  Within the modified model of proton ordering of one-dimensional ferroelectric
having hydrogen bonds of PbHPO$_4$-type, their thermodynamic and dynamic
characteristics are studied and calculated taking into account the linear (by
crystal deformations $\varepsilon_i$ ($i=1,3$) and $\varepsilon_4$)
contributions into the energy of a proton system but without taking into
account the tunneling in the two-particle cluster approximation. There has been
obtained a good quantitative description of the temperature dependence of
polarization, static dielectric permittivity, heat capacity and frequency
dependence of dynamic dielectric permittivity at different temperatures for
PbHPO$_4$ and PbHDO$_4$ crystals.
