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Simulator mode on 582L fishfinder

Old 12-26-2003, 06:05 PM
  #1  
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Join Date: Dec 2003
Location: Long Beach, CA
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Default Simulator mode on 582L fishfinder

I'm a newbie on this board. I fish out of Long Beach Calif. on my 22' Marlin. I figured I'd start right off with a stupid question. Should I disconnect the transducer cable on my Furuno when I run it in simulator mode in the driveway? The manual is a little unclear. I'm not sure what I'm nervous about. Seems like it might not like that concrete hard bottom at 2'.

Joe
22' Marlin
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Old 12-27-2003, 08:10 AM
  #2  
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Default Simulator mode on 582L fishfinder

Joe,

There is no reason to disconnect your transducer when you run the fish finder in simulator mode, so you're OK there.

Here is an allusion for you. If your boat is on the trailer, parked in your driveway, and you are out there and flip on the bottom box it will probably show something on the screen that you think may be the driveway at about 2 feet. It won't really looke like bottom would in shallow water but you'll be pretty sure its the driveway. Its not. Sorry.

Others that know a lot more about this than I do may chime in but I beleive what you are seeing is a direct result of the ringing you sometimes hear mentined within a transducer. It also occurs to me, and I do not know if this is relevent or not, that what you see at an indicated depth of about 2 feet also seems to correspond to about the minimum depth the machine is able to measure. Might be a coincidence, might not, I do not know.

Let me try a layman's explaination on the \"Ring\" with an annology that just occured to me that might make some sense.

We all sort of know intuitevely that you can not speak and hear at the same time, which is suprising when you consider that we use two different sensing devices for the processes. Anyway our transducers are like that, they have to shut off their listening-for-return-echos ability while they ping. The ping the transducer makes sounds like a distinch click but in fact on its back side there is a little ringing sound, just like you'd get if you smacked a Gong, that continues for a bit after the transducer is 'struck' by it's own particular bolt of lightening (the power applied by the display unit). That continued ringing, when power is not being applied to the transucer, will be recognized by the display unit as a return echo and display it. The lenght of time that ringing lasts will be displayed as surface clutter because the display unit has no way to distinguish between a real return echo and a ringing so it splashes some color on the screen. I think it is that band of color (well, maybe grayscale) that is often mistaken for having read the pavement when the boat is on the trailer, just because the displayed band happens to be roughly the same width as the distance from the transducer to the ground.

Conversly, if I'm understanding this stuff correctly, any return echo will also be accompanied by a bit of ringing of the transducer's element. Obviously it will be much much more faint a ringing than the ringing that was caused by the outgoing ping's surge of electricity, but it will still be there on the incomming side. I think that this return echo ringing is what haves the effect of making targets look a little fuzzy and blurs the distinction between closly spaced targets. At least to me it seems that this would have to be the effect. This is what I think I've been reading, but once again, could be right, could be wrong, 50/50 chance.

Here's my silly little analogy. You can go out and shoot a rifle while in a canyon and if you are sort of curious you can estimate the distance from you to the canyon's far wall by timeing the interval between when you shoot the gun and when you hear the echo of its report. What's the speed of sound in air, something like twelve hundred feet per second or something like that? So it it takes three seconds the sound traveled 3,600 feet, but that includes the trip out and the trip back, so the canyon wall sould be about 1,800 feet away. Not to tough to figure out. The thing is that when you pull the trigger (equal to the display unit emmitting a pulse of electricity) mechanisms will be put into effect that will cause the rapid burning of the powder and expulsion of the projectile from the barrel and a resulting BANG. If the canyon wall was only a few hundred feet away from you you would not be able to measure the time interval between the bang and the echo no matter how fast your reflexes becasue you're hears would still be ringing so badly that you couldn't hear anything. It take a moment for the ringing to go away and your hearing to return to normal so that you can detect the return echo from the canyon wall. This is my silly little anology.

Thom

A Wise Man Once Said: \"That's EXACTLY why I try NOT to read manuals, I start trying all sorts of stupid things and wasting all sorts of time when I read manuals....\"

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