Fact-checked by Grok 2 weeks ago

Nuvistor

The nuvistor is a miniature, rugged vacuum tube constructed with a metal-ceramic enclosure, developed by the Radio Corporation of America (RCA) and first announced in 1959 as a high-performance alternative to both conventional vacuum tubes and emerging transistors. The inaugural model, the 7586 triode, exemplified its compact design—measuring approximately 20 mm in height and 11 mm in diameter—while offering low inter-electrode capacitance, high transconductance, and operation on a low-power 6.3 V heater. Nuvistors emerged during the late 1950s transition from to , positioning them as a bridge to address the limitations of early bipolar junction transistors, such as and overload handling. RCA promoted the nuvistor as "the tube of tomorrow," leveraging advanced manufacturing techniques like assembly and cantilever-supported electrodes to achieve unprecedented and reliability. By , they featured prominently in RCA's New Vista color televisions, and production continued into the early 1970s before transistors fully supplanted them in most consumer applications. Despite their short commercial lifespan, millions of nuvistors were produced for diverse uses, with some models like the 7586 demonstrating failure rates as low as 0.099% per 1,000 hours. The nuvistor's innovative design included a cylindrical arrangement within a sealed metal and base, often using a 12-pin "Twelvar" socket for easy integration into transistor-like circuits. This construction minimized microphony, enhanced high-frequency performance up to 1.2 GHz in certain variants like the 8627, and provided superior durability against shocks up to 1,000 g and nuclear radiation exposure without permanent damage. Compared to transistors, nuvistors excelled in low-noise amplification for high-impedance sources (over 500 Ω), such as antennas or vidicon , and tolerated momentary overloads better while operating at higher voltages. Available primarily as triodes (e.g., 6CW4, 7586) and s (e.g., 7587), they consumed under 1 W of heater power, making them suitable for battery-operated and space-constrained devices. Nuvistors found widespread adoption in VHF/UHF television tuners, professional audio equipment like AKG C12a microphones and MR-70 tape recorders, and military systems including sonobuoys and in Soviet MiG-25 . They powered RF/IF amplifiers, mixers, and audio preamplifiers in broadcast radios, tuners (e.g., Sansui TU-70), and even NASA's spacecraft and satellites. In test equipment, such as oscilloscopes (e.g., models 453 and 1A1), they served as high-impedance buffers until replaced by JFETs in later revisions. Though no longer manufactured, new-old-stock nuvistors remain prized in vintage audio restoration and niche high-fidelity applications for their warm and low .

History

Invention and Announcement

The nuvistor was invented by engineers at the in the late as a compact designed to address the limitations of earlier tube technologies amid the rising prominence of solid-state devices. Development focused on miniaturization and improved performance, resulting in a thimble-sized structure that marked a significant in design. RCA officially announced the nuvistor on March 23, 1959, positioning it as a high-performance alternative to the emerging bipolar junction transistors, particularly in applications requiring low noise and operation at elevated temperatures. The device was heralded for rivaling transistors in size while surpassing them in certain high-frequency capabilities, serving as a transitional technology during the waning years of the era. This announcement came at a pivotal moment when semiconductors were beginning to dominate electronics, with the nuvistor intended to bridge the gap by combining tube reliability with compact, rugged construction. The first nuvistor type released was the 7586 , a medium-μ general-purpose optimized for high-gain, low-noise in VHF and UHF applications up to 400 MHz. As the inaugural prototype, the 7586 exemplified 's innovative approach, enabling its use in demanding environments like tuners and early high-frequency circuits.

