  In the ILD concept, a TPC is foreseen as the main tracking device. The
MediTPC prototype has been developed at DESY to study the properties of Gas
Electron Multipliers (GEMs) and to perform resolution studies. Studies of the
influence of oxygen contaminations on the electron signal are presented here.
Further, resolution results with new pad planes with 1.27x7.0 sqmm pad pitch
and in high magnetic fields are shown.
