can afford. The quality of the antenna will greatly improve or reduce the usefullness of the radio. Don't get me wrong a good radio is important too, but the antenna is generally regarded as the important piece.

How large of a boat is this? You may not be required to carry a VHF if your boat is under 16ft. It's never a bad idea to have one tho. How far from shore do you typically go out?

Bill
 

Splat

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Re: I Need A New Marine Radio and Antenna...What's Best?

Forgot to add if you can go to a 8ft. Antenna. The longer the better if you can make it fit.

Depending on the height antenna you go with you'll probally want a 4db or 6db gain. Probally a 6db depending on the type of boat your putting it on.

Bill
 

Epitome

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Re: I Need A New Marine Radio and Antenna...What's Best?

It's a 20'4" boat and could take an 8 foot antenna no problem. What is 4db vs 6db? and what radio should I buy without breaking the bank? I will probably run a couple of miles off shore with it, possibly a little farther. We'll see, I haven't had it in the water yet :)
 

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triumphrick

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Re: I Need A New Marine Radio and Antenna...What's Best?

Si tex has been making marine radios for as long as I can remember, and their radios have all the necessary bands and functions.
Also agree on the 8' antenna. Usually available with a folding mount to drop down out of the way.
All this available here at iboats or off the 'net. Good luck! :)
 

Splat

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Re: I Need A New Marine Radio and Antenna...What's Best?

OK lets see if I can explain this to it's easy to understand.

db or Decibel of gain, is the appearance of signal gain with an antenna. An antenna of 8db of gain appears to collect and transmit the signal better than a antenna with 2db of gain.

Logic here would say then always go with the biggest db you can get. Like most things in life it's not that easy.

Think of the signal coming out of your antenna as a large doughnut. With a 2db gain antenna the the doughnut that the antenna sends out is large and round. so it covers a large area up and down, but not out.

Now take that doughnut and smash it flat. It's now thin and spread out. This would be a 8db gain antenna. The beam goes out further, but in a more focused pattern.

This is important and the trade off are important here because your antenna will always send the signal out perpendicular to the mast(antenna). So as your boat pitches and rolls the "doughnut" is moving with the antenna. If you have a high gain antenna the signal if very focused and won't always find the other radio.

Think of it like a flashlight shining at a specific rock on the bank, this rock we'll imagine for a second is the other radio your trying to talk to. When the beam is very focused(high gain like 8db+) it harder to get the light on that one spot, but it projects very far. Now take that same light and make it a flood beam (like a 2db antenna), it's now much easier to light up that same object, but the beam may not go as far because it's spread out. Same concept.

Very high gain antennas are normally used on base stations because they don't move around. Mid gain like 4-6db normally on power boats. The antenna moves around, but normally not huge, so the higher gain here is still useful. low gain (0-2db) are normally used on sail boats because the antennas are usually mounted way up high on the mast, and the movements of the boat are greatly amplified way up on top of the mast.

Hope this helps. I've been doing this stuff for years so I get it, but to someone that doesn't play with it all day long it can become very confusing very quick.

Bill
 

Splat

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Re: I Need A New Marine Radio and Antenna...What's Best?

After I wrote all that out I found the link I was looking for. This article is a little lengthy but it has good diagrams(easy to understand) and covers just about anything VHF Marine related.

This was posted by Dingbat back in September, so he gets the credit for it.

http://members.toast.net/boatguy/vhfant.htm

Bill
 

Epitome

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Re: I Need A New Marine Radio and Antenna...What's Best?

Your explanation of what could be a very complicated topic was clear and concise. I got it. The idea is that someday, with proper kicker motor, I may run up to 10 or 12 miles off with proper weather. Would the 6db still fit the bill if the vast majority of the time the boat will be less that 2 miles off? The folding antenna mount is already on the boat.
 

Splat

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Re: I Need A New Marine Radio and Antenna...What's Best?

6db is perfect.

The two antennas you have listed are both good choices. The differences are they way the signal is sent to them.

The cheaper one the 5101 I believe, is "end-Fed." This basically means that the signal is sent to the end of the radiator(the part inside the fiberglass that actually sends out the signal.) and is dispersed out that way. From the bottom up. These antennas are slightly "off balance" for lack of a better way to put it. Remember that doughnut we were talking about, it would be slightly jagged at the bottom, and the top. It won't really hurt the signal unless your at looooooong distances. Say over 10 miles. They use a "stud" basically a coil of wire at the very top of the radiator to help bounce the signal and keep it's proper shape. The signal being sent to the radiator at the end means more impedance at a higher voltage. But you really don't need to know that, other than the signal is a little less uniform.

