Chandrella wrote in
:

Question is, can I just common the NEMA IN/OUT data cables at both
stations between the gps and vhf? That is, simply plug the gps into
whichever location I want to use it at, by hooking the data cables
together in parallel. Of course only the 1 gps would be hooked to the
one vhf radio at whichever gps station. My concern is impedence or
stray signals possibly from the unterminated data cable.

Wold be using these data cables from Garmin. Run would only be about
10 feet between the cabin and helm station.


NO! Never connect NMEA out and in together on any device. NMEA is a
queer beast. There can be only ONE talker on a circuit...one device
sending out data to up to 16 listener devices. So, GPS NMEA OUT goes to
VHF NMEA IN on one pair of wires and GPS NMEA IN goes to VHF NMEA OUT on
a separate pair of wires. (Actually NMEA - is most always hooked to
ground by some stupid company or other, but use a wire pair, anyways.

I use FOIL SHIELDED cable for all NMEA data cables wherever possible. It
keeps the radiation down that tears up the radios. Ground the shield to
the RADIO ground ONLY. It's called a Faraday Shield because Michael
Faraday invented it long ago. Leave the shield connected to nothing and
insulated from everything on the GPS end of the cable. Do not use the
shield for connections to NMEA DATA - leads, which makes it just another
noise antenna.

Good cable to use for this installation is available at computer shops.
It's call CAT-5 shielded cable used for Ethernet networking. It has more
than 4 conductors. Just cut off the ones you're not using short, NOT
wrapped up around the outside to form another noise antenna from inside
the shielding, please. Keep all those unshielded wires on the GPS and
radio as short as is practical to reduce their radiation.



Larry
--
VIRUS ALERT! VISTA has been released!
NOONE will be spared!