We believe these tubes to be experimental miniature glass pentode tubes, similar to 6AM6 or CV4014, specifically designed to withstand high vibration. They have special 7 pin bases unlike any other 7 pin bases, and metal screening around the tube. They are printed in white BRIMAR MADE IN ENGLAND SX6064/P with triangular T logo. Boxes are standard Brimar red and black printed SX 6064/P.
We believe these tubes to be experimental miniature glass pentode tubes, similar to 6AM6 or CV4014, specifically designed to withstand high vibration. They have special 7 pin bases unlike any other 7 pin bases, and metal screening around the tube. They are printed in white BRIMAR MADE IN ENGLAND SX6064/P with triangular T logo. Boxes are standard Brimar red and black printed SX 6064/P.