In an experiment simulating certain characteristics of the equatorial electrojet plasma (viz. &ngr;e≪&OHgr;e, &ngr;i>&OHgr;i, ?, Δn⊥?), low frequency (&ohgr;?&OHgr;i) waves travelling in ?¿? direction are observed. These waves are identified to the modes generated by the cross-field instability. The spectrum of the potential fluctuations has an index &bgr;?-5.8. The observed spectrum also indicates generation of a mode by wave-wave interaction of two modes, as well as a m=0 mode stationary in the ?¿? direction.