Production Era and Manufacturers

The nuvistor entered commercial production in 1959 following its announcement by , marking the beginning of a brief but significant era in manufacturing that lasted primarily through the . established itself as the dominant producer, leveraging its expertise in electron technology to fabricate these miniature, all-metal-ceramic devices at facilities including those in , and later , where nuvistor assets were relocated to support ongoing output. By July 1961, had already achieved production volumes exceeding one million units, reflecting rapid scaling to meet demand in and industrial applications. Production peaked during the mid-1960s, with conducting extensive life testing on models like the 7586, accumulating over 1.66 million tube-hours of data from regular manufacturing runs, which underscored the reliability and uniformity of output at scale. Estimates indicate manufactured several million nuvistors in total during this period, driven by contracts for television tuners, test equipment, and military systems where high-frequency performance was essential. While was the dominant U.S. producer, other American companies including , Sylvania, and also manufactured nuvistors. licensed designs to select European firms, including (a subsidiary) in the UK and in , enabling limited manufacturing abroad to serve regional markets. These licensees produced compatible types, such as the 7586, but output remained far smaller than 's. By the early , nuvistor production began a sharp decline as silicon transistors and integrated circuits surpassed tubes in cost, size, and reliability for most applications, leading to phase out dedicated lines. Military-spec variants persisted under government contracts into the mid-to-late , but commercial manufacturing largely ceased by the decade's end, with remaining stock from surplus inventories supporting repairs and niche uses through the . This shift aligned with the broader contraction of U.S. industry, where total annual output fell from peaks of over 100 million units in the 1950s to under two million by 1974.

Design and Construction

Physical Structure

The nuvistor features a compact cylindrical , typically measuring approximately 0.44 inches (11 mm) in and 0.8 inches (20 mm) in length, making it significantly smaller than a traditional and enabling its use in miniature electronic devices. This diminutive form factor was a key innovation, allowing the tube to fit into tight spaces such as television tuners and portable equipment while maintaining robust performance. The enclosure consists of an all--and-metal construction, providing hermetic sealing to maintain the necessary for flow and offering exceptional resistance to and . The metal shell, often equipped with two peripheral lugs of unequal width for precise indexing and orientation, encases the internal components, while the elements ensure thermal stability and durability under harsh environmental conditions. This rugged design contributed to the nuvistor's suitability for and applications, where reliability in extreme scenarios was paramount. Internally, the electrodes are arranged in a , cantilever-supported cylindrical configuration, with the , , and aligned in a straight-line to minimize lead and inter-electrode . This layout, supported directly by leads extending through the base, eliminates the need for traditional spacers, enhancing mechanical integrity and reducing parasitic effects for high-frequency operation. The base employs the characteristic 12-pin Twelvar configuration, where pins protrude through a wafer to connect the heater and electrodes, though variations exist for specialized types such as double-ended or variants with additional contacts or top caps. These pins are arranged in concentric circles for with dedicated sockets, ensuring secure mounting and electrical in compact circuits.

Materials and Internal Components

Nuvistors feature an all-metal-and- construction, utilizing a cylindrical metal shell typically made from durable alloys such as , combined with a base wafer for the enclosure. This design eliminates envelopes entirely, providing enhanced thermal conductivity and structural rigidity compared to traditional tubes. The components, often alumina-based, serve as insulators and bases, enabling reliable seals that maintain integrity under high temperatures. The internal electrodes consist of lightweight, cantilever-supported cylindrical structures arranged coaxially for optimal electron flow. The is constructed from coated with emissive oxides to facilitate at lower operating temperatures, while the grid employs fine wires wound in a helical to achieve close spacing for high and low . The is typically formed from nickel-plated metal to handle heat dissipation effectively. These electrodes are brazed together in precision jigs without spacers, ensuring a strain-free assembly that minimizes and supports high-frequency operation. A high vacuum, on the order of 10^{-8} , is achieved through high-temperature processing at around 850°C during fabrication, resulting in an exceptionally internal environment without the need for getters in many designs. This processing cycle, lasting about 10 minutes in a , expels residual gases and contaminants, contributing to the tube's long life and low noise characteristics. of a typical nuvistor , such as the 7586, reveals the intricate internal layout: the central heater filament surrounded by the oxide-coated cathode sleeve, encircled by the tightly wound helical supported by its lead connections, and the outer nickel-plated cylinder. The assembly terminates in metal- seals at the base, with pins extending through the ceramic disc for external connections; cross-sectional views from de-capped samples highlight the absence of supporting discs and the rigid, end-supported structure that enhances mechanical stability.

