Re: Can I ground my loran to the I/O?
You will have 2 grounds on your LORAN and maybe 3. Each has a different job to do and each is important.<br /><br />The first ground is the power ground, the negative side of your DC circuit. It won't hurt anything to ground this to your engine but you'd be better off to buffer that with the battery. So if you have a negative side buss bar that is connected directly to one of the battery's negative side cables go ahead and connect this one to the buss bar.<br /><br />The second one, and this is the one you are probably talking about, is there to establish a ground plane for the antenna. LORAN uses relatively low frequency broadcasts for its operation and as a consequency the actually antenna is very long (although your antenna itself is quite short there is a wire inside the coupler that is part of the antenna and that wire is hundreds of feet long). For your antenna to work properly that antenna wire has to be complimented by a ground plane, which the water would be happy to provide if you give it a way to do it. So that second ground connects the water to the antenna system (by way of the display unit usually) and it is essential to proper operation of the LORAN. This one definitly should NOT be connected directly to your engine. There is a very good possibility that you have all sorts of electrical eddys passing through that engine, some from spark plugs, some from plug wires, some from alternators, some from goodness only knows what. The very last thing you want to do is make a direct connection between all of that electrial mess and your antenna. See what I mean? This line should be connected directly to an earth (water) ground. It was no accident that Marinco used to sell an awful lot of "Dynaplates" for just this purpose. They work, buy the smallest one they make (hint - buy it on E-Bay where they sell for about a fourth of what they do elsewhere) and hook it up. <br /><br />Oh, the third ground, if you have one (most LORANs don't), is a chassis ground which is just there to bring the potential down to zero. Connect it to the dynaplate too, if you have one.<br /><br />Thom
