A fit to the relative positions of the components of PSR B0329+54, which show a lot of asymmetry. The outer cone (bold line) is skewed towards earlier pulse longitudes and both of its components fade at very different rates. The inner cone (dashed line) is skewed in the opposite direction and again shows different spectral indices for each side of the cone. Models are less reliable in the LBAs (<100 MHz) where the pulse profile is affected by scattering.