Electrical Characteristics

Pin Configurations

Nuvistors utilize a 12-pin Twelvar base conforming to standard E5-65 for the active pins, featuring a circular arrangement of pins numbered clockwise from the bottom view starting at pin 1, adjacent to a large indexing lug for alignment. The base includes 5 long pins for external connections (plate, , , heater) and 7 short pins that are internally connected or unused to support the structure and minimize inductance. For standard types such as the 7586 and 7895, the key connections are pin 2 to the plate (), pin 4 to the , pin 8 to the , and pins 10 and 12 to the heater, with pins 1, 3, 5, 6, and 7 typically shorted internally to the . Variations in pin usage occur across types to optimize performance; for instance, the 8058 employs multiple pins (1, 3, 5, 6, 7) shorted to the for low-inductance paths, pin 4 for , pins 10 and 12 for the heater, and a (JEDEC C1-44) for the plate connection. In standard configurations, such as the 7586, short pins connect to internal structures within the metal to reduce external interference. Military-grade nuvistors, like the JAN-7586, may incorporate locked or reinforced pins for enhanced durability in rugged environments. Base diagrams commonly depict a bottom view illustrating the pins in a concentric circle pattern, with the large lug positioned near pin 1 and a small lug near pin 6 for , alongside side profiles that emphasize the compact 0.5-inch and short pin lengths (approximately 0.2 inches) to facilitate high-frequency . These views highlight the even spacing at 30-degree intervals for the 12 pins, ensuring mechanical stability. The pin layout is engineered for insertion into specialized 5-contact sockets with an annular groove to engage the lugs, promoting reliable connectivity despite the tube's diminutive size, which demands precise alignment during installation to prevent pin misalignment or bending.

Operating Principles and Parameters

Nuvistors function as triode tubes, relying on for flow within their metal-ceramic . An oxide-coated serves as the source, heated indirectly by an embedded to liberate s into the interelectrode space. These s form a space-charge cloud that is modulated by a negatively biased , which regulates the beam's intensity before collection at the positively charged (plate), enabling of input signals applied to the grid. variants, such as the 7587, incorporate an additional screen grid between the control grid and plate to enhance in RF applications. The heater, typically operating at 6.3 volts or with a current draw of 0.15 to 0.3 amperes, maintains the at an emission temperature suitable for stable operation; low-voltage variants, such as the 2CW4, use 2 volts at 0.45 amperes for specialized battery-powered applications. Plate supply voltages range from 100 to 250 volts, supporting typical operating currents of 5 to 10 milliamperes, while values of 5 to 10 milliamperes per volt ensure effective signal amplification. Interelectrode capacitances are minimized to less than 1 picofarad for key paths like grid-to-plate, reducing parasitic effects in high-frequency circuits. Nuvistors exhibit a broad , with cutoff frequencies exceeding 500 megahertz attributable to their low lead inductance and symmetric cylindrical structure, allowing effective performance up to very high frequencies (VHF) and into ultra-high frequencies (UHF). At VHF bands, noise figures below 2 decibels are achievable under matched conditions, making them suitable for sensitive front-ends. The amplification factor, or mu (μ), in nuvistor triodes is determined by the relation μ = g_m × r_a, where g_m denotes transconductance and r_a the anode (plate) resistance; typical values range from 20 to 50, varying by type—for instance, the 7586 medium-mu triode achieves around 35, while high-mu types like the 7895 reach 64.

