Classic AquaSport
General Aquasport Forums => Electronics => Topic started by: fmaster360 on March 25, 2012, 10:07:23 AM
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I want to order a new GPS today or tomorrow, and I was hoping someone could explain how the transducers work. I had some difficulty yesterday with the transom mounted transducer for the fish finder that's on the boat. It seemed that when I was going faster in the wake, it would only show my dept as .9', as it was hitting the water and not going below it. I don't want to put any holes on the bottom hull of my boat. Can a transducer shoot through my hull, or do I need to cut a hole for it to go through? I'm thinking of the Garmin 541s or 441s unless anyone has something else that I really need to look at.
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Looks like the in hull is the one I want, but it's not looking like it's as accurate as the transom mount. Guess I'll just end up with the transom one. Gives me an excuse to clean up the shotty job of the last one's install.
I'm probably going to pick up the 541s on tuesday price matched at $575 from wm, a transom mount, and if they still have the blue maps on sale, those too.
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I'm a tad perplexed.....A GPS doesn't have a transducer so I have to assume your talking about a fish/depth finder or a combo unit. A transom mounted transducer should be mounted as far below the water line as possible and away from the propeller. Set it parallel with the bottom of the boat and just below it. The only holes in the bost are for the mounting screws. It you coat them with 4200 they will seal the hole on the way in.
You can mount one inside the boat and have it shoot thru the hull. I wouldn't recommend it because they tend the signal when your running hard. If you still want to go that route, then you must ensure the transducer is completely submerged in water and secured to the hull. There are several ways to accomplish this so if you need some help let me know.
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On an Aquasport boat, the best transom location seems to be 18" up from the center of the V in the transom. Your transducer will come with directions, but you want a clean flow of water over the transducer when underway. The good news - a transom transducer usually gets you temp with depth. :thumleft:
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Another question. I've decided on getting the 546s. I found one online wicked cheap. I can get two transducers, a dual frequency and a regular I guess. The dual one is for speed, and I assume that means it has a wheel. Is this more accurate as well? I can just switch the gps to use the gps speed and not water speed right?
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Dual beam is freaking expensive. I got the regular dual frequency. Hopefully will be here soon. I can't wait to install it.
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Another question. I've decided on getting the 546s. I found one online wicked cheap. I can get two transducers, a dual frequency and a regular I guess. The dual one is for speed, and I assume that means it has a wheel. Is this more accurate as well? I can just switch the gps to use the gps speed and not water speed right?
Never seen a transducer that has a "wheel" on it - the speed is from the GPS. Maybe the design allows less drag?
Who are you purchasing from?
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Plenty of them out there. Thru-hull or transom mount. Here is one. I had an Airmar thru-hull with depth/speed/temp for the Furuno bottom machine on my CCP. The Garmin 240Blue I had before that had a separate speed wheel that could be mounted on the transom mount transducer bracket or un-clipped and mounted separately.
Depth - speed - temperature transducer for boat (thru-hull)
20620011
(http://img.nauticexpo.com/images_ne/photo-m2/depth-speed-temperature-transducer-for-boat-thru-hull-218322.jpg)
http://www.nauticexpo.com/prod/comnav/d ... 18322.html (http://www.nauticexpo.com/prod/comnav/depth-speed-temperature-transducers-for-boats-thru-hull-21518-218322.html)
Mine was similar to this one.
(http://salestores.com/stores/images/images_747/A66091.jpg)
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Garmin makes a transducer that mounts inside the hull, a base is mounted then filled with oil then the transducer. It works awesome way better than any transom mount transducer I have ever had, even works on reverse and never looses the bottom signal no matter how fast you are going
Capt matt
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:thumleft:
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I posted this quite a while back. My CCP had this fiberglass well when I got it. I don't know if it was factory or added later. Fill it with mineral oil (or water but it evaporates over time) and ANY transducer dropped in there worked great at all speeds and attitudes. So did the giant Airmar (with built-in speed wheel) on the left.
Remember that "shoot-thru" does not work with a cored hull.
