The 6211 is a special quality double triode designed for industrial and instrument applications where a long life with stable characteristics are required. The valve maintains emission when operated for prolonged periods at cut-off as in computer circuits.
The mechanical design is such as to prevent damage in areas of shock and/or vibration.
The anode plates are stitched together. The top mica is a double sheet - vibration protection.
The triode pair and a repeat of the Type designation.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins is 48 mm tall.
Reference: Data-sheet. Type 6211 was first introduced in 1960. See also1960 adverts.