Types and Variants

Standard Triode Types

The standard triode nuvistors were developed primarily for consumer applications in radio and equipment, where their compact size, low , and high-frequency capabilities made them suitable for RF and IF amplification stages in tuners and receivers. The 7586, the first nuvistor type announced in 1959 by , served as a medium-mu optimized for RF . It delivers a typical of 11 mA/V under standard operating conditions, enabling high gain with low in circuits up to 400 MHz, and found widespread use in tuners. The 6CW4 represents a low-noise variant designed specifically for and VHF receiver front ends, featuring a 6.3 V heater and operational capability extending to frequencies around 900 MHz for RF amplification in grounded-cathode configurations. The 7895 is a high-mu, high-slope with a of 9.4 mA/V, tailored for intermediate-frequency (IF) amplifiers requiring elevated gain and stability up to 400 MHz. Low-voltage heater variants of consumer , such as the 2DS4 (2.1 V heater) and 6DS4 (6.3 V heater), provided semi-remote cut-off characteristics for VHF applications in battery-powered home-entertainment gear. The 13CW4 offered performance similar to the 6CW4 in a configuration, utilizing a 13.5 V heater at 0.06 A for applications like boosters. All standard types employ a 5-pin ceramic-wafer base ( E5-65), share nearly identical cylindrical metal envelopes measuring approximately 11 mm in diameter and 20 mm in height, and are engineered for low power dissipation (heater current around 0.135 A) while supporting high-frequency performance with minimal interelectrode .

Specialized and Military Variants

Specialized nuvistor variants were developed to withstand harsh environments, including high , , and , making them suitable for and applications requiring enhanced durability. The 8058, a double-ended high-mu , features reinforced ceramic-metal construction that enables it to endure 500g mechanical and 1g , with mechanically modified internal structures for vibration-prone uses such as oscillators and cathode-drive RF amplifiers operating up to 1200 MHz. Its all-metal-and-ceramic envelope provides isolation between input and output circuits, and it maintains performance with a 6.3 V heater at 0.135 A, achieving a typical of 12,400 µmhos. Military-specification nuvistors, such as the 7586A, adhered to standards like MIL-E-1/1397A, ensuring reliability under severe conditions including up to 1000g, at 2.5g, and exposure to nuclear radiation with less than 1% change in after 10.8 × 10¹⁶ neutrons/cm². This medium-mu delivers high and low up to 400 MHz, with a projected life exceeding 10,000 hours based on life tests showing a 0.475% per 1000 hours at 95% confidence.

Tetrode Variants

Nuvistor tetrodes, such as the 7587 and 8627, extended the device's capabilities for high-frequency applications. The 7587 is a high-frequency suitable for RF amplifiers and oscillators up to 900 MHz, featuring a 6.3 V heater and low interelectrode . The 8627, a rugged variant, operates up to 1.2 GHz with enhanced durability for uses, including a of approximately 7 mA/V.

Applications

Consumer and Broadcast Uses

Nuvistors found significant application in the VHF and UHF front-ends of television tuners during the early , particularly in sets where their low noise figures and high gain were essential for reliable signal reception in fringe areas. pioneered this use starting with the CTC-11 in their 1961 "New Vista" line of color televisions, employing the 6CW4 nuvistor as the RF alongside conventional like the 6EA8 oscillator-mixer. This configuration provided superior performance over earlier miniature , with the nuvistor's compact size and low inter-electrode capacitance enabling efficient handling of high-frequency signals up to UHF bands. The design persisted in sets for approximately a decade until solid-state alternatives dominated by the early . In high-fidelity FM radio receivers, nuvistors enhanced RF stages by offering improved sensitivity compared to subminiature tubes such as the 6ER5 or 6FH5. Manufacturers like H.H. Scott integrated the 6CW4 nuvistor into tuner front-ends, utilizing configurations for broadcast reception that delivered and stability across wide temperature ranges, from -190°C to 350°C. Similarly, the Harman-Kardon III tuner from featured a nuvistor in its front-end to achieve low noise and exceptional sensitivity, supporting professional-grade audio quality in home systems. By the mid-1960s, nuvistors had reached peak adoption in home entertainment devices, appearing in millions of and radio units as a transitional technology in tube-transistor circuits that combined RF performance with emerging solid-state amplification. These optimized sensitivity and reliability in , with examples like H.H. Scott tuners leveraging the 6CW4 for superior broadcast reception in high-fidelity setups. This era marked nuvistors' role as a bridge between and eras in everyday .

