Submerged repeater amplifier, 1967
1967
1967
1956
1954
1953
1955
circa 1939
1935
1910-1920
1965; 1965
1954-1960
2017
1952
1938
circa 1963
1900-1930
circa 1931
1963
1936
1972
circa 1943
1952
1938
1923-1925
circa 1949
1956
1961
1931
1919
1999
1970-1971
1931-1940
1960
1960
1976
1936
circa 1943
1968
1938
1976
1966-1974
circa 1965
1977