I decided to do a direct comparison between several antennas to determine the best setup for distance on my Phantom 2. I have compiled the results here so everyone researching this can learn from my results.
Here is what I learned:
1. It is important to match the antenna style whenever possible.
2. Stock antennas don't work very well, obviously.
3. The Cheap Clover style antennas, don't advertise which direction they are polarized (RHCP or LHCP).
4. Cheap Helical Beam antennas might be twisted in the wrong direction, and also not advertised (RHCP or LHCP).
5. With what I had available at the time, the matching clover set gave me the best results, as the cheap Helix antenna appeared to be LHCP.
6. After rebuilding the Helical antenna to RHCP, signal was greatly improved at distance while using the good antenna (Circular Wireless SPW58).
