The nuvistor is a type of vacuum tube announced by RCA in 1959. 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. The tube envelope is made of metal, with a ceramic base. Triodes and a few tetrodes and pentodes were made; nuvistor tetrodes were taller than triodes.
Nuvistors are among the highest-performing small-signal radio-frequency receiving tubes, largely due to low stray capacitance and inductance due to their small size.[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. RCA discontinued their use in television tuners in late 1971.
Nuvistor applications included the Ampex MR-70, a studio tape recorder whose entire electronics section was based on nuvistors, and studio-grade microphones from that era, such as the AKG/Norelco C12a, which employed the 7586. 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