
HF tester
circa 1960
circa 1960
1960
1961
1953
1951
1951
1960-1961
circa 1960
1960
1960
1953
1955
1960
2000-100 BCE
2000-1001 BCE
1958
2000-500
1956
1971-1900
1951
1960
circa 1960
circa 1960
circa 1960
1960
circa 1951
1955
1952-1953
1952
1952
1952
1952
1952
1952
1952
1959-1961
1960-1961
1957
1960
1956
1951
1953
1951
1953
1956
1959
1958
1960
1951
1956