We have studied the virgin curve and hysteresis of radio-frequency magnetoabsorption in ) and BSCCO () samples at 77 K in a magnetic field up to a value of 2 kOe. The hysteresis of YBCO - Ag is in good agreement with the prediction of the two-level critical state model. However, in the case of BSCCO the agreement is there only when the maximum field does not exceed 67.5 Oe for a frequency of 1.5 MHz. For higher fields the results resemble those of the one-level critical state model. This is due to the fact that at fields greater than 67.5 Oe the superconducting grain boundaries become normal. The cross-over point shifts to 55 Oe when the frequency is increased to 12 MHz. A qualitative explanation of this shift is given on the basis of the disordered model.