Author Topic: losing 2D sonar @ speeds >15 mph (Read 11733 times)

jclark · « **on:** March 07, 2010, 01:31:23 PM »

new to forum and need help. i have a 997 csi, and i have been losing 2D sonar @ speeds > 15 mph since the day i bought the unit (oct 09). sent pics of first mount (after adjusting pitch and height numerous times to no avail) to joby @ humminbird. suggested a new location. tried that, again over and over with no change. even put an in- haul transducer (what a pain) and it was a little worse on the in-haul. the si/di work fine but lose return >15 on 2D. i fish tampa bay (primarely flats) but it would be nice to know when runnig over deeper water, of holes and depressions, to fish on. could it be the machine or the transducer. have read on a couple of forums of simalar problems. never had this problem with my older (non- humminbird) unit. help please.

RGecy · « **Reply #1 on:** March 07, 2010, 04:45:08 PM »

jc,

It would be very helpfull if you could post some pictures of your install showing transducer location. Multiple views would be good from side, straight on, shots of the transom, etc!

Good Luck,

Robert

sonar2000 · « **Reply #2 on:** March 07, 2010, 04:51:54 PM »

Yes. pictures please. I am starting to think there are issues with location with respect to plane speeds. We are seeing too much poasts on this. It seems we may need to have a servo motor for tilting the transducer. Chuck

jclark · « **Reply #3 on:** March 08, 2010, 08:37:52 AM »

Trans Ducer Photos.pdf (1117.2 kB - downloaded 349 times.) here are the originals photos of the transducer mount. the pic with the red X on the transom is where i was asked to relocate. it was no better,so i moved it back to original spot . i have since lowered the back end of the transducer a lot (after reading info on the forum) but have not been able to get out - florida weather go figure. any help or ideas would be greatly appreciated. thanks

sonar2000 · « **Reply #4 on:** March 08, 2010, 10:04:39 AM »

You can post the pictures in this forum and within the post topic as well. when you pull up the topic and reply there is an area at the bottom called attach. to the right is a browse button click on the browse and within your computer find the picture and then open the picture. when you post the reply it will put your picture in the post. chuck

RGecy · « **Reply #5 on:** March 08, 2010, 10:40:06 AM »

I think you are getting air coming under that outside step. There also looks to be another step further up in front of the transducer that could be causing turbulence.

I have a very similar hull design and mounted mine on the step where the hull rest on the bunk or just inside it so you dont knock it off if your boat pulls up too far on the trailer.

Robert

jclark · « **Reply #6 on:** March 08, 2010, 11:34:00 AM »

robert, are you talking about the step right above the board with the reflector on it.

Jolly Roger · « **Reply #7 on:** March 08, 2010, 02:04:11 PM »

I think Robert is right.
In my opinion the transducer is too far out to the side and gets air underneath.
Air bubbles will go up and the transducer sits at the highest place possible at the moment. I'd rather go to the X-marked spot and try to mount it there with the same angle like you have mounted it at the moment.

Regards / Harry

jclark · « **Reply #8 on:** March 08, 2010, 02:51:46 PM »

That's my problem harry,i did mount it at the x and the result was losing bottom at ~ 11-12 mph. Robert mentioned to mount it just to the right of the x, at the step above the board over the reflector light (am i correct robert).

Kimi · « **Reply #9 on:** March 08, 2010, 02:59:15 PM »

In my opinion the transducer is too far out to the side and gets air underneath.
Air bubbles will go up and the the transducer sits at the highest place possible at the moment. I'd rather go to X-marked spot and try to mount it there with the same angle like you have mounted it at the moment.

I agree 100%.

Some "speedboats" are also "flying" and jumppin ower the surface, so you cant expect that the transducer geting good contact whit the water in high speeds. In other words your sonar does not work in high speeds. Thats just something you have to live whit.

Kimi...

jclark · « **Reply #10 on:** March 08, 2010, 03:48:51 PM »

unfortunately this boat is far from a speed boat. it is a twin haul flats fishing boat, with tower, power pole, trolling motor and fighting chair. it's 24 foot long and 8 1/2 feet wide. .

reddog · « **Reply #11 on:** March 08, 2010, 03:51:46 PM »

I'd line up the right side of the xducer 1/4- 1/2" from the right side of the lower step with the same tilt as shown. I think there is way too much potential for interference where it is now. (centered it on the reflector) Particularly with the mid hull step shown in pics 5-7. I think that is the culprit at high speeds.

jclark · « **Reply #12 on:** March 08, 2010, 09:14:17 PM »

reddog thank you. i'll give it a try. i love the si and di but to only see the 2d at speeds less than 15 is frustrating esp running the flats.

Humminbird_Greg · « **Reply #13 on:** March 10, 2010, 12:54:04 PM »

I think that the area I circled in green from one of your pictures is the area Robert was speaking about.

