DSC VHF RADIO FITTING PROBLEMS

[corky]

I recently bought a new m-tech dsc vhf from piplers and am having a few problems with the fitting. I have wired the radio up and everything is working as it should as far as transmit and recieve goes anyway ! The problem I am having is it doesnt recieve GPS co-ordinates from my garmin 276c ? I have wired everything as best I can understand from the two different manuals and even tried a couple of swap rounds but still nothing ! Would appreciate any advise from anyone who knows anything about boat electrics or advise on who to take it to ??

chris

[Manic Moore]

 

 

Chris

 

Have you had a look at your comunications tab on your Garmin? I have wired one or two but generaly work from the diagrams and although they are not always clear I have managed to sort it. Are you local? I don't mind popping over to have a poke around before you start spending your cash.

 

 

Regards

 

 

Gordon

[corky]

Hi gordon, yes I have messed about with the coms tab but working in the dark a bit. Your offer of help is appreciated - I live in Hamworthy but would gladly bring the boat to you if you had time to have a look.

thanks

chris

[Bob F]

Chris/Gordon,

 

If you have no luck I will be in Salterns on Monday evening and could drop by Hamworthy on my way home to Blandford to have a look. It will probably be sometime between 6 and 8pm.

 

Let me know.

 

Bob F

[corky]

Thanks Bob, good of you to offer to help....

Edited April 10, 2008 by corky

[djredrupp]

have a look through the NMEA settings on the garmin unit. On our eagle it was something that you need to 'turn on'.

 

Just a thought!

 

Dan

[codless]

i have fitted a few over the years and each case you have to go through the menus on your gps and enable the bit that say send to gps or something like that

[corky]

Thanks for the hints guys - I have checked and the NMEA is definatley turned on, the Baud is set at 4800 but when I ask it to scan I keep getting the check wiring message. There seems to be a conflict as to how to wire the data cable - the garmin gps manual tells me its yellow data wire is com 1 input and has a diagram showing the vhf should also be earthed to black ( I assume this is the brown data lead from the vhf as there is no black data lead )This appears to be in addition to the black and red power leads. The manual with the vhf however tells me its data cable brown lead is + and the red is - Now does the + represent data in or data out ??? doesnt tell me that anywhere....

Hoping that Gordon may be able to make sense of it on Sat.

[Brian]

Have you selected the correct Interface Format?

 

Garmin units allow six different formats:

1. GRMN/GRMN

2. None/None

3. RTCM/None

4. RTCM/NMEA

5. NMEA/NMEA

6. None/NMEA

 

Your Garmin probably defaults to Garmin/Garmin. You need to select NMEA/NMEA.

[Paul D]

Chris,

 

I think from your description the wiring is your problem. I think your assumption re: the brown lead being the earth is incorrect.

 

On my GPS to VHF link this is connected using a shielded cable with a BNC plug. The shield is earthed to the earth on the GPS ( ie. The chassis of the radio is connected to the negative side of the battery which is connected to the braid of the connector which in turn is connected to the black negative GPS wire - which is connected to the negative side of the battery ).

 

Have you tried connecting the yellow lead on the GPS to the brown one on the radio and the red lead on the radio to the black power lead ( which is connected to the negative side of the battery ). - although make sure the red lead really is the negative data cable or could be interesting !

 

 

[Paul D]

Provided the red lead on the radio really is the data -ve cable then definitely connect this to the ground ( battery earth side / negative power cable ).

 

The data +ve cable from the radio goes to the GPS yellow lead.

 

Set up your NMEA stuff and it will all spring into life

 

[corky]

Brian please peruse the following data formats my Garmin is showing and advise which to use. I think I have tried all the possibilities containing the NMEA but possibly not all wiring options in each. The list in my format menu is as follows and is written exactly as it appears.

 

Garmin Data Transfer (think this one is for my pc)

Garmin DGPS

Garmin Remote Sonar (worked out for myself this ones unlikley )

NMEA In/NMEA Out

RTCM IN

RTCM IN/NMEA Out ( I dont think I tried this one)

RTCM IN/TEXT Out

TEXT OUT (got a mobile for this)

NONE

 

Just out of interest what does RTCM stand for ?

thanks

chris

[duncan]

for the garmin I think it's the interface tab under setup - make sure it's set to NMEA in/out rather than the default Garmin data transfer. the default data settings should work fine.

 

brown wire will be NMEA+ve and this connects to the NMEA in wire on th eradio unit. If this is the sx35 then that's the brown one as well. Black (earth) acts as NMEA-ve and should be directly conected to the radio's NMEA-ve wire which is the red one. It's not good enough to have them 'effectively connected' via mutual connection via the boats earth.

 

apart fromthat the onlu other 'key' is that for some units you need the MMSI number programmed into the unit for the unit to display the lat long on screen - don't know this unit.

 

I suspect that all of the above is only restating what you have already done but there may be something.

[duncan]

radio technical commission for maritime services

[Paul D]

Its for an Icom but same principle.

 

Icom to Garmin Wiring

[AHoy]

Chris, PM sent

[corky]

Duncan could be on to something here which brings me to my next dumb ass question. How do I register for my MMSI number and can I do this online ??

[Paul D]

Chris,

 

Duncan may be onto something, but from the description of the way you have wired up the wiring was wrong. ( ie. Your brown lead needs to connect to GPS yellow lead and the red lead needs to connect to the GPS black lead which is connected to the negative side of the battery ).

 

Is it connected like this now ?

 

[Paul D]

The ofcom website is here :-

 

OFCOM Register

[corky]

Paul I did try this configuration however I may not have been selecting the correct data format at the time. I took the boat back to the compound an hour ago to avoid the FPO becoming unsettled due to total lack of contact

My current plan is to try your suggestion after work tomorow........

[Paul D]

Cool - Also, noted that Bob F is watching, so if it is wrong I am sure he will say so

[Bob F]

If none of the above things work, make sure you are actually using the center core of the garmin cable, and not the shield as the signal conductor.

 

The Garmin cables are notoriously thin, and it's easy to mistake the shield for the center core. This is what I found when another member was having a problem with their set up. Or check that the shield is not shorting to the center core.

 

But the most common problem is incorrect settings for the NMEA on the garmin unit or on the VHF.

 

BF

[great white]

Bob I have been ages waiting for matt to look at the link between my Lowrance my Icom VHF and the Radar.

 

Do you fancy a trip sometime while I pick your brains.

 

Charlie

 

 

[Bob F]

Charlie

 

Sounds like a plan. Not sure when though. This weekend is fully booked already and so is next week end. What about dropping by the boat on Monday evening? I will be at Salterns from 5pm to 6pm, so I could drop by afterwards (and then onto Corky??).

 

BF

[great white]

Thanks BOB

 

I have the boat back on her mooring but I could bring her in to the Marina on Monday at 5 ready if you want.

 

I was going to call you to see if you wanted to join us tomorrow, but I presume you and Adam have a shopping list to sort out

Call me when its conveniant

 

Charlie