This post provides examples of Raytheon manufactured tubes.
Raytheon was an extremely high quality USA tube manufacturer with prolific output, covering both civilian issue and a vast majority of US Military parts production. The Raytheon (EIA) code number is “280″.
Here is an example:
In this photo, we see three Raytheon-manufactured 6SN7GT tubes featuring Black Plates, square getters, clear tops, and dual plate support rods. You can see the 280 EIA code on each tube base, and the identical design.
Notice that the middle tube has the Admiral retail name. Some people mistakenly think that all Admiral tubes were made by GE. That is wrong. While most Admiral tubes were GE manufactured, here you see an example of Raytheon production.