Industrial and Instrumentation Applications

Nuvistors found significant application in oscilloscopes, particularly in high-performance models from , where their low-noise and fast-response characteristics were essential for precise signal . In the 500-series oscilloscopes, the 7586 nuvistor was employed in vertical plug-ins such as the 1A2, 3A3, and 2A61, enabling bandwidths up to 50 MHz at higher sensitivity settings while maintaining low distortion and high gain. This integration allowed for reliable operation in laboratory and engineering environments requiring accurate waveform display without the microphony issues common in earlier vacuum tubes. In military contexts, nuvistors were valued for their rugged construction, including resistance to shock up to 1000 g and vibration, making them suitable for expendable and harsh-environment gear. They were incorporated into sonobuoys for underwater submarine detection, where types like the RCA 8382, 8441, and 8456 triodes, along with the 8380 tetrode, provided low-power RF amplification to extend battery life—often tested for 20- to 100-hour reliability under simulated deployment conditions. The 2DS4 nuvistor, a compact triode variant, supported similar expendable applications in detection systems due to its mechanical stability and low power draw. In avionics, nuvistors enhanced vibration-resistant front-end amplifiers for radar and communication systems, as seen in prototypes like the Marconi Clansman 353 military radio, where their small size and durability minimized failure rates in airborne operations. For industrial and medical instrumentation, nuvistors served as low-noise preamplifiers in and test equipment, leveraging their high and minimal noise figures for sensitive . Test equipment like the 3400A True utilized nuvistors in the front-end for low-noise RF amplification up to VHF frequencies, ensuring accurate measurements in industrial calibration setups. RCA secured military contracts in the 1960s to integrate nuvistors into front-ends, where types like the 7587 and 8058 delivered high-gain, low-noise performance up to 1.2 GHz in RF and mixer stages for detection systems. These deployments highlighted nuvistors' role in professional tools demanding reliability under extreme conditions, from vibration-heavy to scientific instruments.

Advantages and Limitations

Performance Advantages

Nuvistors exhibited superior ruggedness compared to conventional vacuum tubes, primarily due to their all-metal-and-ceramic , which minimized fragility and enabled operation in harsh environments. They could withstand mechanical shocks up to 3000 for 1 minute sustained duration, exceeding the 1000 0.8 ms pulse standard for specifications (MIL-E-1E) and outperforming typical tubes that were prone to breakage under far lesser forces. This durability, combined with their compact size—weighing approximately 1.9 to 2.4 and measuring less than 1.4 inches in diameter—facilitated the design of smaller, more reliable equipment without sacrificing performance. In terms of radio-frequency (RF) performance, nuvistors provided exceptional characteristics that surpassed early transistors, particularly at ultra-high frequencies (UHF) until the 1970s. Their interelectrode capacitance was remarkably low, typically under 0.5 pF (e.g., grid-to-plate in the 7587 type), reducing stray effects and enabling high gain-bandwidth products up to 148 MHz—superior to comparable tubes like the 6AK5 (71 MHz). Noise figures were also minimized at less than 1.5 dB (optimized at 200 MHz for types like the 7586), offering better low-level amplification for weak RF signals than contemporary transistors with high-resistance sources. Nuvistors demonstrated extended longevity and efficiency, with operational lives exceeding under typical conditions, as evidenced by life tests on the 7586 type yielding a of 0.475% per 1,000 hours. Their low heater power consumption, around 0.9 W (e.g., 6.3 V at 0.135 A for the 7586), operated at reduced temperatures (1150–1350°K versus 1500–1700°K for standard ), which not only prolonged life but also made them suitable for battery-powered applications. The design of nuvistors facilitated their integration into hybrid circuits, bridging the transition from vacuum tubes to solid-state devices by combining tube advantages like low with efficiency in mixed-signal systems. For instance, types like the 8056 operated effectively at low plate voltages (12–50 V) with high , allowing seamless pairing with transistors in applications such as spacecraft electronics.

