A novel source of polarized hydrogen and deuterium molecules has been tested. The use of sextupole superconducting magnets allows us to select molecules with the nuclear spin projection -1 for hydrogen and -2 for deuterium. The measured beam intensity of polarized hydrogen molecules for the nozzle temperature range of 6.5 – 30 K and a gas flow rate up to 6.6∙10^-2 mbar∙l/s is presented. The measured flux of polarized hydrogen molecules of ~ 3 ∙10^12 mol/s is in reasonable agreement with the Monte-Carlo simulation. The obtained results can be used as a basis for the development of a high-intensity source of polarized molecules.