Tube base type through decades

Noval base B9A 1957

Rimlock base B8A Europe 1948

Miniatur 7pin base B7G USA 1946

Loctal-8 base B8G USA 1938

German Steel base Y8A 1938

Europe side contact base P (P8A) 1936

Octal base K8A USA 1935

5pin base UY USA 1927 

6pin base U6A USA 1936