Originally Posted by Dockhead
And I agree. I don't know why they call it a "signal ground" -- the phrase seems nonsensical to me. But NMEA0183 v1.0 et seq but before 2.0 had common negatives which could be wired together.
Maybe that's Rustic's problem?
Yes, I have worked it out, no thanks to Raymarine
tech guys. In the manual it's called a Ground (drain) wire. Now, whilst it doesn't say to connect it and the black negative cable together, that's what I've done and it's working fine. It does say,
"the power cable supplied with this product includes a dedicated shield (drain) wire for connection to a vessels RF Ground point", that's the thin black wire I was talking about. It goes on to say,
"It is important that an effective RF ground is connected to the system. A single
ground point should be used for all equipment
. The unit can be grounded by connecting the shield (drain) wire of the power cable to the vessel's RF ground Point. On Vessels without an RF Ground system the shield (drain) wire should be connected directly to the negativie battery
terminal" which is what I have done.
I'm really not familiar with the RF ground system at all.