Electronics Wizzos

[CraigBradley]

I've recently installed a JRC 1000 radar and want to connect to our Autohelm (now Raymarine I beleive) nav system (ST50 GPS and Navdata) and if possible, the Navtex printer - to get LL on the radar screen and other useful bits of nav info.

The radar have 4 spare wires (Nav +ve; Nav -ve; Compass +ve; Compass -ve) and the back of the Navdata unit has a spare 'port'. I've bought a Raymarine D128 NMEA lead but not sure what goes where.

Thanks all

 

[alan]

I'm not familiar with either the JRC1000, nor the Navdata. However, I am pretty sure if the JRC supports NMEA then the Nav+ and Nav- are the serial data lines to be connected to an external device. I would suppose the Comp+ and Comp- are the lines to be connected to a fluxgate compass output to enable course up display on the radar.
Basically what you need to do is to get the output from your GPS (the one which also goes to the autopilot) and connect it to the Nav+ and Nav- on the radar. The NMEA interface is a serial data interface and needs the correct polarity for the signal to be decoded. Of couse you need to be sure that the JRC accepts NMEA sentences for this to work.
Hope the above helps a little - no doubt someone else will reply who has actually already hooked these instruments together.
If you have the interface specifications for the two instruments and want to fax or e-mail them to me, I'd be happy to have a look and give my opinion.

Alan Cloke
Nettuno Italy
(fax: 39-06-98600338 e-mail alcloke@tin.it)


Alan Cloke

 

[Piers]

Try calling Dave Wellcome of Raymarine (he's their autopilot and electronics genius, and always so willing to help) on 02392 693611 extension 1614.

Piers du Pré
www.playdeau.com

 

[CraigBradley]

Thanks chaps, I'll have a go and retrun if lost.
best wishes

 

[jfkal]

If all the rest of your stuff is Autohelm, then you have the Seatalk data bus which is not compatible to your radar unless on of the Autohelm units has a clearly labelled NMEA Out connector. However beware Autohelm only translates a minimal set of info into NMEA, unless you have bought the Seatalk NMEA Bridge. There you will have an NMEA Out + and - and a R232 + and -. Try to hook the NMEA OUT to the Radars NMEA in. If it does not work try the RS232 ports.
(Strangely enough only the RS232 works for me even though I have an NMEA listener. Could be something with the signal levels. Did not bother to check since the RS232 worked for me.
Note: on NMEA you can have one sender and multiple receivers but not the other way round. On Seatalk you can have multiple senders and receivers.

Good luck.

 

[Aeolus_IV]

There was a thread a few weeks ago about NMEA/RS232 issues etc. Under the title "linking ST2000+ autopilot, GPS & wind".

Jeff.