First off.
Welcome!
Marius Ciortea .
You have came to the right place for information. Enjoy your time here. Be sure to read all you can. There are tons of threads on just about any subject you can think of that has to do with the quad-copters. The search function works well here. Use it often, you will find what ever you need. In that rare case that you can not, there are great people here to help. Thanks for coming to Phantom Pilots! You are family now.
If you need any help/parts, please visit:
www.PhantomHelp.com
As for your distance problem, that seems to be strange. I would assume since you are in the middle of nothing, you don't have wifi interference. Even with a slight change in weather conditions you should not have dropped that much distance. Do you have you controller pointed at the direction of the bird? Antenna position can mean alot as well. This may sound callous, but did you drop the remote at all? Reason I ask this is it could be possible that you may have jarred the connection loose for the antenna which would give those kind of results.
Experience? Are you new at this? These are some of the questions that folks will ask. Please don't get offended when they are asked. People here just want to help you and they need as much info as you can give them. You can also search the forums using key words like signal loss, antenna, and the sort. the magnifying glass in the upper right corner of the screen will give you a search bar.
Like I said, the more info you can give, the better a response you can get. There are some really good people here. Newbie? or not. They will help if they can.
Mike