You said that the inside-the-hull transducer did not give better results? Typically that would be the best place to install a transducer to get the best high-speed depth readings. You said that it is a twin hull flats boat; does that mean that it has a double layer hull with something like wood or foam as a sandwich in between layers? For an inside-the-hull transducer to work it needs to be mounted in an area that has a single layer of fiberglass of an inch or less in thickness. I have heard where some have used a forstner bit to drill through the first layer of fiberglass and mounted the inside-the-hull transducer directly to the (outside) second layer of fiberglass and had gotten good results. The same can be done for hulls thicker than 1 inch because in drilling the area for the transducer you are reducing the thickness of the hull.

With your boat having so shallow of a draft (a flats boat right?) I think that your best chance would be in getting the inside-the-hull transducer to work at high-speeds is your best option.

jclark · « **Reply #14 on:** March 10, 2010, 06:40:41 PM »

greg, i actually have 2 outside hauls (like a plantoon boat - only all glass). with the in-haul, i sanded down a bit on the inside to make sure there were no bubbles then put down resin and attached (followed instructions). that spot where the green circle is, is only a 3" lip at most. i could use any and all help on this problem though.

Humminbird_Greg · « **Reply #15 on:** March 10, 2010, 06:47:02 PM »

jclark,
Before you used the resin to install the transducer inside-the-hull did you test the location first to see if it would work?
Does your boat have a single layer of fiberglass less than 1 inch thick?

jclark · « **Reply #16 on:** March 10, 2010, 08:23:16 PM »

i tried it in 4 locations and the one i put it in was the best. yep my haul is 1 layer, less than an inch thick.

Humminbird_Greg · « **Reply #17 on:** March 16, 2010, 09:43:49 AM »

I am assuming here that during testing that it would read above 15 mph. If the transducer worked differently between the testing and final installation than it has to be due to the epoxy used, the epoxy not curing all the way, the transducer being disturbed or shifting while the epoxy was curing, or you got air bubbles under the transducer. Make sure that the boat hull and air temperature is high enough for the epoxy. Fully mix the epoxy but do so without introducing any air bubbles. When you install the transducer press down and twist it so as to force out any unneeded epoxy and air bubbles. Place a weight on top of the transducer so it remains against the hull and does not move while letting the epoxy fully cure.

jclark · « **Reply #18 on:** March 16, 2010, 09:42:12 PM »

i picked the spot for the inhaul where i got the best reading for speed. then i epoxied hoping it would be better. it did not. i have moved transmount the transducer to thhe spot where the board (above the reflector) is. going to try tomorrow. hope it works.

garyr · « **Reply #19 on:** March 17, 2010, 08:48:10 PM »

I sympathise with you.
I had the same problem.
You have several dilemma's.
1. Do you allow your ducer to stand out like a sore thumb? Do you allow the chance of busting it off to allow 2d returns at speeds greater than 10 mph? I damaged the ducer installed this way, $200 and someodd is a chunk of change. I did not want to damage another.
2. Do you install in a safe zone away from submerged object on the transom not where the boat planes? Behind the area of the jack plate. This will allow si at speeds less than 6 mph? No 2d returns at planing speeds.
3. Compromise? This is what I did. My transom was beginning to look like Swiss Cheese with the drill holes. I decided to install a high speed ducer xnt 9 20 t that was supplied with the 1197. I purchased the advanced system side imaging y cable. This setup is interphased with the 180 ducer and high speed ducer. The unit switches automatically to the si ducer when the speed is less than 10 mph, to high speed when speed is greater than 10 mph. I reasoned you lose si at speed greater than 6 mph!
I have named my boat "Swiss Cheese."

jclark · « **Reply #20 on:** March 21, 2010, 06:22:03 PM »

Went out this weekend with transducer in third location (above board with reflector). Still lose 2D sonar>14 mph. Si and Di work great. Other 2 locations I raised and lowered backend of transducer as well as moved whole unit up and down. To no avail. Like I said before even installed an inhaul (single glass layer, <1 inch) no good. Need help and advice, Could it be the haul shape(which is not good), transducer or main unit .

Jolly Roger · « **Reply #21 on:** March 21, 2010, 07:50:10 PM »

jclark,
just to figure out what might be wrong there besides the transducer location: Can you swap your head unit with someone else?
If your unit shows the same symptoms on another boat there's propably something wrong with it.

My 2 cents
Harry

jclark · « **Reply #22 on:** March 23, 2010, 06:01:20 AM »

i will asked around. hope that is the problem. hate to think it is haul configuration. should i lower transducer way down in hopes i can get below air bubbles if that is the problem.

Humminbird_Greg · « **Reply #23 on:** March 23, 2010, 09:21:30 AM »

You can try that but there are no guarantees on the results.

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