(!!!!) (Best Overall Quad) 6106 Bendix 1950's rebranded 5Y3WGTA Heintz & Kaufman NOS (matched quad) 1-2% matched

1 matched quad) 6106 Bendix NOS 1950's rebranded "5Y3WGTA Heintz and Kaufman" in H & K boxes 1970's double "D" getter halos

1 tube) 66/40 and 68/40

1 tube) 66/40 and 68/40

1 tube) 67/40 and 68/40

1 tube) 67/40 and 68/40 

6106 is a indirectly heated (slow warmup; 30-45 seconds) sub for a 5Y3GT

5Y3GT has a directly heated filament