Thread: About 37xx converted to 34xx satellites reception accuracy

Originally Posted by lolypop000

@isg

Try this:

In folder .System create new folder with name GPS and in this folder create new folder with name rnx and then in this folder create one folder with name eph and one folder with name pred.
Turn off your nuvi, go outside and whait for satellite lock and then go back to Pc and look if you have some files in eph and pred folder.

Hi,

I followed your steps but nothing changes inside the folders.
I am following all the posts here, but no success selecting Cold Star and Ephemerides.

[]'s

The test results.
I have copied the dir sent to me by lolypop000 to /.system. Renamed mine in order not to be read by system and then started the unit.
Frankly speaking I was prepared for worst case scenario, but GPS started smoothly, found satellites and the accuracy was good. I have never seen my GPS showing 4 m. accuracy, so I was happy. I was standing to get the above accuracy Weather here is foggy and I think that 4 m. is good accuracy.
I have done lolypop000 and Caty procedure described in posts [Only registered and activated users can see links. ] and [Only registered and activated users can see links. ]. Good and fast fix so far. And then go back to the computer.
GPS dir was there, it was not empty. All subdirectories are there, but also I have those tree small files shown in my post #89, i.e. ARC.BIN, BEE.BIN and mt.nvm. Have to say that they were not there when I have extracted lolypop000’s directory. They have even same sizes.
In sub directories: all files were there, none of them changed after extracting process, including MSL_log.txt.
All above make me think that for my GPS the directory structure sent by lolypop000 does not work for me. The GPS unit has better accuracy now for sure, but I will test it on a long trip and will report the results. I suppose that during years Garmin have changed something in the hardware which allows usage of rxn technology. May be, as other guys said already, that is one of the main hardware differences between 3790 and 3490. I have bought my unit in September 2010. If yours are newer that will explain the things.

I think that we found something out from this.

1.) If you don't have rxn folder and inside poly, seed, eph, pred then accuracy is bad.

2.) If you remove Arc.bin, Bee.bin and mt.nvm, create procedure for satellite and then nuvi makes these files by himself then you have better accuracy

One of this two is correct, but which one

p.s.
If i remember correctly Caty have rnx folder and bin files from the beginning and have good accuracy.
I think that solution for good accuracy is rxn folder, but we must whait for sig to test and report.

@Neil
Do you have rxn folder in your GPS folder?

Originally Posted by lolypop000

I think that we found something out from this.
1.) If you don't have rxn folder and inside poly, seed, eph, pred then accuracy is bad.
2.) If you remove Arc.bin, Bee.bin and mt.nvm, create procedure for satellite and then nuvi makes these files by himself then you have better accuracy

One of this two is correct, but which one
p.s.
If i remember correctly Caty have rnx folder and bin files from the beginning and have good accuracy.
I think that solution for good accuracy is rxn folder, but we must whait for sig to test and report.

On my 37>34 there is no RNX or RXN folder, but there is an arc.bin etc. files. Accuracy (tested today) up to 4 meters.

Originally Posted by Neil

Nup. Just Arc.bin, Bee.bin and mt.nvm.

Ok, now i am confused.

On some nuvi work with no rxn folder but on some nuvi won't work, but work when you add rxn folder and inside eph_28....... files or if you remove arc,bee, and mt files before you do procedure and nuvi then create again this files by him self, when you follow procedure.