transducer in 38
#11
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Originally posted by G.HAVERDINK
HERE'S THE ANSWER:
Does a depth finder need to work over say 15-20 MPH ? If you're running faster than that in a suspect shallow water area you are asking for punishment. If you're running faster than 20 MPH - who cares what the water depth is!
HERE'S THE ANSWER:
Does a depth finder need to work over say 15-20 MPH ? If you're running faster than that in a suspect shallow water area you are asking for punishment. If you're running faster than 20 MPH - who cares what the water depth is!
#15
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Tried a few more locations in the back of the boat this weekend, including on a flat spot directly in front of the drain plugs underneath the stringer in the center of the boat. There is no question you cannot mount a transducer in the back of a 38 stepped hull Avenger and have it read when on plane. It is hard to believe that the water is turbulent enough there when barely on plane to keep it from reading, being as far as it is from the last step, but as soon as the boat rolls over the depth finder loses the bottom. The factory unit must be in front of the first step. When I next bring it home I will install an access panel in the small wall under the step into the cabin and see if I can mount the new transducer there and somehow snake the cable up under the dash. Anyone ever work on this area of the boat? any tips on the best direction to go with the cable?
Robert
PS.
Haverdink - Pull up a detailed chart of any bay on the gulf coast. Look at the bottom contours - channel widths- distance between markers, etc, and then factor in tides, weather, and a shifting sandy bottom that makes it, like all bays, sometimes unpredictable. Pick Mobile Bay as an example. Note that I said shallow bays, not small ones in my prior post. I don't know what it is like to boat on the great lakes, but on the coast, the bottom can change significantly in a matter of hours.
In my post I stated "maybe it doesn't do any good but to make me feel better, but I like to see the trend on the bottom in the direction I'm heading when on plane." I don't really know if my keeping an eye on the depth finder is a factor or not, but I do know that in 20+ years of boating both inland and at the coast I have never once dinged a prop, hit a sandbar, or had any other incident. I also know that I didn't buy an 80+ MPH OFFSHORE PERFORMANCE BOAT to idle in, and you have to drive it through a bay to get it offshore.
Robert
PS.
Haverdink - Pull up a detailed chart of any bay on the gulf coast. Look at the bottom contours - channel widths- distance between markers, etc, and then factor in tides, weather, and a shifting sandy bottom that makes it, like all bays, sometimes unpredictable. Pick Mobile Bay as an example. Note that I said shallow bays, not small ones in my prior post. I don't know what it is like to boat on the great lakes, but on the coast, the bottom can change significantly in a matter of hours.
In my post I stated "maybe it doesn't do any good but to make me feel better, but I like to see the trend on the bottom in the direction I'm heading when on plane." I don't really know if my keeping an eye on the depth finder is a factor or not, but I do know that in 20+ years of boating both inland and at the coast I have never once dinged a prop, hit a sandbar, or had any other incident. I also know that I didn't buy an 80+ MPH OFFSHORE PERFORMANCE BOAT to idle in, and you have to drive it through a bay to get it offshore.
#16
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The factory mounts the transducer underneath the fridge on the port side. After removing the fridge you will need to drill a hole (i think 2 1/4" dia.) thru the balsacore. BE CAREFULL! The glass on the bottom is approx. 1/4" thick. The transducer will "shoot" thru glass, but not balsa or any other obstruction. Are you using the recommended epoxy to mount the transducer with?
#19
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The previous images come from http://home.infi.net/~brip/index.html
Keep in mind that these are images of a 340 and I have a 380. In the bilge area, I first tried position 1 (under the back seat) then position two under the front of the engine. I was using lowrance's epoxy. I would guess that both times I was shooting through the coring, as the bottom was significantly thicker in those places (about four inches away from the center stringer) then it was in 3, the notch directly under the stringer, which appeared to be pure fiberglass. Since the transducer worked fine at rest, idle, and up until the boat rolled over on plane (approx 20MPH) with no extraneous noise, I assume that I will be ok shooting through the coring (I don't care about running at any significant speed with the depth finder, If I could just use it while on plane I'll be happy). It could be bad judgement on my part not cutting through the coring, but it sure seems like there is no coring at 3 and it still wouldn't work, plus I hated to cut holes halfway though the boat while experimenting.
I had thought to try next under the cockpit in picture two, position 4 - next to the shower sump (which I assume is in front of the first step in the 38, but if it is not I'll have to regroup)
Haverdink (Greg?), thanks for that info. Are you saying that the factory transducer is around position 5, over on the side of the hull, and not in the center? Any thoughts on the best way to route the transducer cable to either there or position 4?
