Problems with depth sounder

[twogone]

My sister gave me a Humminbird 200DX Dual Beam depth sounder/fish finder for Christmas 2 years ago and last winter I mounted it in my boat. I followed all the installation insructions as carefully as possible and half of the time it works like a dream. The rest of the time, especially in deep water, it sucks! It says I'm in 2ft of water when I know I'm in 400-600ft. (according to the GPS charts). The screen goes mostly black, it sticks on 1 or 2 or 3ft and records no fish for hours sometimes and then suddenly it will work properly for a while and then, just a suddenly, revert back to BS.
My initial thought is a faulty connection some where. It would almost have to be at the mount because I didn't shorten the stock cable from the transducer (just coiled it up with a zip tie and stuffed it up under the dashboard).
This is most frustrating because I'm told the 200DX is a pretty good unit.
Does anybody have any suggestions?
Cheers; twogone

 

[Hali killer]

Change your settings from auto to manual. Then you can set the depth range yourself. From there you can adjust your gain

 

[Seafever]

I'm not familiar with that particular model....

But on my fishfinder when I get over 300 feet deep I have to:-

access the menu panel and switch from 200mhz to 83 mhz. The lower mhz setting works better in deep water.
set the depth allocation to deeper than where I am fishing ( if the bottom is 300ft I set it to 400ft etc etc.)
go to slower "ping" speed sometimes.....
set the "sensitivity" to around 86%

If the unit's "auto sensitivity" is turned on....that will usually screw things up because the auto function always sets it too high. So turn your "auto sensitivity" off at all times and go manual about 86 to 88% mostly.

After doing this on my Lowrance I've had very good results.

Hopefully your transducer is in a location on the stern that is unnaffected by turbulence from prop or chines or ribs on boat. You only need to have it so that half the transducer is below the back bottom edge of your transom....any higher or lower could create issues.....

 

[twogone]

Thanks for the suggestions folks. I will try them out. The transducer is (according to the installation instructions) 1/4" below the transom and angled forward ever so slightly. I will take a photo of it and post that later today. That could be the source of the problem. It's over 15" from the prop (as reccommended) and most of the time works well at high speed so I'm thinking that turbulance isn't involved. The problem occurs mostly while trolling in deep water so the sensitivity & depth range adjustments may be the 'fix'. Thanks again for the suggestions, Cheers; twogone.

 

[lazoman]

Might need to angle more towards the bow

 

[cheech]

Humminbirds are pretty much junk on the chuck. That said... I believe the 200 will only go to 600' prolly less in salt. Try using the zoom feature in manual mode. That way you can 'see' the zone where your riggers should be. gl

 

[trendsetter]

I have a hummingbird 560 and I had the same issues as you when I first installed it. On mine there is a setting when you scroll down under sonar for "water type". This should be set to "salt water - deep" for the chuck. Also if you change the depth range from auto to manual and set max depth around 800' it should pick up bottom. Mine is good on these settings to about 800'. No matter what I do I can't get it to read much over that.

 

[twogone]

Here are the photos of the transducer. We made a little bracket to avoid drilling holes in the transom. the bracket has a bottom on it that is perfectly flush with the bottom of the boat except for one tiny crack which I could fill with something and grind it smooth. The is still some adjustment left on the mount so I could drop it down a bit and as per one suggestion, angle it forward a littl more.

 

[twogone]

I have just realized something; I don't ever see my cannon balls on this depth sounder. Does that mean the angle of the transducer is incorrect? It should pick them up right? Cheers; Twogone

 

[scott craven]

I have just realized something; I don't ever see my cannon balls on this depth sounder. Does that mean the angle of the transducer is incorrect? It should pick them up right? Cheers; Twogone

I run the same unit and i don't see the cannon balls either.
after fine tuning though, i can read bottom running at 20knots
the only time it loses signal is over 400 '

 

[Seafever]

TwoGone.. I never see my cannonballs on the sounder...no matter what it's set at.

Does yours have a "Surface clutter" option on the menu? This might help.

I never use "zoom"...it's just one more pain in the butt you have to deal with.

I usually tend to go with the "fish symbol" setting instead of graphic arch display......I know that symbols don't always equate with fish i.d........but whatever's down there I'll see it.

I think the auto settings like " deep water" and "slow troll" and "shallow water" simply automatically change the Mhz and ping speed settings based on what you select.

On "ping speed" setting I usually go with "normal" but if I am in deep water and it acts up I set it to "slow".


I was told by a (***cough**) Lowrance expert that I should use 83Mhz for shallow water and 200Mhz for deep water.
Even though in the Lowrance manual it says the exact opposite.

Every dual beam sounder I ever owned:- the 200Mhz in shallow and 83Mhz for deep ALWAYS worked best.....

First thing I would do, as I mentioned already, is manually set the "sensitivity" to about 87%.
This minor adjustment can work wonders.....


The "depth rating" that is printed on the carton for sounders is usually quite a bit less in coastal saltwater than fresh.

The higher the wattage rating and power for the unit, the better off you are generally........

 

[twogone]

Hi Seafever; thanks for all your sound advice (sorry about the pun). I have printed off the 2 pages of this thread and will take the prints with me the next time I'm on the water (which I hope is very soon). I think the unit I have is probably not the best for deep salt water; a number of folks have told me that Humminbirds work better in the fresh and under 300' of water. Maybe I'll get a better unit in a few years; right now I'm scratching to find funds for fuel so I'd get shot if I even mentioned a new depth sounder. Hopefully all the tips & ideas I've been given here will improve the performance of the 200DX. Thanks to all, Cheers; Twogone

 

[Seafever]

Cheers.....

I think the units that are 200 watt are about bare minimum for the chuck.

If you get one that is rated for 600ft....you can probably figure on about 300ft actual in the chuck

One I have is rated for 1500ft.....but I'm lucky to get 900ft in reality.

For awhile I used one that was good to about 300ft.......I figured that was all I needed because I only needed to know where the bottom was up to about 240ft......if I was fishing way deeper than that I would not be "bottom bouncing"...I'd be setting the tackle at 90 to 160ft regardless.

But the deeper the finder will read, the more confidence it gives as to knowing what and where.....

 

[twogone]

The specs on the 200DX is 250 Watts (RMS) and 2000 Watts (peak to peak) and it has a manual depth range of 600' but like you say, in reality that's a manufacturers exaggeration that may only be possible in perfect conditions and in fresh water. I will just have to live with it as the bucks aren't available just now for a new one and it does work well in 400' of water (sometimes 500'). It's a damn sight better than nothing. Sometimes I just have to shake my head and say to myself...man, you live in the very best part of the whole bloody world, you've got fishies to chase, catch & eat and a beautiful little boat; what more can one ask for? We aren't in Afganistan where it's mostly hot & dry and with crazies trying to blow you up. nuf said!
Thanks for your help; hope to see you on the water some day. By the way, what VHF channel do most sporties use for chit chat & fishing tips?
Cheers; Twogone