  Direct-collapse black holes (DCBHs) forming at $z \sim$ 20 are currently the
leading candidates for the seeds of the first quasars, over 200 of which have
now been found at $z >$ 6. Recent studies suggest that DCBHs could be detected
in the near infrared by the James Webb Space Telescope, Euclid, and the Roman
Space Telescope. However, new radio telescopes with unprecedented sensitivities
such as the Square Kilometer Array (SKA) and the Next-Generation Very Large
Array (ngVLA) may open another window on the properties of DCBHs in the coming
decade. Here we estimate the radio flux from DCBHs at birth at $z =$ 8 - 20
with several fundamental planes of black hole accretion. We find that they
could be detected at $z \sim$ 8 by the SKA-FIN all-sky survey. Furthermore, SKA
and ngVLA could discover 10$^6$ - 10$^7$ $M_{\odot}$ BHs out to $z \sim$ 20,
probing the formation pathways of the first quasars in the Universe.
