Primax moving iron loudspeaker, 1924-1927
1924-1927
1924-1927
1980
1927-1930
1970-1985
1935-02-22
1935-1940
1938
25 June 1934
25 June 1934
1971
1970-1985
25 June 1934
25 June 1934
1968
1940
1932
1932
1960-1980
1970-1985
1940-1970
1960-1975
1980-1985
1986
1950-1970
1960-1970
1960-1970
circa 1955
mid-20th century
1964
1900-1951
1985
1970-1985
1940-1960
1940-1960
1970-1985