We obtained the spectrum of probability of the bremsstrahlung emission accompanying the α-decay of Ra (Eα=4.8 MeV) by measuring the α-γ coincidences and using the model presented in our previous study on the α−decay of Po (Eα=7.7 MeV). We compare the experimental data with the quantum mechanical calculation and find a good agreement between theory and experiment. We discuss the differences between the photon spectra connected with the α-decay of the Ra and Po nuclei. For the two mentioned nuclei we analyze the bremsstrahlung emission contributions from the tunneling and external regions of the nucleus barrier into the total spectrum, and we find the destructive interference between these contributions. We also find that the emission of photons during tunneling of the α-particle gives an important contribution to the bremsstrahlung spectrum in the whole Eγ energy range of the studied Ra nucleus.