  A multi-frequency, multi-configuration study has been made of the compact
radio sources in the Galactic Center Quintuplet and Arches stellar clusters
using the Very Large Array. Ten radio sources have been detected in the
Quintuplet cluster. The majority of these radio sources have rising spectral
indices and are positionally coincident with young massive stars that are known
to have powerful stellar winds. We conclude that the three most compact of
these sources are produced by stellar wind emission; thus, mass-loss rates can
be derived and have an average value of 3 x 10^-5 solar masses/year. The
remainder of the sources are likely to be a combination of stellar wind
emission and free-free emission from surrounding ionized gas. In three cases,
the radio sources have no stellar counterpart and the radio emission is thought
to arise from compact or ultra-compact HII regions. If so, these sources would
be the first detections of embedded massive stars to be discovered in the
Galactic center clusters. The radio nebula associated with the Pistol star
resembles the nebula surrounding the LBV star Eta Carina and may be related to
the stellar wind of the Pistol star. Ten compact radio sources are detected in
the Arches cluster and are interpreted to be stellar wind sources, consistent
with previous findings. Several of the sources show moderate variability
(10-30%) in their flux density, possibly related to a nonthermal component in
the wind emission. A number of radio sources in both clusters have X-ray
counterparts, which have been interpreted to be the shocked, colliding winds of
massive binary systems.
