Short-lived isomer 83mKr with its discrete electron spectrum has ideal properties to be used in the crucial role of calibration source in low energy experiments like KATRIN or XENON. To ensure smooth long-term operation of these experiments, reliable routines for production of 83Rb, which decays to 83mKr, have to be developed. We describe the methods developed at the Nuclear Physics Institute of the Czech Academy of Sciences at Rez, where 83Rb sources are created for KATRIN predominantly via the reaction 84Kr(p,2n)83Rb by colliding accelerated protons with a target filled with natural krypton gas.