Analysis of the AC and mechanical losses of PF RF ITER SULTAN sample test results has been performed. Measurements were provided by the gas flow colorimetric method before and after cyclic mechanical loads. The mechanical loss investigation was carried out for the virgin sample and after 10, 400 and 1000 cycles. Mechanical loss, as it was expected, decreased significantly after first ten cycles, but remains almost the same after the subsequent cycling. The value of mechanical loss even of the virgin sample does not affect strongly the workability of a magnet. AC loss measurements were carried out at different operating current in conductor, at background magnetic field of 2 T and 4.5 T before and after cycling. AC loss of all tested samples were practically the same before and after cycling, but strongly depended on a background magnetic field. As example, at zero operating current in conductor and variable magnet field frequency 6 Hz the AC loss decreased in ~1.4 times at background magnetic field of 4.5 T compare with loss at 2.0 T. An attempt to explain the phenomena has been done. The results of calculation and experimental investigation are presented.