  A theory of pulsar radio emission generation, in which the observed waves are
produced directly by maser-type plasma instabilities operating at the anomalous
cyclotron-Cherenkov resonance $\omega- k_{\parallel} v_{\parallel} + \omega_B/
\gamma_{res}=0$ and the Cherenkov-drift resonance $\omega- k_{\parallel}
v_{\parallel} - k_{\perp} u_d =0$, is capable of explaining the main
observational characteristics of pulsar radio emission. The instabilities are
due to the interaction of the fast particles from the primary beam and the tail
of the distribution with the normal modes of a strongly magnetized
one-dimensional electron-positron plasma. The waves emitted at these resonances
are vacuum-like, electromagnetic waves that may leave the magnetosphere
directly. In this model, the cyclotron-Cherenkov instability is responsible for
core emission pattern and the Cherenkov-drift instability produces conal
emission. The conditions for the development of the cyclotron-Cherenkov
instability are satisfied for both typical and millisecond pulsars provided
that the streaming energy of the bulk plasma is not very high $\gamma_p \approx
10$. In a typical pulsar the cyclotron-Cherenkov and Cherenkov-drift resonances
occur in the outer parts of magnetosphere at $r_{res} \approx 10^9 cm$. This
theory can account for various aspects of pulsar phenomenology including the
morphology of the pulses, their polarization properties and their spectral
behavior. We propose several observational tests for the theory. The most
prominent prediction are the high altitudes of the emission region and the
linear polarization of conal emission in the plane orthogonal to the local
osculating plane of the magnetic field.
