Re: Furuno LS4100 ??any good ??
I'm sorry it took so long to get to this. I managed to take the weedeater into two different Yellow Jacket nests in 3 days and the swelling hasn't quite gone down just yet.<br /><br />The ground you guys see on the back of the box is the chassis ground. Think of it as a static ground that will equalize any static that accumulates in the transducer's cable's shielding. It is sometimes called the 'static drain' in some old manuals I've see (poor translations from Japaneese mostly). One of the pins in the transducer's plug connects the shielding of the transducer and its cable to the chassis of the fish finder. If you hook it up, and there is usually no reason to hook it up, it should go to a ground to water but preferably not to the engine which is untimately always grounded to water via the prop, shaft, greartrain and so on. By ground to water I mean a metal seacock, thru-hull fitting, or if your boat has one the grounding strap or Dynaplate.<br /><br />At any rate you rarely see a boat that needs to have it hooked up at all. I don't think they have any effect at all unless during installation the transducer's cable was nicked. The way to tell of course is in the automatic mode. When its in "fishing" automatic mode and probably when the boat is still on calm water at the depth where you most commonly operate is there much screen clutter? By that I mean those little flecks of light (I have been using color machines for a long time now so I was gong to say little light blue flecks) that sort of pepper the screen some times. If you do not see those or if there are just a few now and then you shouldn't worry about that ground. If you have all that 'snow' on the screen you can hook it up to see if it will help or not. Sometimes it does, but usually only when the cable's insulation was knicked down to the shielding.<br /><br />It has a second purpose too I suppose, but I don't know if this matters to you or not. Its never been a problem for me. I suppose if you lived in a very dry area where there was a lot of static in the air, and I have a hard time immagining where this might happen over water, in which a potential woulc build up in the fish finder's case you'd want to hook it up. Maybe somewhere in the western high lakes in the fall. Maybe on the Snake or the western Columbia Rivers, one of those big lakes in Montana, Wyoming, Idaho, Utah, somewhere like that, you might be interested in hooking it up even if there was no on-screen snow.<br /><br />That help?<br /><br />Thom