NOTE: This answer relates to a rule proposed by REC and does not reflect current regulations in effect:
We look at the translators ERP (ERP to the farthest lobe on directional translators) and the height above average terrain based on 8 radials. The "sub-class" each translator is placed in is based on the curves calculation of the ERP and HAAT combination to the 60 dBu service F(50,50) contour.
Translator Reform