My Phantom 2 was working fine for the first week.  Now it flys out about 50 feet, then looses radio signal and returns home.

Phantom 2
H3-3D Gimbal
Stock Radio from DJI

how do you know that you are loosing radio signal? Does this now happen every single time? No abstacles between the Tx and Rx?
Are the battereis in your remote still good?

Try this, if it enteres "RTH" mode, flick the S1 switch to ATTI mode, you should have control back then without it landing automatically.

markus@egide.de Posted at 2015-1-6 00:45
how do you know that you are loosing radio signal? Does this now happen every single time? No abstac ...

The lights change from green to flashing orange.  Yesterday I tried to fly it and it happened every time when the Phantom was about 50-60 feet away (very close).  I can try changing the batteries in the radio, but they are pretty new.   I flew for a week or so with no problems.  After I installed the H3 3D gimbal it happened a couple of times and now every time...not sure there is any connection?  

The yellow LEDs just indicate that the Phantom is in RTH mode, but doesn't say why. Perhaps the radio is faulty, the antennas bad or perhaps even your Phantom Lipo is bad (low battery return home). If not done already, update all firmware. I can't see a conection with your gimbal either. If you're lucky, find another Phantom owner in your area and swap radio/Lipo and try again to narrow down the faulty part.

OK...thanks for the advice.  I'll give that a try.

markus@egide.de Posted at 2015-1-6 01:46
The yellow LEDs just indicate that the Phantom is in RTH mode, but doesn't say why. Perhaps the radi ...

I figured out the problem based on several other postings online and something I read from DSLR Pros.  TURN OFF BLUETOOTH ON YOUR GOPRO!  It causes interference and can make all kinds of crazy stuff happen.  I guess some people loose control completely.  At least mine returned to home.  I just did several test flights everything seems to be working fine.

otv@mac.com Posted at 2015-1-6 05:57
I figured out the problem based on several other postings online and something I read from DSLR Pr ...

now that you are mentioning it. If I remember correctly, DJI included an "interference protection" within the latest firmware. This may find a "strange" signal (within the 2.4 GHz band) and trigger the RTH.
Can somebody verify this?

However, wifi and Bluetooth both opperate on 2.4 GHz, just like the stock transmitter and should not be turned on.

I have the latest firmware installed.  Wireless needs to be turned off on the GoPro or you will have problems with fly aways and radio interference.