  We propose a string-derived model based on the gauge group $SU(5)\times U(1)$
which satisfies the stringent constraints from no-scale supergravity, allows
gauge coupling unification at the string scale, and entails previously
unexplored correlations among various sectors of the model. All supersymmetric
observables are given in terms of a single mass parameter with self-consistency
of the model determining the rest, including $\tan\beta=2.2-2.3$ and
$m_t\approx175\GeV$. A small non-universality of the scalar masses at the
string scale produces a downward shift in the right-handed slepton masses at
the electroweak scale, such that for $m_{1/2}\gsim180\GeV$ these particles
become lighter than the lightest neutralino. This cutoff in the parameter space
entails the imminent discovery of charginos at the Tevatron via trilepton
events ($m_{\chi^\pm_1}<90\GeV$). Also, the lightest Higgs boson
($m_h<90\GeV$), the lightest chargino, and the right-handed sleptons
($m_{\tilde\ell_R}<50\GeV$) should be readily observable at LEPII. We also
discuss the model predictions for $B(b\to s\gamma)$, $(g-2)_\mu$, $R_b$, and
the prospects for direct neutralino dark matter detection.
