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Nuvistor bottom.jpg

Nuvistors are miniature, rugged, metal-ceramic enclosed vacuum tubes introduced by RCA in 1959 (first being the 7586). There are used in many Tektronix products of the 1960s.

As high-impedance buffers (cathode follower), Nuvistors were replaced by JFETs. As voltage amplifiers, they were mostly replaced by BJTs. Some products such as the 1A1 and 453 started production with Nuvistors and then later switched to transistors.

Nuvistors, like all tubes, eventually need to be replaced. They are no longer manufactured but they are still available online from old stock.

Another repair option is to convert the circuit to use a transistor. In at least one case (the 422), JFETs can be plugged directly into the Nuvistor sockets with no further circuit modification, and proper function of the scope is restored.



Nuvistors used in Tek gear include:

Page Class Manufacturer Model Part nos Description Used in Designers
6CW4 Vacuum Tube (Triode) 6CW4 154-0323-00 Nuvistor triode 1A7 3A8 3B2 6R1
7586 Vacuum Tube (Triode) 7586 154-0306-00 Nuvistor triode 1A1 1A2 1A5 10A2 10A2A 11B1 11B2A M 321 321A 3A74 3T77 6R1A 3A1 3A3 3A5 3A6 3A8 3A74 3S76 3T77A 4S1 6R1 82 86
7587 Vacuum Tube (Tetrode) 7587 154-0465-00 sharp-cutoff Nuvistor tetrode 184
7895 Vacuum Tube (Triode) 7895 154-0378-00 Nuvistor triode 3B1 3B3
8056 Vacuum Tube (Triode) 8056 154-0417-00 low-voltage Nuvistor triode 422 502 W 1S1 3A7 3S3 3T4 5T3 10A1
8393 Vacuum Tube (Triode) 8393 154-0461-00 Nuvistor triode 453 454 1A6 1A7 503