Nuvistor
The Nuvistor is a miniaturized special design of an electron tube .
construction
It has a metal instead of a glass housing and a ceramic base , making it less susceptible to breakage. The significant reduction in the external dimensions enables direct assembly on circuit boards . The reduced internal distances between the electrodes result in changed electrical data such as increased steepness and, compared to other electron tubes, very good RF properties. Since Nuvistors are made exclusively from ceramic and metal, they also work under extreme temperature conditions.
Their production method differed significantly from that of other electron tubes: Since the design did not provide for the possibility of evacuating the piston, the entire system assembly, including the closure of the piston, was carried out under high vacuum .
commitment
The first Nuvistoren of RCA (6CW4) came in 1959 on the market - because of their extremely good electrical values at VHF - and UHF - frequencies they were in the United States mainly used in TV tuners, but also in oscilloscopes and some special applications (for example, the first amplifier stage a camera tube , various HF - amplifiers and instruments ) they made their advantageous properties advantage.
Special awareness reached the Nuvistortriode 13CW4 in connection with the two famous Neumann -U-47 and U-48 condenser microphone for professional studio applications: for reasons of profitability was the production of the preamp VF14m - a steel tubes - Pentode the company Telefunken - the late 1950s set. As a solution to the problem, the Neumann company temporarily decided on the above-mentioned Nuvistor, which replaced the VF14m after a few modifications in the circuit concept, which led to considerable sound changes. With the Nuvistor preamplifier variant, the Neumann company was no longer able to build on the great market success of the U-47 microphone with the original VF14m preamplifier.
However, the nuvistors were no longer of great and long-lasting importance - this was also due to the simultaneous development of semiconductor components , which completely replaced this type of tube.
Examples
Examples of Nuvistor Electron Tubes from RCA are:
- 7586 - first triode available on the market
- 8056 Triode for low supply voltage
- 8058 Triode for UHF applications
- 7895 - 7586 with greater steepness
- 6CW4 - Triode with high slope, mainly used in consumer electronics
- 6DS4 - successor to 6CW4
- 6DV4 - Triode with medium slope, used as a UHF oscillator, housing sometimes gold-plated
