  We show that radio bursts from cusps on superconducting strings are linearly
polarized, thus, providing a signature that can be used to distinguish them
from astrophysical sources. We write the event rate of string-generated radio
transients in terms of observational variables, namely, the event duration and
flux. Assuming a canonical set of observational parameters, we find that the
burst event rate can be quite reasonable, e.g., order ten a year for Grand
Unified strings with 100 TeV currents, and a lack of observed radio bursts can
potentially place strong constraints on particle physics models.
