Spectral index map of the high resolution central region of 3C 293 from 144–1360 MHz at 0.28′′ × 0.23′′ resolution. The map is overlaid with 1360 MHz contours with levels at: (5, 10, 20, 40, 65, 150) × σ_RMS where σ_RMS = 1.4 mJy beam⁻¹ is the local RMS noise in the smoothed MERLIN image. The inner lobes clearly show a distinct spectral index population from the diffuse emission around them.