EN
Temperature dependences of the dielectric permittivity were studied for the ferroelectric K_{1-x}(NH_4)_xH_2PO_4 mixed crystal. The experiments revealed presence of the beginning of the dipolar glass - embryos in the concentration of ammonium x=0.095. Observations of the dielectric relaxations show much bigger effect domain mechanism than the one related to the growth of clusters of the dipolar glass.