Key Limitations and Decline

Despite their innovative design, nuvistors suffered from significant , where mechanical vibrations induced electrical noise due to the tight spacing of the cantilevered grid and other electrodes supported only at the base without top bracing. This sensitivity proved particularly problematic in audio applications, such as experimental modifications to U47 microphones, where vibrations from handling or sound waves caused audible artifacts and reduced performance. Nuvistors also required higher power consumption than contemporary transistors, with typical total dissipation around 1-2 watts including the heater at under 1 watt and voltages of 70-100 volts, limiting their efficiency in battery-powered or low-power devices. Manufacturing costs were elevated due to the precision fabrication of ceramic-metal envelopes and assemblies in chambers, making nuvistors more expensive than standard vacuum tubes or emerging alternatives. The decline of nuvistors accelerated in the 1970s as silicon RF transistors, such as improved bipolar junction types, achieved comparable noise figures (e.g., 1.3 at 1 GHz) and at VHF/UHF frequencies while offering lower cost and greater integration. By the early 1980s, these advancements rendered nuvistors obsolete in most applications, with ceasing production around 1976-1978 after transferring assets to Sylvania. Environmentally, nuvistors were fragile to conditions, which could damage the delicate structures more readily than ruggedized transistors, and exhibited shorter operational life in high-heat environments despite their low-temperature "dark heaters" operating 350 cooler than conventional filaments.

