On Jul 4, 9:30 pm, joseph wrote:
On Jun 29, 3:57 pm, GeoffSchultz
wrote:





I have a RayMarine SeaTalk based RayStar 120 GPS antenna which is a
piece of crap. On almost a daily basis it will lose position fix and
the requires power cycling to have it re-aquire a fix. According to
some marine electronics people that I've talked to, this was a known
problem with some of the units and is what prompted them to come out
with the RayStar 125 antenna. Since this is already the 2nd RayMarine
GPS antenna that I've purchased, I don't want to give them any more
money!

What I want to do is to mount another GPS antenna and have it feed
NMEA GPS data to the NMEA input of my RayMarina ST6001 control head.
I think that the ST6001 will convert the NMEA data into SeaTalk
sentances. The C80 chartplotter should see position data from 2
sources via SeaTalk and when the RayStar 120 antenna goes offline, I
should have no loss of position.

An alternative is to feed the NMEA data from the antenna directly to
the C80, but that involves pulling a cable to a very difficult
location.

1) Does the above solution sound like it will work? And suggestions
regarding it?

2) Any suggestions on an NMEA GPS antenna?

3) I've been looking at the Garmin GPS17 (http://www.gme.net.au/garmin/
gps17n_specifications.php) antenna and I think that it would do the
job. Any comments on this?

Thanks, Geoff (who just arrived in Deltaville, VA)

Geoff, The simplest solution is to replace the 120 with a 125. They
are the 120 replacement since the known issues with the 120. I have
not seen any failures to date with the 125 except the delicate cable
but if you make sure the cable is not damaged during installation you
should have no problem. The Garmin 17 can be connected to your
autopilot at the course computer NMEA connection. It will not directly
interface with the Seatalk connections. You will not have GPS on your
plotter from the Garmin antenna unless you connect the Garmin to the
NMEA cable on the back of your plotter as I understand it. You might
want to give Raymarine a call to verify that. Glad to hear you are
back in the States. Enjoy Deltaville. Chuck and Susan, SV Sea Trek- Hide quoted text -

- Show quoted text -

Hi Chuck,

Nice to hear from you. I've ordered the Garmin antenna and will
experiment with it.

I used to work for Digital Equipment Corp (DEC) in the engineering
department for Fault Tolerant systems where we designed systems that
had 99.999% uptime. There were no single points of failure and
everything was at least 2x redundant. To me the Garmin NMEA antenna
looks like the best solution as I can feed NMEA GPS data to my
redundant RayMarine C-80 and Northstar 3100i chartplotters. That
might sound excessive, but I've had lots of single unit failures, and
I've even had one time when both units were down. You'll note that I
even went with different vendors in case one of them had a software
problem which rendered the unit unusable. Based upon where I
typically cruise, calling tech support and just shipping the unit in
isn't a viable option. Based upon my background, I tend to worry
about things that most people don't.

-- Geoff