(http://img.photobucket.com/albums/v53/Johnny_B/Catch%2022/Catch22015a.jpg)
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Plenty of them out there. Thru-hull or transom mount. Here is one. I had an Airmar thru-hull with depth/speed/temp for the Furuno bottom machine on my CCP. The Garmin 240Blue I had before that had a separate speed wheel that could be mounted on the transom mount transducer bracket or un-clipped and mounted separately.
Depth - speed - temperature transducer for boat (thru-hull)
20620011
(http://img.nauticexpo.com/images_ne/photo-m2/depth-speed-temperature-transducer-for-boat-thru-hull-218322.jpg)
http://www.nauticexpo.com/prod/comnav/d ... 18322.html (http://www.nauticexpo.com/prod/comnav/depth-speed-temperature-transducers-for-boats-thru-hull-21518-218322.html)
Mine was similar to this one.
(http://salestores.com/stores/images/images_747/A66091.jpg)
Still not sure that I "get" why you would want one with a wheel. Could see if you don't have GPS/Chartplotter or the pitot in the lower unit like on my Yammy. Seems so "old", like the paddle wheel you mentioned that hangs off the transom. Maybe it's me, no - didn't mean I am "old" - well maybe .... :lol:
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Rick has a good point. Paddle wheel speed is notorious poor at low speeds, better at high...but both inaccurate. Pitot tubes are great at low speed, notoriously poor at high speeds...but both inaccurate.
Since we have GPS in our shorts these days, why not just go with that and ditch the old-fashioned...AND INACCURATE...stuff!
$.02 contributed...
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I wonder if you can disable the wheel, and use the gps for speed.
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People that do a lot of trolling demand water speed indication. GPS is speed over ground. If you want to troll at six knots and you are trolling into a 2 knot current the bait will not act the same as if no current. Going with the current you have to speed up to get the bait to act the same. With a paddle wheel just troll at an indicated 6 knots and you are good. People that never took the current into consideration think that a paddle wheel is inaccurate. I checked mine vs. gps several times when there was no appreciable current and found them to be dead on. They can be a PITA in the spring when there is all the floating grass getting tangled in the wheel.
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I wonder if you can disable the wheel, and use the gps for speed.
Yep. Just don't plug it in. GPS speed will be available whether the paddle wheel is connected or not.
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I've read the in hull transducers aren't a good picking up fish... Any validity to that?
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Carl,
If you want, you can read almost anything about everything! And they'll all be right!!
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Hahah! Good point.
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Carl in my little Panga I have a regular transom mount ducer mounted in the hull with clear silicon, I put a bunch down and mashed the ducer into it, thats it and it picks up fish great.
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Carl your going to like the 541 combo unit. Who had the good online price?
Keep in mind as you gain speed the sonar signal will degrade and the depth may become inaccurate. If you are getting the dual frequency transducer the 200 khz is for higher resolution in shallower depth. The 50 khz is a lower resolution for greater depth. I doubt your going to be in water deep enough around her for that to matter much.
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Carl your going to like the 541 combo unit.
I agree I bought the 541 chartplotter only with the blue chart built in (that's a must have) back in Feb and I love it, I already have the a Garmin 400 fish finder so I didn't need the combo.
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Keep in mind as you gain speed the sonar signal will degrade and the depth may become inaccurate.
I will have to disagree. It's all about installation no matter where it's installed. If the transducer is in clean water with no bubbles and angled properly it will read correctly. If one doesn't read at speed then it's angled incorrectly or something is giving it bubbles.
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I bought the stuff from Ultimate Passage. Cheapest place I could find. It'll be here Thursday, so I'm going to rip the old one out in the morning, Marine Tex the holes, and hopefully install the Garmin next Tuesday and take it out Wednesday or Thursday. Any of you guys ever go out during the week?
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This time of year I go out everyday lol
Capt matt
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I have a transom mounted transducer on my 250 CCP. It works great. Like anything else it must be installed properl;y to work properly. When you install it, Make sure the flat bottom of the transducer is level with the bottom. If it protrudes below the hull it will cause turb. and the FF will lose the bottom when you start moving.