The more Expensive one the 5102 is a true Di-pole antenna. The signal is fed into the radiator in the middle and radiates out the top and bottom evenly. This gives a better stronger more uniform signal. But it's more involved in the manufacturing process thus the added cost. I'm not going to lie to you, it's a much better antenna. Especially if you consider the chances that you may have to contact SAR aircraft if you get into trouble.

SO here comes the decision. If most of your time is spent close to shore, the cheaper one will do you ok. Even if you go out further from shore, but are normally around other boat traffic you could contact, the cheaper one would prolly do you just fine as well. But if your venturing out 5+ miles from shore and boat traffic is hit or miss, the better antenna is a better choice if you get in trouble.

It's more money sure, but a good antenna makes or breaks the radio. Personally I would spring for the better of the two. That's just my opinion.

Let me know if you have any other questions.

Check your PM's
Bill
 

Boatist

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Re: I Need A New Marine Radio and Antenna...What's Best?

You got a lot of good information. A 8 foot 6 db Gain antenna is the right size antenna for your boat.
Effective power out doubles with every 3 db so with 6 DB Gain you Start with the radio's 25 watts
it doubles to 50 watts with the first 3 db then to 100 watts with the second 3 DB Gain.

The two antenna you are looking at are middle of the antenna group.
They use Chrome Covered Brass for the mount.
That is very good in fresh water but I like Stainless Steel in Salt water.
The Stainless just looks better and holds up better in salt water.
Also both the antenna you are looking at use RG-58 Coax which is pretty high loss at VHF Frequencys.
However if you running very short distance like most people (Maybe 6 feet) then it should be fine.

The top of the line antenna like the 5225 XT or XP use Stainless Steel mounts and RG-8X coax which is lower loss. Antenna also Stifer and should hold up longer. Of course they are Higher cost.

Hard to buy a bad radio today as all are pretty good today.
I feel ICom is still the best.

Before you mount your new radio in the dash consider that new features come out on radios every 5 years or so and many upgrade to later models.
Uncommon for a new radio to fit the same hole as your last radio.
If you do dash mount it then you will want a front speaker or a external speaker mounted away from your compass.

VHF no longer requires a licence but you are still required to follow all the rules.
Know that you are required to monitor channel 16 when the radio is on and not in use.
Know that most channels have a single use and can not be used to just talk to anyone.
Example 16 is the Calling and Distress channel that the Coast guard and everyone else monitors. So Call make contact and move to a working channel.
Channel 22 A is for talking to the Coast Guard and 21 is Coast Guard only.

Also if you have not done so take a Coast Guard "Boating Skill and SeamanShip class" 13 week class is much better than the short class.

I also have a 14 foot open boat and a 21 foot Runabout that I use 50 percent off shore in the Pacific Ocean. Stay with in 35 miles of shore or from port.

I taken the Coast Guard Class 3 times and the US Power Squadrons class twice. Classes are fun and always learn something. My entire Crew has taken the Coast Guard Class.

Have lots of Safe fun with your new boat.
 

Epitome

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Re: I Need A New Marine Radio and Antenna...What's Best?

Thanks for all the help, you guys are great. I like to understand the details of things and you certainly have given me the details in an understandable way.

As you can see in the picture, the compass is up on top of the dash and I intend to mount the VHF radio down in the wood panel under the dash, next to the cassette/radio (which I plan to change). The Loran unit you see in the picture is getting a GPS/Depth Finder unit for the spring. I only want one electronic mounted up there. The only other option is to mount the VHF radio on the opposite dash, which is where I think the previous owner had it (it was removed when I bought the boat).
 

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tashasdaddy

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Re: I Need A New Marine Radio and Antenna...What's Best?

this is what i did on the toon. easily removed to go on other boats.
toonalmostfinished004.jpg
 

Epitome

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Re: I Need A New Marine Radio and Antenna...What's Best?

Deleted, question was too dumb lol
 

waterinthefuel

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Re: I Need A New Marine Radio and Antenna...What's Best?

A 3' mounted high will receive and transmit better than an 8' mounted low. Height is more critical than length. Airplanes have VHF antennas of about 12 inches long, but from 2000' can transmit 30+ miles on 5 watts.

Get that sucker up HIGH. Just be careful trailering an 8' fiberglass antenna. They can break the base off easily, or get whipping to where they break themselves.

Radio is irrelevant. They all have DSC or whatever that new distress thing is, so any radio from a known brand name is fine. The antenna is the big thing. Remember, a chain is only as strong as it's weakest link. Radios can only put out 25 watts, whether you pay 99.95 for the basic SiTex or 399.95 for the all you can eat buffet. Its what you send that signal out through and receive with is what makes all the difference in the world.
 

Epitome

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Re: I Need A New Marine Radio and Antenna...What's Best?

You can see the mounting base just under the end of the windshield. I have another just like it on the other side. It's about as high as it could possibly be and it will fold down for trailering.
 

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