Garmin GMR 18 xHD - I can not power it up

[pelakuti]

Hi, my name is Pelayo, from Spain and I am a cadet on this electronics world.
I have the dream of having my radar on OpenCPN from many years ago and I am right now on the way to try to achieve that goal thanks to the developers of this pluging. I am very grateful. Thank you.
I bought the GMR 18 xHD because of the price and because I dont have any MFC, just the computer, and I read on the wiki that this model would be fitting for this purpose.

I can not power it on and I want to tell you the steeps that I have followed in order to find the mistake:
Right now the antenna is connected to the 24V terminal block bus from my boat. I will take the radar home and connect it directly to a battery to continue the testings here.
I bought the famous Ampherol MRJ 570 but I did not solder the cables on it and I did not attach any switch (I know that on the wiki is written that this is compulsory) because I have seen pictures on the net from other users and they are all different
https://imagizer.imageshack.com/img924/3780/FeLRYr.jpg
https://imagizer.imageshack.com/img924/9759/AAnDcG.jpg
https://imagizer.imageshack.com/img923/4978/32LudB.jpg
Wich one of the three is the correct? Once I know this for sure I will solder this and attach the switch.
After reading the wiki, in my opinion the connection should me made between this 2 pins:
https://imagizer.imageshack.com/img922/4884/b3eYFR.png
Am I right? I proceed with the soldering and the switch?
Another question is if I have to solder any aditional cable and if I have to cenect it somwhere else? I know I am in the 2nd scenario (no MFD, directly to PC) but in the picture of the scenrio 1, the ground symbol made me crazy. Do I have to connect the ethernet pin 5 to the battery? Is not just to connect pin 5 from the Amphenol to the "conector shell, chasis ground of the Amphenol" too?
Regarding to the ethernet cable that goes to the computer: does it has to be any kind of special apart from beeing cat 5 minimun? I am using a simple cat6e. Do I have to cut the 5 wire from this cable?

I am desperate, I tought that this would be easy but has become a nightmare to me. I could not power it on, the Status LED is all the time off. In all the forums I have read, I found people with the same issues all of them where not replayed. I have read all the tabs I found on google related to the pin 5
I am praying on my knees for your help and that maybe the origin is just in the non soldering.....
Apologize, is the first time I do this and I have no many idea.
Thank you very much and cheers for your amazing job!

[markcouz]

With power supplied to the radar and turned on, the wire connected to RJ45 Pin 5 of the radar cable needs to be shorted to the shielding of the same radar cable in order to activate the radar.

You can have power permanently supplied to your radar and control on/off state by installing a switch between Pin5 and the sheild, or you can install a permanent wire between Pin5 and the shield and then control on/off state by switching power.

Google "RJ45 Pinout" so that you can have a better understanding of what needs to be done - if you already have the amphenol connecter then this is the easiest place to do it.

[markcouz]

I looked a bit more closely at your pictures and they are ALL correct - but if you need someone to pick 1 then I would suggest that you copy the photo with the red/yellow wire and black switch.

Note that the Garmin Radar waits to see this Pin5/Shield short before it will come out of standby and start transmitting.

[pelakuti]

Thank you very much markcouz.
The picture with the wires in red and yellow is from the original developer so I agree.
The problem is that it looks like the cable is soldered to the pin 4 (lower line of pins) and not the pin 5 (upper line of pins). Am i right?
Thank you.

[markcouz]

Yes, I missed that looking at small pic on my phone - use his method but Pin5 as shown on diagram.

[bdbcat]

"Yes, I missed that looking at small pic on my phone - use his method but Pin5 as shown on diagram."


Depends on which side of the adapter that you connect the scanner to.
I promise that as built, it works fine for me, with the scanner plugged in at TOP, and pc plugged in at BOTTOM of photo. Really.


Good Luck


Dave

[pelakuti]

Originally Posted by bdbcat

"Yes, I missed that looking at small pic on my phone - use his method but Pin5 as shown on diagram."


Depends on which side of the adapter that you connect the scanner to.
I promise that as built, it works fine for me, with the scanner plugged in at TOP, and pc plugged in at BOTTOM of photo. Really.


Good Luck


Dave

I obsolutely belive you. I have post new pics and valuable links in the openCPN github and I would say that supports 100% your thoughts, bdcat.

Before this week is ended I am going to solder the cables in your way.
Any recomendation for the AWG of the cables and the switch?

Thank you all.

[markcouz]

Originally Posted by pelakuti

I obsolutely belive you. I have post new pics and valuable links in the openCPN github and I would say that supports 100% your thoughts, bdcat.



Before this week is ended I am going to solder the cables in your way.

Any recomendation for the AWG of the cables and the switch?



Thank you all.

It is a signal only with negligible current - 0.5mm (preferably tinned and stranded) would be more than adequate. Any spst (on/off single pole) switch will do so long as it is in a moisture free environment.

[pelakuti]

Bdcat, you are the grearest of all times! Is wworking fine!!
Thank you very very very much! You are amazing!
And of course thank to everyone else that replied to me with great advices!!
Thanks guys! what an amazing forum!!