The equalization problem is a problem of estimating a signal transmitted over a telecommunication channel. This problem has a range of applications in telecommunications. In this paper, we consider a version of the problem in which the channel model contains an uncertainty. Our goal is to design a robust finite impulse response (FIR) equalizer which guarantees certain bound on the worst-case estimation error. The design procedure presented in the paper relies on the recent progress in maxdet convex optimization. Another result used in the paper concerns minimax optimal control and filtering of uncertain systems with relative entropy constraints on the uncertainty.