References

  1. [1]
    [PDF] Radio Corporation of America
    Since RCA nuvistor tubes were first announced in. 1959, they have been used in a wide variety of con sumer, industrial, and military equipment. Millions of.
  2. [2]
    Nuvistor Valves - The Valve Museum
    Introduction of the Nuvistor. RCA announced the first Nuvistor triode valve, the 7586, in 1959. Modern folk law has the initial intended application as TV VHF/ ...
  3. [3]
    Nuvistor - TekWiki
    Oct 8, 2025 · Nuvistors are miniature, rugged, metal-ceramic enclosed vacuum tubes introduced by RCA in 1959 (first being the 7586). They are used in many Tektronix products ...
  4. [4]
    Retrotechtacular: Nuvistor, Vacuum's Last Gasp | Hackaday
    Jul 21, 2021 · A fascinating device from the end of the vacuum tube era, they were some of the smallest high-frequency vacuum devices ever created.
  5. [5]
    [PDF] RCA Nuvistor Tubes - World Radio History
    Because the nuvistor tube contains no glass or mica components, has a short low-mass structure, and is processed at very high temperatures, it is capable of ...
  6. [6]
    Tiny Vacuum Tube Rivals Transistor, May 1959 Electronics World
    Jul 11, 2018 · The RCA Nuvistor was a godsend to hardline vacuum tube lovers who were steadfast members of the Never Transistor movement of the 1950s and 1960s.
  7. [7]
    GOODS & SERVICES: New Ideas, Mar. 23, 1959 - Time Magazine
    RCA said the thimble-sized “Nuvistor” tube outperforms regular tubes and transistors in higher frequencies and at higher operating temperatures. When ...Missing: details | Show results with:details
  8. [8]
    R.C.A. Introduces a Tiny Tube; Terms Device Better Than ...
    R. C. A. has said that performance by the Nuvistor excelled that for much larger vacuum tubes and transistors when low electrical voltage was needed. The ...<|control11|><|separator|>
  9. [9]
    7586 - The Valve Museum
    The 7586 was the first production Nuvistor type and was introduced in 1959. The Nuvistor from RCA was a form of triode for use at VHF and built into a metal ...
  10. [10]
    [PDF] RCA nuvistor - Frank's electron Tube Data sheets
    BASIC NUVISTOR CONCEPT. Since RCA nuvistor tubes were first announced in. 1959, they have been used in a wide variety of con-.
  11. [11]
    RCA Early Transistor Oral History Mendelson Page 8 Nuvistors and ...
    By 1962, Nuvistor technology had become quite mature and RCA claimed production quantities of 1,000,000 as early as July 1961. Most of these unique tubes were ...Missing: timeline | Show results with:timeline
  12. [12]
    [PDF] History of Vacuum Tube Manufacturing in the US From WWII to the ...
    • GE and Westinghouse manufacture equipment sold by RCA. • Purpose: Free ... tube designs. • The Nuvistor assets were moved to Emporium, PA. • The 60 ...Missing: timeline | Show results with:timeline
  13. [13]
    [PDF] RCA Nuvistors - World Radio History
    Type 7586 nuvistor tubes have been operated, for 3 hours ... Nuvistor Triode. Typical Double-Ended. Nuvi stor Tetrode. Typical Double-Ended. Nuvistor Triode.
  14. [14]
    [PDF] RCA-7895 - Dr.Tube
    RCA-7895 is a high-mu nuvistor triode of the heater-cathode type designed for use in a wide variety of applications in industrial equipment where.
  15. [15]
    [PDF] RCA Nuvistors - Frank's electron Tube Data sheets
    Based on over 1,662,000 tube-hours of regular-production life tests, nuvistor ... 1CE-280 RCA Nuvistor Tubes for Industrial and Military. Applications ...Missing: quantities | Show results with:quantities
  16. [16]
    [PDF] 6CW4 - Dr.Tube
    DATA I. Harrison, N. J.. 1-63. Page 2. 6CW4. Basing Designation for BOTTOM VIEW. Pin 1ª - Do Not Use. Pin 2 - Plate. Pin 3 - Same as Pin 1.Missing: count | Show results with:count
  17. [17]
    [PDF] High-Efficiency Thimble-Size Electron Tubes Made Possible by RCA ...
    Nuvistor tubes are made of ceramic materials and strong metals such as steel, molybdenum, and tungsten. "The electrodes are strongly supported from one end in ...
  18. [18]
    [PDF] for Industrial and Military Applications - Bitsavers.org
    The nuvistor design, developed by. RCA, utilizes a light-weight, cantilever- supported, cylindrical electrode struc- ture housed in an all-ceramic-and-metal.Missing: computer optimization
  19. [19]
    An Experiment on Thermionic Emission Using a Nuvistor Triode
    Oct 1, 1974 · A 6CW4 nuvistor triode is used in an experiment which deals with the following aspects of thermionic emission: verification of the assumption ...
  20. [20]
    Random objects: the nuvistor - lcamtuf's thing - Substack
