This month's ER has a story by Ray Osterwald comparing various tubes 6BZ6, 6DC6, 6GM6 (forgot the 6JD6 ?) for his SX-101A restoration, using a TV2 for evaluation. Leaves lots of unanswered questions though. I ought to take my metered "tube tester plus" and perform a similiar test at Drake 2B voltages. 73 Kees K5BCQ