For sale is a set of 4 vacuum tubes test good on our calibrated Jackson 648A tube tester:

tubes might be metal or glass GT depending what we have.  You get

6SA7GT/6SA7

6AC7 / 6SK7 / 6SK7GT

6SQ7/6SQ7GT

6F6 / 6F6GT / 6V6 / 6V6GT / 6n6c

solid state 5Y3 / 5U4 (its also a plug in replacement for 5Z4 5V4)

6sq7 tests ok but not as strong as others