    Oct 28, 2022 · This subminiature vacuum tube had a form factor similar to the early transistors. It ditched the fragile and bulky glass enclosure for a metal can with a ...
  21. [21]
    [PDF] Nuvistor Tubes
    advantages of the RCA dark heater include. (1) substantially less change in heater shape, which greatly reduces the possi- bility of heater damage and heater ...
  22. [22]
    [PDF] Print RCA_7895.TIF (10 pages)
    PIN 1: METAL. SHELL. DIMENSIONAL OUTLINE. -.400″MAX. DIA.- .200" MIN. DIA. FLAT. BASE. JEDEC Nº E5-65 .100" MIN. .130" MAX. 5 PINS .016"±.001" DIA. .435”MAX.
  23. [23]
    [PDF] 8393
    NUVISTOR TYPE. For Industrial Applications. GENERAL DATA. Heater ... 133 65 10 001, or equivalent. Base.. Medium Ceramic-Wafer Twelvar 5-Pin (JEDEC No.
  24. [24]
    The Nuvistor - The Valve Page
    Sep 17, 2001 · This is either a triode or tetrode valve of special design, which in the past was of Americah origin, under the designation 6CW4.
  25. [25]
    7586 - TekWiki
    Jul 5, 2025 · The 7586 (P/N 154-0306-00) is a Nuvistor triode vacuum tube, introduced in 1959 as the first tube of the series.
  26. [26]
    https://w140.com/tekwiki/wiki/7586
  27. [27]
    https://www.rfparts.com/6cw4-rca.html
  28. [28]
    [PDF] 7586
    for RCA Nuvistor Tubes at front of this Section. Medium Ceramic-Wafer Twelvar ... 92CS-12055. Note 1: Maximum outside diameter of 0.440" is permitted along 0.190" ...Missing: typical | Show results with:typical<|control11|><|separator|>
  29. [29]
    [PDF] RCA_Nuvistor_data.pdf
    These nuvistor triodes feature excellent signal power gain and a noise factor significantly better than tubes currently in use in such applications. •. The high ...
  30. [30]
    Nuvistor Tubes in Radios-History+Applications for Nuvistors
    Jan 11, 2008 · The first Nuvistor type was published in “Electronic Design” in 15th April 1959 as 6CW4. Like most of the Nuvistors, the 6CW4 is a triode. ...
  31. [31]
    [PDF] Radio-Electronics - TELEVISION SERVICING HIGH FIDELITY
    builder to construct a completely professional tuner without reliance upon external equipment. The Citation Ill's front end employs the revo- lutionary Nuvistor ...
  32. [32]
    HHScott Vacuum Tubes -- 6CW4 - 6DS4 - Nuvistor Applications
    Sep 12, 2004 · * Nuvistors, being in the tube family, are high-impedance devices -- circuit components are generally less expensive. · * Lower noise figures and ...
  33. [33]
    Tube to Transistor: A Look Back at 1960s-Era Tech - Elektor Magazine
    Jan 3, 2022 · The transition from large tube equipment to small transistor gear mainly occurred in the 1960s, with the replacement of vacuum-tube technology ...Missing: entertainment | Show results with:entertainment
  34. [34]
    Radio Telemetry for the Measurement of Intracranial Pressure in
    The coil of the detecting unit was the inductor of a Nuvistor sweeping grid dip circuit. The output was differentiated and the zero crossing of the ...<|separator|>
  35. [35]
    Using the Nuvistor on V.H.F. Bands, August 1962 Electronics World
    May 20, 2021 · ... to bridge the technology gap between the sunsetting of vacuum tubes and solid state transistors. Its relatively low noise figure, small size ...
  36. [36]
    Is the Nuvistor Better Than The 12B4 For A Line Stage - diyAudio
    Aug 17, 2006 · The reason Nuvistors are so microphonic is the elements are cantilevered from the ceramic base, i.e. there is no support at the top of the ...Nuvistor phono preamp7586 nuvistorMore results from www.diyaudio.comMissing: limitations | Show results with:limitations
  37. [37]
    Can we discuss the Nuvistor please? - R/E/P Community
    Mar 27, 2006 · The Nuvistor's impedance mismatch in particular renders the formerly full low end of the U47 mic anemic, constricted and nasal. A slightly off- ...Microphonic Stanford Omega MicAKG C61 findings?More results from repforums.prosoundweb.com
  38. [38]
    [PDF] Evolution and recent advances in RF/microwave transistors
    In 1970, the state of the art Si BJTs showed minimum noise figures of 1.3, 2.6 and 4 dB at frequen- cies of 1, 2, and 4 GHz, respectively, and output powers of ...Missing: nuvistor | Show results with:nuvistor
  39. [39]
    Does anyone still make Nuvistors?
    Apr 15, 2018 · Re: Does anyone still make Nuvistors? I'm not aware of any current Nuvistor production. However, there seems to be no shortage of NOS items (RCA) ...
  40. [40]
    TekScopes@groups.io | Are Nuvistors less reliable?
    In both 422 and 454 scopes, they have grown weak and prevented the beam from being on the screen. In the 422, the Nuvistor is a low plate voltage version and ...