Keep in mind that these are images of a 340 and I have a 380. In the bilge area, I first tried position 1 (under the back seat) then position two under the front of the engine. I was using lowrance's epoxy. I would guess that both times I was shooting through the coring, as the bottom was significantly thicker in those places (about four inches away from the center stringer) then it was in 3, the notch directly under the stringer, which appeared to be pure fiberglass. Since the transducer worked fine at rest, idle, and up until the boat rolled over on plane (approx 20MPH) with no extraneous noise, I assume that I will be ok shooting through the coring (I don't care about running at any significant speed with the depth finder, If I could just use it while on plane I'll be happy). It could be bad judgement on my part not cutting through the coring, but it sure seems like there is no coring at 3 and it still wouldn't work, plus I hated to cut holes halfway though the boat while experimenting.
I had thought to try next under the cockpit in picture two, position 4 - next to the shower sump (which I assume is in front of the first step in the 38, but if it is not I'll have to regroup)
Haverdink (Greg?), thanks for that info. Are you saying that the factory transducer is around position 5, over on the side of the hull, and not in the center? Any thoughts on the best way to route the transducer cable to either there or position 4?
#20
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Yippee! It works!
Today I pulled the fridge, cut an access hole in the panel under it, and found the factory transducer right where G Haverdink said. Thanks G, you saved me a lot of time and effort. Looking at the factory transducer for the LMS 3500, the top of it was almost flush with the inside of the hull, so the hull must be very thick there. I didn't want to risk cutting through the top layer of fiberglass and the coring, so I tried the old look at the depth finder while holding the transducer against the floor in a baggie full of water trick. After tweaking the depth finders sensitivity, grey level, and other settings, I found a place where it would read great while sitting still. In my boat it was directly towards the centerline of the boat from the other transducer as close to the inboard stringer as possible (about 4 inches towards the centerline from the other transducer). I cleaned it, epoxied it down, waited about 15 minutes, and took it for a test drive. It read good up to 65 MPH as long as I didn't trim the bow too far out of the water. I am very happy with the results.
To run the transducer cable back to the dash, I snaked it from the fridge area down the gunnel, across the boat through the back seat, and up the other gunnel to the dash. This is an easy two person job. I had to use the 12' transducer extension for it to reach.
The unit I mounted was a lowrance lms-320 GPS/sounder. I used the 200Hz thru-hull transducer. Note that it is not likely to work if the LMS-3500 (192Hz) is turned on, I wired both units to two of the extra accessory switches in the dash so I can run either if desired. I really like this unit, the difference in resolution from the LMS-240 in my last boat is amazing. Plus the new MAPCREATE maps are vastly improved as well.
For mounting, I placed the unit on a RAM mount that I attached to the dash plate that hold the tachs and speedos. This lets me position the unit optimally whether I am standing or sitting. I will attach pictures next time I am at the boat with my camera.
I hope this helps anyone else that would like to have a depth finder at greater then idle speeds. Note to all 380 owners, It is a good 5 feet or so from this transducer location to the bottom of the props at idle.
Again, G Haverdink, thanks for your help.
Today I pulled the fridge, cut an access hole in the panel under it, and found the factory transducer right where G Haverdink said. Thanks G, you saved me a lot of time and effort. Looking at the factory transducer for the LMS 3500, the top of it was almost flush with the inside of the hull, so the hull must be very thick there. I didn't want to risk cutting through the top layer of fiberglass and the coring, so I tried the old look at the depth finder while holding the transducer against the floor in a baggie full of water trick. After tweaking the depth finders sensitivity, grey level, and other settings, I found a place where it would read great while sitting still. In my boat it was directly towards the centerline of the boat from the other transducer as close to the inboard stringer as possible (about 4 inches towards the centerline from the other transducer). I cleaned it, epoxied it down, waited about 15 minutes, and took it for a test drive. It read good up to 65 MPH as long as I didn't trim the bow too far out of the water. I am very happy with the results.
To run the transducer cable back to the dash, I snaked it from the fridge area down the gunnel, across the boat through the back seat, and up the other gunnel to the dash. This is an easy two person job. I had to use the 12' transducer extension for it to reach.
The unit I mounted was a lowrance lms-320 GPS/sounder. I used the 200Hz thru-hull transducer. Note that it is not likely to work if the LMS-3500 (192Hz) is turned on, I wired both units to two of the extra accessory switches in the dash so I can run either if desired. I really like this unit, the difference in resolution from the LMS-240 in my last boat is amazing. Plus the new MAPCREATE maps are vastly improved as well.
For mounting, I placed the unit on a RAM mount that I attached to the dash plate that hold the tachs and speedos. This lets me position the unit optimally whether I am standing or sitting. I will attach pictures next time I am at the boat with my camera.
I hope this helps anyone else that would like to have a depth finder at greater then idle speeds. Note to all 380 owners, It is a good 5 feet or so from this transducer location to the bottom of the props at idle.
Again, G Haverdink, thanks for your help.




