The equation for the maximum working bank and coordination level, dependent on the electrical size of some ideal according to the Chu and Harrington criteria antenna is reduced. The characteristics of coordination is assumed to be rectangular and the contact ration can be arbitrary. The received equation expresses the limit of the Chu–Harrington limit for the relative line, coordination level and electrical size of the radiator. The results of computing dependent on the contact ration and electrical size are given as charts and tables.