try to put a LR03 1.5v battery in the middle of the CF black cover, play moving the battery over it, and see the result. for me is exactly the middle, putting it vertically, i see gain with AP I can't reach.
I don't know why, boring afternoon did the rest.
scheme:
CF card
.....______
..../####/
.../#(o)#/
../#•##/
..‾‾‾‾‾
with LR03 battery in the middle
try with other CF, no glue please, removable mod