  Podkletnov effect [Physica C (1992)] consists in a decrease in weight (up to
2 wt. %) of arbitrary samples placed over a massive YBa2Cu3O6+d (YBCO) disk,
which is in the superconducting state and under the influence of an alternating
magnetic field. It has been pointed out that the partial weight loss may be a
result of energy state existing in the superconducting disk at low
temperatures. There are known unsuccessful attempts to reproduce the effect in
other laboratories. It has been noted that the most problem was the
manufacturing of a needed massive superconducting disk with a two-layer
specific structure. Our paper presents experimental results that we believe may
be related to the sought effect - similar inexplicable changes in weight have
been obtained for YBCO samples after they had been exposed to an alternating
magnetic field. The results, however, have been obtained in a different
experimental realization. Changes in weight are observed for the YBCO material
itself, which is in a non-superconducting state at room temperature but
exhibits slight diamagnetic properties. Instead of the complexly formed disc,
our material represents partially hydrated powder. In our case, values of the
inexplicable weight changes, which are well reproducible from sample to sample,
are about 0.01 wt. %.
