Rickie..... Just talked to HB support, the only cable they have to support NMEA GPS output from a helix 10 (or any other HB GPS/combo unit) is the AS HHGPS cable and the document I mentioned is good for the wiring info. Basically, it's pretty simple - from the AS HHGPS cable, the black wire (-) connects to whatever color the NMEA ground (-) wire is on the unit you are sending GPS info too (in my case, a GX1600 VHF, green wire), and the AS HHGPS white wire (+) to the NMEA GPS input (+, blue wire on the 1600). When I receive my 10si and wire it up, I'll let u know......