I am trying to connect my PC to a RayNav 300 using the NMEA input to the
Raynav.

The Raynav connector has 4 separate wires:

WHITE (+ve)
GREEN (-ve)
YELLOW (Data Out)
BROWN (Common)

Based on an (un) educated guess, I presume that I connect the WHITE wire to
pin 3 (transmit) on the PC's serial connector and the GREEN wire to pin 5
(ground)...but perhaps that is wrong???

(I am using the Yellow and Brown wires to receive NMEA from the GPS - and
that works perfectly.)

I can't find any documentation on this at the Raymarine.

Any advise will be appreciated. Larry???

claus