Transponder for FCV-600L

[Nitroxwzrd]

Seeing the replies posted about bottom machines I was wondering if someone could help me out.

In case it’s not obvious I have a 600L, my problem is with the transom mount transponder I have. Above 5knts the bottom begins to break up and at 8knts I loose the picture. I was thinking about using an in-hull and was wondering if anyone has tried one, and if so how effective it was. I really can’t use a thru-hull since I have a cat and when I put my boat on the trailer it would shear off the transponder, since the sponsons sit on the bunks.

[IyaDiver]

It is called a transducer not a transponder....:D

I am assuming your boat is outboard powered.

My friend using a mono V hull have had great success by using IN-HULL, not thru hull.

IN HULL transducer installation is good when you are not keen for super deep reading. Power will be less by 20% but for diving purpose a 500 watt video sounder is goo enough at 80% power.
IN HULL will carry no risk of transducer being damaged by the trailer or whatsoever but make sure the boat bottom is 100% solid fiberglass. Fiberglass will act like water but coring of the hull with balsa or foam will not work with IN HULL installation.

IN HULL installation is simple and you can actually experiment without doing much damage. You need someone to drive your boat at cruising speed. Take a tough plastic bag and filled it with water. Keep the transducer in this bag and point it at a good angle to the sea bottom. Remember water is a must to make it work. Find the best area on the boat bottom by trial and error. For outboards installation, if the sea is calm and as tested in my friends 33 footer mono V hull, the video sounder a small colour CRT type Sitex ( 500 watt ) can read up to 30 knots and very sensitive too.

When you find a sweet spot , it is a simple fiberglass affair to make a box to contain the water and the transducer on the inner hull. My own installation on a 75 footer yacht used 50/50 radiator coolant for the liquid because I don't want regular water to grow algea or something. The video reading is not as great as my friend small 33 footer installation, but good to 20 knots, because I don't have the luxury to choose the installation spot at will, due to the yacht construction and many underwater sea cocks producing air bubbles up front of the hull. You can always use distilled water as the medium.

Good luck.

IYA

[Spearchucker]

Wow, thats an awfully complicated way. How about the way I have always heard:

Buy a big tube of silicone adhesive (3m-4200) and make a great big puddle in the hull, position the transducer in the puddle and let it set up. Make sure there are no air bubbles.

[IyaDiver]

YEP !!!! That sounds even better SpearChucker, that's new to me....:D I think it's a very good idea for small tranducer like the transom mount type. My installation was those bronze type transducer that looks like shoe size 7... he he he.

I like this new info...thanks !!!

[Nitroxwzrd]

Thanks for the info

The one I looking at you glue down, and will probably do it the way Spearchucker said.

I just wanted to know how effective they are compared to a thru-hull, the type where you drill a 1.5" hole into the bottom of the boat. I knew I'd loose some power and reception i just didn' know how much.

The transom mount might just be pissed off and fouling up since I've been calling it by the wrong name for tha last couple of months :o . Transponder / Transducer whatever :D .

[bgbill]

It sounds like the transducer is mounted to high and is getting interference, or air bubbles under it.

On my other bottom finders I always glued the transducer inside the hull to "shoot through the hull" like spearchucker recommended.

I did not do it with the Furuno because it has speed and temp. information.

[100days-a-year]

My Furuno reads up to 40kts when calm and 18-20 when it's rough.It does sound like there is cavitation caused by mounting to high,to lo or by a chine that is directing aerated water under it.The directions about mounting transducers at the transom are specific about placement for that reason.Do not use silicone to mount transducers as it further reduces efficiency,it is to soft and resiliant.Find an adhesive that cures harder,5200 is great for caulk but it's not hard enough.In most yards I worked in they either used an epoxy or a through-the-hull fairing block.

[Marcus]

What Iya said, ditto. You can cut a piece of big PVC pipe at the angle to conform to your hull, 5200 it down so it's sealed, put transducer inside, fill it with your preferred medium (mineral oil works very well), then put a cap on it with a hole in the center that the shaft of the transducer pokes thru. Also use that hole to mount the transducer upright.
That would be a good professional installation. Or, you can do what my friend does and just leave it sitting in the bilge area with a little water. Works great running full speed. It has 800W RMS power though, Sitex 10" CRT.