Nuvistor

Nuvistors were made to compete with the then-new bipolar junction transistors, and were much smaller than conventional tubes of the day, almost approaching the compactness of early discrete transistor casings.

Due to their small size, there was no space to include a vacuum fitting to evacuate the tube; instead, nuvistors were assembled and processed in a vacuum chamber by simple robotic devices.

[1] They have excellent VHF and UHF performance, and low noise figures, and were widely used throughout the 1960s for low-power applications in television sets (beginning with RCA's "New Vista" line of color sets in 1961 with the CTC-11 chassis), radio receivers and transmitters, audio equipment, and oscilloscopes.

It was also later found that, with minor circuit modification, the nuvistor made a sufficient replacement for the obsolete Telefunken VF14M tube, used in the Neumann U47 studio microphone.

[2] Tektronix used nuvistors in several of its high end oscilloscopes of the 1960s,[3] before replacing them later with solid-state JFETs.

Nuvistors were used in the Ranger space program and Russian-made ones (with soldered pigtail leads, more reliable than sockets)[1] were used in the Soviet MiG-25 fighter jet, presumably to radiation-harden the fighter's electronics; this was discovered following the defection of Viktor Belenko.