I've been running Earthworks > Denecke PS2 > R09 and loving it. The Earthworks are power hogs. I tried to run them once on a single 9v battery. I thought it would be fine - it worked for hours with Octava MC012s. After about 30 min, they crapped out.
I have since wired a mono 1/8 connection to a Radio Shack 9.6v rechargable battery pack connector, and have used that rechargable battery, works great, sound nice and clean. I don't know if you have the ability to connect external power with the Phantom II, but look into using the Rat Shack 9.6v batteries, or even the ever popular Walmart battery, assuming it runs on 9v power.