Preliminary measurements of the ion component of the incoherent scatter spectrum are presented. The observations show qualitative agreement with theory if the effects of negative ions and experimental sources of spectral broadening are considered. The measurements indicate that neutral winds can be measured down to about 65 km during the daytime at Arecibo. Accuracies of 2.5 m/sec for the horizontal components, and 0.6 m/sec in the vertical component can be obtained below 80 km after one-half hour integration.