Connecting Navman Plotter to NASA DSC radio

[Robin]

Help!

I have just replaced an old and now dead Shipmate GPS that used to run the NASA DSC as well as the Yeoman paper plotter, with a nice new Navman 5600 plooter/GPS. I have connected all up as the manuals say, and turned on all the NMEA sentences and NMEA output from the Navman and the Yeoman is running OK (so NMEA is getting to that as it should) - but the NASA VHF will not show the Lat/Long as it should! I have tried every combination of connections for the 2 NASA NMEA leads to no avail so I am wondering if I need to change something in the NASA setup, there is and option for example to turn 'NMEA Checksum' on/off, it was 'on' with the old Shipmate.

Has anyone succesfully linked a 5600 Navman and NASA SX35, if so do you remember HOW?

I've asked NASA but they are apparently not au fait with the Navman and have suggested I call them from the boat and that they talk me through a re-set procedure to restore the NASA defaults and then to re-install the MMSI in case that helps. I may do that but I'm hoping one of the forum experts will know how it really should be done.

TIA

Robin

 

[MarkJohnson12345]

We struggled connecting a Garmin GPS to a NASA DSC radio on my friends boat last week.

Got it working in the end as per advice from a thread on this forum.

The Nasa only wants one line from the GPS, the other goes to the earth cable (black) back to the battery.

Quite logical really. My own boat kit has a NMEA + & -, so took my brain a small leap to understand the different wiring logic.

Don't know if that info is of any use alas..................

Good luck

 

[Robin]

Thanks Mark. Yes that was the case indeed wiring the NASA to the old (Shipmate) GPS but it doesn't work with the Navman nor does it with the 2nd NASA (-ve/return) wire connected to either Navman -ve or Navman shield/ground -ve (which according to the Navman manual are connected together in the plug anyway!

Robin

 

[crossbones]

The nasa sx35 has a ballanced input. The brown wire on the nmea cable is nmea positive and the red wire nmea negative (sometimes called nmea reference ) You must connect both wires to the nmea + and nmea- of the plotter. If there is no nmea- then the negative power supply will be the reference so connect the red wire to supply negative. It looks odd connecting a red wire to negative but that's how it goes.

 

[pvb]

Is \"Autopilot out\" turned on?

I used to have a Navman 5600 - very nice product indeed. Before it will output NMEA sentences, you have to go into the Comms setup and turn "Autopilot out" on (the factory default setting is off). If you've connected the Navman white lead to the NASA brown lead, and the Navman black to the NASA red, it ought to work. If it still doesn't, try going back to the Navman comms menu and turn off all the NMEA outputs except RMC (which is the only sentence the NASA wants). That might get the NASA working, but could upset the Yeoman! Trial & error after that.

 

[Robin]

Re: Is \"Autopilot out\" turned on?

Thanks. Yes I found the Autopilot on/off and have it set to on, plus I turned ALL the sentences on including RMC. Later I think I tried turning all the sentences off except RMC and GLL so maybe I can try just RMC. The Yeoman only needs a position I guess as I'm only using it now to put position on a paper chart, not to download/upload waypoints, it seems to work OK whatever I do so I have that connected OK.

I do have the NASA brown lead connected to the Navman white and the NASA red to the Navman black (I tried either and/or both blacks on the Navman, though the manual says they are connected in the plug anyway). Previously with the Shipmate GPS it worked with only the Brown NMEA lead from the NASA connected, presumably it found the NMEA -ve reference from the common ground. I don't currently have the Navman NMEA input leads connected, only the outputs but I did have them all on place on the first trial!

I'm wondering a little about the NASA NMEA Checksum on/off option as the NASA manual (not the easiest read) seems to suggest it needs to be 'on' for earlier versions of NMEA - it was 'on' previously when using the old Shipmate GPS.

There is another symptom in that the NMEA output from the old Shipmate also found it's way via the autopilot/radar to the Seatalk system and would in fact give a position to the old Raytheon plotter if the Raytheon's own GPS went out. This is not happening either now so it seems that even though the Yeoman likes what it gets from the Navman neither the NASA NOR the Raytheon do! /forums/images/graemlins/confused.gif

Robin

 

[Robin]

Thanks. Yes I did that first time round. See my reply also to PVB, this is beginnining to drive me mad and I'm glad I don't do it for a living!

Robin

 

[dmayes]

Have you tried connecting it "one at a time". You indicate that it is connected to at least three others and the signal may be degraded. Try just driving the Nasa from the GPS without the others being connected and so on.

 

[philip_stevens]

Robin,
Do you have the colour connection supplement supplied by Navimo (Plastimo)??
If not, send me a PM with your email address, and I will attach the supplement to your address.

I also had problems sending NMEA to my old Furuno radar. Nothing I sent from the Navman 5500 GPS would show as Lat/Long on the radar. I then connected the radar to my old AP-Philips Mk9 GPS - and there was lat/long.

The NMEA Lat/Long is OK with the input to the Navman 7200 DSC VHF, as it is also sending full information to the Autohelm Interface Unit to convert to Seatalk for the Autohelm ST3000, and to the Yeoman Sport Plotter.

Why the NMEA info from the 5500 is not showing on the radar?? I know not.

BTW. I have spoken to both Plastimo (Mark) and Yeoman (Robin), and both say that information of plotted positions cannot be uploaded to the 5500.

The same is with my dGPS I bought years ago. There is no input to the 5500 from this - only WAAS/?? built-in differential will work.

 

[Robin]

Philip

Thanks. I have the colour code wiring plan in the Navman manual which shows the white NMEA OUT lead and the black NMEA ground as the connections to go to the NASA NMEA IN (brown) lead and the NASA NMEA -ve (red, strange choice I know). Is your info any different?

I guessed as much that the Yeoman wouldn't upload to the Navman even though the guy at SBS said it would but that doesn't matter to me as it is only used as a lazy plotting on paper aid these days and this it is doing OK.

Robin

 

[Robin]

I will try the one at a time and direct approach, thanks for the suggestion. All I did before in the first instance was to swap the NMEA 'IN' and ground/reference leads from the old Shipmate with the equivalent ones from the Navman, which worked only for the Yeoman (after I turned on 'autopilot output' and NMEA sentences from the Navman).

Robin

 

[philip_stevens]

The supplement sheet shows in better form, the connections between the 5500 and 7200, and between other GPS's and the 7200. It may give you a better idea of the connections.

One other point - if you bought the plotter early last year, the software may need updating.

The software that was in the 5500 had a glitch that froze the screen. The update cleared this problem.

 

[pvb]

Just a thought...

Is it possible that the NASA has defaulted to not showing Lat/Lon? You can check that this function is turned on in the Data Set part of the Menu function. You could also try turning the NMEA Checksum on and off.

 

[Robin]

Re: Just a thought...

Yes I thought that too. L/L was 'on' but I tried turning it off then back on again to no avail. The Checksum (whatever that is ) was 'off' I think and I tried it with it 'on' as well, at least I think I did! trouble is by then there was steam beginning to cloud clear thinking and I was also trying variations on a theme with the wiring (at least with the NMEA -ves/ground wires). With the old Shipmate setup only the brown NASA NMEA lead was connected, there must have been a common ground by another route and if I remember rightly when I connected that one originally it would NOT work with the NASA red NMEA connected to -ve/ground as it was supposed to be! There are dark forces at foot here I'm sure and I need to find the right incantation to use, probably not the ones I have used so far!

Robin