TUBE CODES


Hi,
I have some GeAt7 tubes,they are marked 58-39,58-17,4-39 and 5-22,does anyone know what these numbers mean?
128x128yogiboy

Showing 1 response by almarg

The 58-39 most likely means that the tube was manufactured in the 39th week of 1958. Likewise for 58-17. Not sure about 4-39 and 5-22, but perhaps the last two digits of those numbers also refer to the week, and the 4 and 5 also refer to the year, but with the first digit of the particular decade omitted.

Regards,
-- Al