(http://www.classicaquasport.com/gallery/data/500/1501ducer1.jpg)
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One other related question for you all. I installed a transom mounted transducer last season and it worked great. However, at the end of a season on a mooring it was covered with barnacles. What type of anti-fouling treatment should I apply this season to prevent those buggers from hitching a ride??
Thanks
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One other related question for you all. I installed a transom mounted transducer last season and it worked great. However, at the end of a season on a mooring it was covered with barnacles. What type of anti-fouling treatment should I apply this season to prevent those buggers from hitching a ride??
Thanks
You can paint the whole thing with the same paint you use on your hull. Some folks don't like to paint the underside where the beam comes through, but I've never had a problem with that. The old Coppercoat had a lot of metal in it and you would not want to use that, but most bottom paint today won't make a difference. Paint the cable also to keep some of those strange aquatic animals from eating on it. :thumleft:
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Cap,
Thanks so much for the advice. I was reluctant to take that step without some guidance.
Smooth Sailing!
Adam
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http://www.defender.com/product.jsp?pat ... 3&id=28012 (http://www.defender.com/product.jsp?path=-1|10918|296162|1017093&id=28012)
"No solvents to worry about.
The water-based formula will not attack the transducer face like some solvent based bottom paints."
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Does anyone know the angle of the transom on my boat? And on a side topic, can I use 5200 to fill in the old screw holes? They are pretty small, and I don't think they go all the way through...
Reading online, should I use the original holes, and then mount the new transducer on a piece of starboard?
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12 degree is the standard and what I have on a 222 FFV.
5200 could work in a pinch. I use epoxy to fill small holes. If you get the syringe type with a mixing tip you can shoot it in the hole. Then over fill slightly and use tape to hold it in. Then a light sand and done.
Since then, I bought a piece of starboard and made my own transom saver. I used that to cover all the holes on my 30 year old boat.
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If you mean dead rise, that would be 19 degrees from what I have found. If in doubt, you could measure.
I'm fuzzy on the starboard mount thing :scratch: so hopefully someone else will help with that.
Good luck.
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Transom angle is not deadrise.
Here is a diagram and how to caclulate it.
http://www.rocketflap.com/transom_calc.php (http://www.rocketflap.com/transom_calc.php)
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Very interesting. I'll measure mine to satisfy my new found curiosity. I'm sure there must be something to gain by knowing that number.
Must be why they make outboards with adjustable trim.
Learn something new every day.
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Thanks john!
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Transom angles are typically around 13-14 degrees. Use can also figure out transom angle and deadrise by using the Law of Sines, if anyone remembers back to their HS geometry days...
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Dang Bob you beat me to it! I think we had the sine discussion about three years ago on here and if I remember you blew everybody away with your recollection and how most of us had forgotten how to use it!
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I don't use Trig often but when I do.....
I prefer the Law of Tangents......
Stay ambiguous my friend. 8)
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Yes, tangent and specifically tan-inverse. Who needs a hypotenuse.
As for the need of knowing the transom angle, some transducers require the correct shim to install, that requires the angle.
Just installed a TM260 last week. Otherwise, I would not have a clue on the angle.
As for the starboard.....if you have a question let me know. It is easy to make.
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Let's see if I can remember - SOHCAHTOA! :cheers:
Sine = Opposite/Hypotenuse
Cosine = Adjacent/Hypotenuse
Tangent = Opposite/Adjacent
Man, that was in a back-of-the-head file folder... :scratch:
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Oscar (Opposite)
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Had (Hypotenuse)
A (Adjacent)
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Heap (Hypotenuse)
Of (Opposite)
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Apples (Adjacent)
Sine
Cosine
Tangent
In that order
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I got it installed, just drilled new holes. Came out nice. I stuffed some 5200 in the old holes with a syringe. Didn't think it would be nescessary to drill em out and put marine tex in this time since they weren't going to be tapped. I played with the 546s a bit, it's nice. The blue charts are cool, I guess. But not worth $240. Worth $40 I guess, if I get my $200 rebate back. Otherwise I'll be :evil: