[en] Presented is the calculation of electromagnetic fields excited by currents of Compton electrons arising in the process of 3MeV gamma-quanta (initiated by neutrons) interaction with atoms and molecules of the air. The gamma-radiation pulse, currents of Compton electrons, and emitted electromagnetic pulse have characteristic time about several tens of microseconds. It is shown that registration of instant gamma radiation leads to radio pulse formation which is similar by its duration and form to observed pulses. To obtain more precise results, it is necessary to take into account the effect of underlying surface on the processes of neutron deceleration, volumetric distribution of secondary gamma radiation sources and also on the currents arising in the underlying surface itself. When the time is short it is necessary to account for non-linear effect along the field in the current region. But when the time is long it is necessary to take into account air conductivity conditioned by ions