  The discovery that the Galactic SGR 1935$+$2154 emitted FRB 200428
simultaneous with a gamma-ray flare demonstrated the common source and
association of these phenomena. If FRB radio emission is the result of coherent
curvature radiation, the net charge of the radiating "bunches" or waves may be
inferred from the radiated fields, independent of the mechanism by which the
bunches are produced. A statistical argument indicates that the radiating
bunches must have a Lorentz factor $\gtrapprox 10$. The observed radiation
frequencies indicate that their phase velocity (pattern speed) corresponds to
Lorentz factors $\gtrapprox 100$. Coulomb repulsion implies that the electrons
making up these bunches may have yet larger Lorentz factors, limited by their
incoherent curvature radiation. These electrons also Compton scatter the soft
gamma-rays of the SGR. In FRB 200428 the power radiated coherently at radio
frequencies exceeded that of Compton scattering, but in more luminous SGR
outbursts Compton scattering dominates, precluding the acceleration of
energetic electrons. This explains the absence of a FRB associated with the
giant 27 December 2004 outburst of SGR 1806$-$20. SGR with luminosity $\gtrsim
10^{42}$ ergs/s do not emit FRB, while those of lesser luminosity can do so.
"Superbursts" like FRB 200428 are produced when narrowly collimated FRB are
aligned with the line of sight; they are unusual, but not rare, and
"cosmological" FRB may be superbursts.
