I then put the sat on roof of trailer which is the highest point around and NO obstructions from the southern sky, still no signal.
Another thought is when you indicate that you don't get a signal, are you looking at all of the satellites in your satellite setup screen? With DirecTV you can only view the Standard definition satellites, not the High Definition ones. So the G2 only "sees": DIRECTV Satellites: 101° or 119°. Even then, it will not see all transponders, only some are active. Satellites 99, 103, 110 for instance likely will not show as receiving a signal.
You can use an app on your smartphone such as "Dish Align" to find the direction for just those satellites and set your dish to be able to see the horizon in the indicated direction.
The previous guidance about antenna type is also spot on.
Another tip, once you get it working, go into the Display/Preferences on DirectTV settomgs and select the option to only display SD channels (Hide HD Channels). This will save sifting through all of the HD channels and inadvertently selecting one of them.