Transducer set up (ct100)
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Printed Date: 27 Jul 2026 at 7:59pm
Topic: Transducer set up (ct100)
Posted By: Pleasuretime
Subject: Transducer set up (ct100)
Date Posted: 05 Mar 2015 at 8:24am
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Raymarine I have recently updated my boat to the latest raymarine gear E display Ct100 chirp Cp450 2kw chirp (in hull transducer) HDRadar I can't get my ct100 down scan to perform as it should. To start with the mounting method is really second rate ( flops around as you can't tighten it up. The slow performance is great ( below 8 knots ) depth and picture disappear at speeds over this. Initially mounted as per instructions then after talking to lusty and Blundell, lowered it 25mm. I then packed it out from the transom 20 mm .... No good http://www.johnnyraysports.com/JR3install.html I have ordered one of these to try Does anyone know of a successful install of a ct100 down vision I can get some tips from? Any other suggestions ? Thanks Michael Parker 021 958820 ------------- Michael |
Replies:
Posted By: Steps
Date Posted: 05 Mar 2015 at 9:09am
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Flop around.. think u will find they do... bit of tolerance if hit something I think the reason is...ie no water at the ramp sitting in mud... set height and angle with at the top of the flop... Position on the stern .. look up under the hull for any ribs, places that air can be drawn in from the bow , down under the hull out under the stern... postion MUST BE where no air MAY go in the area of the transducer.....even 1" either side can make a huge difference The other reason for interference is inducted electrical interferance from the transducer and its cables being routed too close to other cables.. ideally it should be on the opposite side of the boat to the other looms or at least 10" away. Interference and air will give the symptoms u describe above. All assuming the unit is at least set to default. After all the messing around, moving, asking questions, research I had to do to get my transducer right.. and Im talking over 30 mph....came down to the above. The best bit of research was looking at the same boat at ramps and trademe as to where they located on the stern. That extender, in my opinion would not waste my time.. looking at that u are far more likely to pick up air and also prop interference. Make sure the cables are outed secure and well away from anything else before even messing with mounting. |
Posted By: kaveman
Date Posted: 05 Mar 2015 at 9:18am
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Agree with above.. that extender is not what is needed. Try and position down scan transducer as "close" to centreline of hull as possible( making sure there is no stakes etc in front off) I run a garmin downvu/ sidevu unit and get great screen shots but they do not perform well at speed PS. what hull have you got? -------------  www.kavemantackle.co.nz
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Posted By: Steps
Date Posted: 05 Mar 2015 at 10:05am
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"close" to centreline of hull as possible interesting.. the manual etc says starboard side of the motor and x distance from prop...which means away from the keel....if one has a keel Mine has ended up closer than the factory recommended into the prop thu not to close to the center approx 15".. the though did cross my mind to put moreto the center behind the prop.. but that could mess up very slow speeds maybe...??? |
Posted By: Pleasuretime
Date Posted: 05 Mar 2015 at 10:53am
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Thanks for the quick replies. I have a Tristram Grandurer 9m Mercury 370HP V8 diesel with a bravo stern leg  ------------- Michael |
Posted By: Pleasuretime
Date Posted: 05 Mar 2015 at 10:54am
------------- Michael |
Posted By: Pleasuretime
Date Posted: 05 Mar 2015 at 10:55am
------------- Michael |
Posted By: CoastalStan
Date Posted: 05 Mar 2015 at 11:58am
| I have set up two of these on two different boats and can tell you that the only problem is it is way too low. And there is a screw that tightens it up. As a basic guide if you look at the front of the bulb there is a mold line that goes around it. That needs to sit level with the highest point of the hull. I travel at 24 knots and get perfect reception in all depths. the water from the hull needs to brush over the bottom of the transducer. Also mine sits level, not according to the instructions but tested it and it worked so never changed it. |
Posted By: Pleasuretime
Date Posted: 05 Mar 2015 at 12:37pm
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Thanks Stan. This is how I first set it up. Similar to what you suggested? 
