Fishing Eddie
09-08-2001, 09:29 PM
Why is that all fish finders show on the simulation or instru.booklet the perfect little upside down v if you will for fish and on the water you just get marks, lines but never the upside down v. I've been in alot of boats and they too show just a line or a mark. By the way I have a bottom line. Any suggestions would be helpful.
ampersat
09-08-2001, 09:53 PM
i believe what you're referring to is the gain setting on the finder. it's sort of like the squelch function on a radio or CB. you can adjust the gain to any sensitivity you like, taking out extraneous details if you want. i was reading an article a while back out adjusting it so that you can see the ball on your downrigger so that you know exactly what depth you're fishing in relation to the fish.
Trout,myster
09-09-2001, 05:58 AM
FE- Getting the arches to show up on your depthfinder depends on a)where the fish is in the "cone", b) how big the fish is and c) pixel count of your display. The gain has some effect as Ampersat mentioned, but only to the detail of what you see.
You have a Bottomline, and if it's an upper-end model (like a Tournament) you have plenty of "pixel power". The higher the count of vertical pixels (horizontal usually aren't low on counts) the better the picture just like TV! Pixels are the little lights in your screen.
Next, there is the cone. The majority of depthfinders run about a 20 degree transducer. What you see on your screen is an area about 1/3 the depth of water you're in. You have to envision a cone starting from your transducer and spreading out on the bottom of the river. In 30 feet of water, you get about 10 feet of coverage.
The arches appear as a fish travels through the cone. When the fish enters the edge of the cone, pixels are lit up. As it moves further through the cone (assuming the center of the cone), more pixels are lit higher on the screen indicating a stronger echo or signal. As the fish passes on through, the signals get weaker and the pixel line heads back down. What you see is an arch.
Many of the fish are either small or just catch the edge of the cone. If they catch the edge, they just produce a "blip" on the screen, or the line you refer to. In 10 feet of water, for example, you will be lucky to see an arch as you're looking at a 3 foot diameter circle on the bottom. At 6 feet deep, it's only about 1 1/2 feet in diameter. Chances of a whole fish going through that are small.
I'd recommend you get out in deep water like 50 to 100 feet. Turn off the garbage (fish ID, auto mode) and crank you gain up until the screen turns black, then back off until the clutter thins out. If there are fish around (sturgeon are good ones) you should see arches provided you have the pixel count to do so.
Hope this helps. And don't get the idea I'm an expert on these things, I just ran across a couple of good articles that explained it well.
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