Full three‐body calculations for the cross sections, vector analyzing powers, and tensor analyzing powers for radiative capture of polarized deuterons on protons over the energy range of available data are completed. The Paris, Bonn A, and AV14 two‐nucleon interactions are used by means of separable‐expansion methods. The Paris and Bonn interactions are handled by the Ernst‐Shakin‐Thaler (EST) method, whereas the AV14 potential is used through the new expansion of Koike, in order to reduce the two‐variable integral equations to a single variable. The electromagnetic transition is calculated with the Siegert long‐wavelength E1 operator. Comparisons are made between results for different nucleon‐nucleon interactions and with respect to the experimental data.