------------- Michael |
Posted By: Pleasuretime
Date Posted: 05 Mar 2015 at 12:40pm
------------- Michael |
Posted By: kaveman
Date Posted: 05 Mar 2015 at 12:43pm
I can see why yours is setup like that with the stern leg Steps, what does your readings on the Port side look like? Not very good i would assume The reason you need to get it as close to centre of boat as possible is with sidevu, you will not get a good sounding on one side of your boat. You can fit 2 transducers (1 each side of hull) and use a special Y shaped connection that works with 2 transducers compared to using 1 transducer Every boat is different in bottom shape etc so no "one" guaranteed fit for all boats. The optimum placement is the same as placement of a normal transducer,(through hull) but naturally 2 transducer will be needed for sidevu unless you have a flat spot on centreline with no turbulence in front of transducer. Will take photo of my setup on Surtees 6.1 ------------- www.kavemantackle.co.nz
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Steps wrote:Posted By: kaveman
Date Posted: 05 Mar 2015 at 12:49pm
 Surtees have a special plate to fit transducer, fitted the structure scan as close to center of boat as possible. Pleasuretime.. that bottom photo seems like a good trans setup  mine might look low in the pic above but it is only just below hull line------------- www.kavemantackle.co.nz
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Posted By: Pleasuretime
Date Posted: 05 Mar 2015 at 1:05pm
Thanks Guys, My transducer is a CPT-100. has down vision ie not side vision so ok on one side. Works great at slow speeds.CPT-100 Transom Mount CHIRP Transducer
------------- Michael |
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Posted By: Bay Marine Electronics
Date Posted: 05 Mar 2015 at 1:37pm
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Tristram Grandurer 9m. Planing strakes. Talking to lusties last time I had an issue with these transducers - they are apparantly designed to sit entirely under water "Torpedo" like. ------------- 0800 BAY MARINE www.baymarineelectronics.co.nz |
Posted By: CoastalStan
Date Posted: 05 Mar 2015 at 1:55pm
| That is how I originally set up mine but had the same problems as you. Moved it up 5-10mm and left it level and now is great. my boats at Mangawhai but you're welcome to check it out this weekend. |
Posted By: CoastalStan
Date Posted: 05 Mar 2015 at 1:56pm
| . |
Posted By: CoastalStan
Date Posted: 05 Mar 2015 at 1:58pm
They put out a great rooster tail if you do that! |
Posted By: Steps
Date Posted: 06 Mar 2015 at 7:40am
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I can see why yours is setup like that with the stern leg Steps, what
does your readings on the Port side look like? Not very good i would
assume Mines on the starboard side, and an outboard... If too deep one ends up with spray going all over the motor.. not recommended and a wet back..... And designed to have the bottom 1/2 of the transducer only skimming the water, as per manufactures instructions....which if wrong Im sure that world wide there would be far more controversy than there is. 2 things cause issues 1/ electrical interference.. as mentioned above 2/Air between the bottom of the transducer and water... flowing underneath Get 1/ 100% right 1st.. if thats not right 2 is just banging your head against a brick wall, and running around in circles. Then set up exactly was the manufacture recommends using a straight edge gong at least 1/2 m up under the hull surface to get the height (the seam as described above) right And study, look at the hull from the bow back, and think it through how any air that gets trapped by chines , ribs, strakes... including those that go from bow to part way down the boat.....1" either way can make a huge difference.... And u may actually end up placing on a strake, because the air trapped by it at the bow may flow from it to the flat areas of the hull... reducing friction... Which is why I had so much trouble getting the location right on mine If u need to go too low, I believe the reason why is that u have to get below the trapped air and location is slighly wrong I was fortunate that at some time in our boats life it had trim tabs...and was able to use these old screw holes till finding the right position... without making new holes. Couple pics I have posted before, from one of the instruction books I have here.. which are basically the same regardless of brand   |
Posted By: Pleasuretime
Date Posted: 06 Mar 2015 at 8:01am
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Thanks for all your comments Do you think because I get perfect readings at 8 knots ( sonar and depth) that I have no electrical interference issues? If this is true then I have a location issue only? ------------- Michael |
Posted By: Bay Marine Electronics
Date Posted: 06 Mar 2015 at 8:30am
I must admit it did sound strange when they told me ------------- 0800 BAY MARINE www.baymarineelectronics.co.nz |
Posted By: Steps
Date Posted: 06 Mar 2015 at 8:43am
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Do you think because I get perfect readings at 8 knots ( sonar and depth) that I have no electrical interference issues? No....bad assumption.....Us older guys who had old cars (and still do) radio interference was a constant issue... it low rpms one would get intermittent bits on the radio.. like the odd blip on the screen ....as the engine got faster these blips turned into white noise...voltages and currents increased, alternators produce more current, as with a heap of other stuff . Sounder install manuals make very strong points about routing cables for very good reason.. to the extent of suggesting to route down the opposite side of the boat that the main looms run down.. in many cases |
Posted By: CoastalStan
Date Posted: 07 Jun 2015 at 5:38pm
Have you got this sorted out yet, here's a shot of 20knts in over 80m of water with the same transducer. |