Okay, if you loose 3 Db, from 50 watts your erp is 25 watts.  Since 3 db =
25 watts, 1 db is a positive 1/3 over 25 watts. 1 times 25/3 equals 8.3
wqatts.  25 watts plus 8.3 wats equals 33.3333333 watts.  I rounded off the
third but you get the idea.

Howard