Reducing the exploration depth of the TEM sounding method by measurement at earlier times necessitates decreasing size of the transmitter loop. This causes problems in measuring TEM response at both early and late times. The early time problem is associated with fundamental constraint caused predominantly by the transmitter loop inertia. As the transmitter loop decreases, its intrinsic response decreases much slower compared to that of the earth. At late times, instead of measuring the earth's transient response one measures the receiving unit's intrinsic response. Its initial amplitude is small, but it decreases so slowly that, eventually, its contribution to the total transient response becomes predominant. This problem is technical. It can be solved by eliminating or reducing the impact of the voltage pulse induced in the receiver loop during the current turn-off in the transmitter loop.