On this particular keyfob, I am pretty sure the antenna is the printed circuit trace that runs around the outside of the board. In the picture, you can see one trace that has lots of holes in it. This would be the ground plane side. The other trace that comes out of the circuitry in the upper left side of the picture and runs around the perimeter of the board on the left side is the "hot" side of the antenna.These traces are "tuned" to the frequency of the transmitter and lengthening or shortening them would probably just "reduce" the range, not increase it since you would be de-tuning the antenna. In other words, put in a fresh battery and leave the transmitter alone. As someone else said, you might be able to increase the range if you could add a better antenna to the receiver but I don't even know where the receiver is located on the car....does anyone know?
