  The point-contact spectra of tetragonal $\rm YBa_2Cu_3O_{7-\delta}$ with
$T_c=50-60~K$ are studied at various temperatures. The single-electron energy
($2\Delta_0/kT_c\simeq 17$) and its temperature dependence are determined. The
characteristic energies of quasiparticle excitations interacting with
conduction electrons in this high-$T_c$. superconductor are found to correlate
with the characteristic phonon energies. The possibility of a pair gap, which
increases with temperature, is revealed near the critical temperature.
