  Our high time resolution observations of individual pulses from the Crab
pulsar show that both the time and frequency signatures of the interpulse are
distinctly different from those of the main pulse. Main pulses can occasionally
be resolved into short-lived, relatively narrow-band nanoshots. We believe
these nanoshots are produced by soliton collapse in strong plasma turbulence.
Interpulses at centimeter wavelengths are very different. Their dynamic
spectrum contains regular, microsecond-long emission bands. We have detected
these bands, proportionately spaced in frequency, from 4.5 to 10.5 GHz. The
bands cannot easily be explained by any current theory of pulsar radio
emission; we speculate on possible new models.
