Application of the two-zone model to the FSRQ 3C273, focusing on the high-energy spectral range. The acceleration zone is located at z = 0.01 pc, with a magnetic field strength of B = 1 G and radius R_I = 5 × 10¹⁵ cm, the cooling zone is one order of magnitude more distant and larger than the acceleration zone. The external photon field arises from isotropic scattering of disk photons on wind particles between radii R₁ = 9 × 10¹⁴ cm and R₂ = 3 × 10¹⁸ cm, with energy density U_ext = 2.5 × 10⁻³ erg cm⁻³. The bulk Lorentz factor is Γ = 30, the Doppler factor is δ = 15, and the characteristic disk temperature is T_disk = 3 × 10⁴ K. The observational data are from Giommi et al. (2012).