Dating siemans 12ax7


This 1950s Telefunken ECC83 / 12AX7 has long ribbed plates and a halo getter.

The white label on the glass has the Fisher logo and the diamond imprint is on the base.

The red print on the glass has the RCA logo (partial / missing). The green print on the glass reads "JAN 12AX7WA" (labels may be partial). The military spec Sylvania 12AX7 tubes in this precisely matched pair have gray plates with copper grid posts and halo getters.

The orange labels have the Amperex logo and the Blackburn, UK factory codes are etched in the glass. This 1976 Mullard ECC83 / 12AX7 tube has a halo getter and short gray plates (I63 series).

The white label has the Philips logo and the Blackburn, UK factory code is etched in the glass.

It has Mullard style short gray plates and a slanted halo getter.

The yellow print on the glass has the Raytheon logo. The 1970s Mullard 12AX7 / ECC83 tubes in this precisely matched pair have short gray plates and halo getters (I63 series).

The white labels on the glass have the Tung-Sol logo (partial).