The hearing for the purpose of taking evidence upon a complaint shall be conducted by an administrative law judge designated by the chief administrative law judge in Washington, DC, or by the associate chief judge, San Francisco, California, by the associate chief judge in New York, New York, or by the associate chief judge in Atlanta, Georgia, as the case may be, unless the Board or any member thereof presides. At any time an administrative law judge may be designated to take the place of the administrative law judge previously designated to conduct the hearing. Such hearing shall be public unless otherwise ordered by the Board or the administrative law judge. (49 Stat. 449; 29 U.S.C. 151-166, as amended by (61 Stat. 136; 29 U.S.C. Sup. 151-167), (65 Stat. 601; 29 U.S.C. 158, 159, 168), (73 Stat. 519; 29 U.S.C. 141-168), (88 Stat. 395-397; 29 U.S.C. 152, 158, 169, 183)) [45 FR 51193, Aug. 1, 1980, as amended at 62 FR 1668, Jan. 13, 1997]