This part is a kind of semiconductor called ECC83.
Function of this product has Double Triode 1954.
Manufacturers : Philips
Image and pinout :

Some of the text within the PDF file :
page 1 2 3 4 5 6 7 8 9 10 11 ECC83 sheet 1 1 2 2 3 3 4 4 A B FP date 1954.11.11 1960.05.05 1954.11.11 1960.05.05 1955.02.02 1960.05.05 1955.02.02 1960.05.05 1953.06.06 1953.06.06 2005.05.06 [ ... ]
ECC83 PDF Datasheet Download
