# Lowrance Transducer Question



## ReelTimeWes (Aug 20, 2009)

I am currently running a Lowrance X510C with a transon mounted transducer. I primarily troll Lake Erie for walleye. my unit sometimes picks up turbulance from the prop and also does not mark fish well at much above trolling speeds. I am thinking of switching to a shoot thoot thru transducer to eliminate the above mentioned problems. Lowrance makes a shoot thru ducer with a seperate temp. probe. Has anyone used this ducer with good results? I can get a new one for about $70.00.


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## Workdog (Jan 10, 2007)

I don't know about the Lowrance shoot thru the hull, but Airmar makes a nice shoot thru in the P79: http://www.airmartechnology.com/airmar2005/ex20/RMProducts/ElectCat.asp?ProdID=52&Man=All&PageNo=99 This comes with a tank so you don't have to fiddlefart around with epoxying the ducer to the hull (I've done that in the past and the results weren't great), and it's easy to align the beam to shoot straight down regardless your deadrise. You can get the P79 with a Lowrance connector on it, and, buy the Lowrance temp probe seperately. Currently, I'm running an Airmar B60-20 thruhull ducer with the temp probe self-contained. I read bottom as fast as the boat goes and read fish up to at least 35 mph. I have never broke lock with the bottom, and I've been in 7+ footers the last two years since I installed it: http://airmartechnology.com/uploads/brochures/b60.pdf Best price for these can be had at ByOwnerElectronics (BOE): http://www.boemarine.com/default.aspx


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## BlueMax (Dec 3, 2006)

I need an explanation regarding the thru hull ducers. Why are they so much better at showing bottom and fish at speed than a trannsom mounted ducer?? Is it turbulance? i have been trying to understand the theory but I come up empty.


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## Workdog (Jan 10, 2007)

BlueMax said:


> I need an explanation regarding the thru hull ducers. Why are they so much better at showing bottom and fish at speed than a trannsom mounted ducer?? Is it turbulance? i have been trying to understand the theory but I come up empty.


Gene, I think some hull designs are better for transom mount than others. An aluminum hull will usually have a couple rows of rivets at the transom that cause turbulence. With glass hulls, I think as the water exits from under the hull at the transom, there is a boundary layer separation that causes some amount of verticle turbulence which can cause air bubbles under the face of the ducer. Perhaps the amount of deadrise affects turbulence, as well as the proximity of the lower unit plowing through the water. I think boats with motors setback from the transom (such as on brackets) may cause less turbulence for the transom mounted ducer. And, turbulence means sonar-robbing air bubbles.

Thru hull and shoot thru the hull ducers are mounted forward of the transom and avoid transom turbulence. Even with these two types of ducers, you still have to avoid turbulence-generators such as strakes and water pickups. Therefore if you go with one of these type ducers, you must very carefully choose its location. Given the same output transducer, a shoot thru the hull ducer will be less sensitive than a thruhull ducer due the fact it has to shoot thru fiberglass and whatever medium the ducer is mounted in. Lowrance says you can mount their ducers in a special epoxy to the floor of the bilge. Done incorrectly, there may be bubbles of air in the epoxy, or in the fiberglass hull. 

The Airmar P79 is nice in that it has a "tank" that is first bonded to the hull, then an oil or antifreeze solution is poured into the tank before the ducer is mounted in the tank. The ducer can be rotated so that the beam is oriented straight down (unlike an epoxied ducer head which is usually oriented to the deadrise of the hull).

I prefer my Airmar B60 thruhull transducer to achieve best sensitivity and picture. The biggest disadvantage of course is, you have to drill a 2 3/8" hole in your hull. You better be damned sure of the location before you start drilling. The face of the B60 is nearly flat, causing no turbulence as the water flows over it. Inside, there is a "tilted element," in my case 20 degrees, which perfectly matches my 20 degree deadrise. The B60 also contains an internal temp probe which negates the need for a screw on probe requiring another intrusion into your transom.

My hull will just not allow the sonar to read at above trolling speed with a transom mount transducer. I've tried lowering it, tilting it, moving it to other places along the transom, nothing works. My thruhull ducer allows me to read bottom at any speed, any water condition. Period. YMMV


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## BlueMax (Dec 3, 2006)

Thanks Jeff.


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## rickerd (Jul 16, 2008)

Workdog,
Thank you for your wealth of information on this. I would love to upgrade my transducer from my transom to thru hull. However that scares the heck out of me to do it myself. Do you know anyone on south shore of lake erie that you would recommend. 
Rickerd


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## Workdog (Jan 10, 2007)

rickerd said:


> Workdog,
> Thank you for your wealth of information on this. I would love to upgrade my transducer from my transom to thru hull. However that scares the heck out of me to do it myself. Do you know anyone on south shore of lake erie that you would recommend.
> Rickerd


I did mine myself. Try Freebyrd (Steve Carlson). He has posted on transducer installs in the past. His marina can probably hook you up, or give you a lead.


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## rockytop (Mar 19, 2008)

jeff are you getting good hooks when trolling, i wish airmar made a ducer with a wider beam. the 200 side is only 11 degrees and the 50 side is wider like 35 degrees. do you ever use the 50khz. also at high speed can you mark bait balls and lone walleye. bob


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## rockytop (Mar 19, 2008)

here is how the thru hull is done.


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## Workdog (Jan 10, 2007)

rockytop said:


> jeff are you getting good hooks when trolling, i wish airmar made a ducer with a wider beam. the 200 side is only 11 degrees and the 50 side is wider like 35 degrees. do you ever use the 50khz. also at high speed can you mark bait balls and lone walleye. bob


Bob, the faster I go, "snow" begins to appear on the scope. I think I am getting "snow" from electrical interference from the motors at higher rpms. At 35-45 mph, a lone Walleye might be hard to pick up. But, slower than 35 mph I wouldn't have any problems. I have my LCX-37C set with high ping speed and sensitivity to mark fish at speed. I use my SITEX 106 CRT tuned for trolling speeds to mark hooks better at trolling speed. I don't generally use the 50khz setting (I would if I took the boat offshore of VA Beach or Oregon Inlet).


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## Alwsfishin (Apr 5, 2004)

Finally posting this project....went just as the video showed....one for my Lowr 38HD w/broadband sounder and one for Furuno 600L.


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## Workdog (Jan 10, 2007)

Drilling those big holes can be a real nail biting event...  Finding the right location is the key to success. Good luck with the install!


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## Hetfieldinn (May 17, 2004)

I have a through hull transducer on my rig. My transducer is inside the hull in a bed of epoxy. I'd never go back to a transom mount ducer again. I don't lose bottom, even at 55 mph, and can mark fish at up to about 30 mph. It still marks fish with nice, thick hooks, and still shows perch as a bunch of tiny hooks.


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## Alwsfishin (Apr 5, 2004)

Found this finished pic last nite....4' forw of the tramsom.


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