  Universal regularities of the Fourier spectrum of signal, generated by
complex analytic map at the period-tripling bifurcations accumulation point are
considered. The difference between intensities of the subharmonics at the
values of frequency corresponding to the neighbor hierarchical levels of the
spectrum is characterized by a constant $\gamma=21.9$ dB?, which is an analogue
of the known value $\gamma_F=13.4$ dB, intrinsic to the Feigenbaum critical
point. Data of the physical experiment, directed to the observation of the
spectrum at period-tripling accumulation point, are represented.
