The feeding point of the tower is close above the middle cantilever, where the cage ropes are interrupted by insulators. The feeding voltage lies between the upper rope cage and the tower. The power is brought to this point inside the tower by an open coaxial line. The outer conductors are connected to the tower and the inner conductor is led to the upper rope cage by insulators.
Near the top cantilever additional short circuit ropes are connecting the cage ropes and the tower corner legs. Since the upper part of the rope cage and the tower act also as a coaxial line this short circuit defines the length of this line and consequently the value of a reactance being parallel to the impedance of the feeding point.
For the computation using the Method of Moments a model was designed which did not correspond completely with the real antenna. The computer model comprised only four instead of six cage ropes.
The diameter of the four ropes was increased being equivalent to the diameter of six ropes. Also the webb structure of the lattice mast of the tower was not taken into account. These simplifications had to be done because of the complexity of the antenna which with respect to the computers of 1988 would have meant not realistic storage capacity and computing time. Nevertheless the computer model contained all important characteristics with satisfying accuracy.