The nature of electrostatic field driving the equatorial electrojet was studied using a coherent backscatter radar at Thumba. The doppler spectra of radar echoes from ionization irregularities in the E-region, during periods close to the morning and the evening electrojet reversals, show that the electric field, in general, is stronger during the pre-reversal periods than during the post-reversal periods. Similar results for the evening hours were reported earlier from the radar studies conducted at Jicamarca. This indicates that this effect is likely to be present at all the equatorial stations.