In previous publications [A. K. Ram and S. D. Schultz, Phys. Plasmas 7 , 4084 (2000) ; A. Bers, A. K. Ram, and S. D. Schultz, in Proceedings of the Second Europhysics Topical Conference on RF Heating and Current Drive of Fusion Devices , edited by J. Jacquinot, G. Van Oost, and R. R. Weynants (European Physical Society, Petit-Lancy, 1998), Vol. 22A, pp. 237–240] it has been shown that, in overdense plasmas of the type encountered in spherical tori, electron Bernstein waves can be excited in a plasma by mode conversion of either an externally launched X mode or an O mode. The electron Bernstein waves are strongly absorbed by electrons in the region where the wave frequency matches the Doppler broadened electron cyclotron resonance frequency or its harmonics. The strong absorption also implies that electron Bernstein waves are emitted by a thermal plasma. These waves can then mode convert to the X mode and to the O mode and be observed external to the plasma. In this paper an approximate kinetic model describing the coupling between the X mode, the O mode, and the electron Bernstein waves is derived. This model is used to study the mode conversion properties of electron Bernstein wave emission from the plasma interior. It is shown, analytically and numerically, that the energy flow conversion efficiencies of the electron Bernstein wave to the X mode and to the O mode are the same as the energy flow conversion efficiency of the X mode to electron Bernstein waves and of the O mode to the electron Bernstein waves, respectively. This has important experimental consequences when designing experiments to heat overdense plasmas by electron Bernstein waves.