NMEA 2000 Power Question

[Bill Reynolds]

I have been under the impression that the N2K network had to have a 120 ohm resistor at each end of the backbone. I thought my network had a Resistor at the end of the backbone extension cable running to the bilge. I was rearranging some wiring and discovered that the extension cable was hooked directly to my Point-1 without a resistor. I added a tee and resistor to the cable so it is Hooked up properly now but I am confused as to why it was working before.
Can you Guys shed some light on this?

Also, do you think Lowrance will come out with a Bluetooth Point-1?

[NoCAL]

NMEA is an enigma. To work properly, it should be configured as you describe. It’s very possible you have a full network under your dash with 2 terminators and the extension cable is coming out the bottom of a T from there and then connecting to the Point 1. Having said all that, some people get the thing to work with some odd setups. To be safe, it’s a good idea to follow the industry standards as it sounds like you now have.

NoCAL

[Bill Reynolds]

In retrospect, I have had problems with directional accuracy and have had to recalibrate several times. I could see the group of tees under the dash with a resistor on one end and extension cable on the other. The extension cable connected to the Point-1 inside the rigging tube running to the transom so I could not see if a resistor was there. I did wonder how they got a tee and resistor inside the packed tube, well they didn’t.
In the process of diagnosing the network, I ran across this document. It was helpful so I am passing it on.