Lowrance Problem

[Elton]

Posted on behalf of Gary. Please add all replies to this thread:

 

I have a Lowrance X-91. After a depth of approximately 100 feet (salt or fresh), the sounder quits working. Anyone able to help me? I have gone through the manual, but I can't get it to show the bottom. Any suggestions?

Thanks,

Gary

[Stoaty]

Have you go the depth range set to 100ft? Make sure your range is on auto or set for more than 100ft.

Edited November 5, 2007 by Stoaty

[Toerag]

Sounds like a 'transducer not powerful enough' problem. What sort of transducer is it, and how is it attached to the boat? How many watts (RMS) is the transducer? My old X71 would run out of puff at about 80m, my x88 has a more powerful transducer and is good for over 120m.

If it's not a transducer power issue, then you have a setting wrong. Fix the upper and lower limits to, say, 80 & 120ft. Make sure you can see the bottom at 80m or so, then slowly drive into deeper water and see if it stops at the 100ft mark. Turn off 'fish ID' and any sort of 'noise reduction' settings. If it's a dual-frequency job then try a different frequency, lower frequencies go deeper, but 200khz is what most sounders run at, and that's good for 120m if the transducer has the power.

PS. you should set your depth readings to be in metres like your charts, it saves doing metres<->feet conversions in your head all the time.

[Stoaty]

you should set your depth readings to be in metres like your charts, it saves doing metres<->feet conversions in your head all the time.

 

Your right of course, but the government sent me to a grammer school where I spent my childhood working in feet and inches. I can visualise feet. I am happier doing the sums in my head.

[Fastd]

There is a good link on Lowrance units here and how to set them up.

 

http://www.lowrance.com.au/__data/page/8/L...s_Sept_2002.pdf

 

If you look at that on page four it mentions the x91 as being capable of depths of 200 metres so it should be fine in 100 ft.

 

You will loose sensitivity in having a shoot thru hull transducer. On my old lowrance unit (which was low powered and shoot thru hull) I had a similar problem.

 

Try turning off the auto sensitivity as it can sometimes be too failsafe. Also check your transducer is mounted to send a signal vertically with the boat loaded and ready to fish. If it sends at an angle some of the returning signal can be lost.

 

I have to admit to fixing my problem by replacing it with an eagle df480... a far more modern and powerfull unit.

 

Cheers

Dave

[Toerag]

Stoaty - I have 2 sounders, one in metres, one in feet - Although I was brought up on metric measurements I use the imperial one when I'm feathering, and the metric one when looking at the bottom. Fishing has allowed me to convert pretty easily between the two.

FastD has very good advice too.

[Fastd]

Thing I forgot.

 

If you use a shoot thru hull transducer make sure you dont have a dual skin boat. The emissions from the transducer will pass thru solid mater...ie a hull /water oil etc ...but not thru air...its how they work by sensing the swim bladders of fish.

 

If you have a boat with a dual skin that incorporates an unsinkable polystyrene membrane this will seriously reduce the efficiency of the sounder if not totally stop it working.

 

Occasionally you can choose a mounting on solid fibreglass that has air bubbles in it...this will affect sensitivity. One way round this is to choose a place to mount the transducer and build a dam off plastercine round it...fill the dam with oil or more enviromentally friendly anti freeze. Teporarily mount the transducer and see what results you get...you could flood the bilge teporarily for the tests. Move the transducer till you get good results.

 

I only use an external transducer to negate any hull send thru problems but make sure it is mounted outside the engine or hull turbulance. Bubbles in the wake affecting the transducer will afect is sensitivity

 

Cheers

Dave