An investigation is made of tank physics issues which affect simulator fidelity of the baseline SXTF design. Detailed, three-dimensional calculations are made out to 500 nsec using the Cartesian SOS code. The first calculation considers the SGEMP response of an idealized FLTSATCOM geometry in the cylindrical SXTF simulator. The second considers the response of the identical satellite in a free-space environment. A comparison of calculated satellite responses demonstrates that, for the configuration studied, the cylindrical SXTF simulator provides a good approximation to the free-space environment. Similar results were previously obtained for a spherical simulator geometry.