HT refers to "High Tension" in the context of vacuum tubes, primarily used in electronics and radio applications. It typically describes the high-voltage supply required to operate certain types of vacuum tubes, like those used in RF (radio frequency) amplifiers or oscillators. In practical usage, HT voltage can range from several hundred to over a thousand volts, depending on the specific vacuum tube and its application.

A hot cathode is a type of electron source used in various vacuum devices, such as vacuum tubes and certain types of electron microscopes. In a hot cathode, the cathode is heated to a high temperature, typically using a filament, which causes it to emit electrons through a process called thermionic emission.

Acorn Tube is a popular online platform for watching and sharing videos, particularly in the realm of educational and informative content. Its content often includes short animated videos that simplify complex topics, making them accessible and engaging for a wide audience. The platform typically caters to various themes such as science, history, technology, and personal development, among others.

A Field Emitter Array (FEA) is a type of electron emitter technology that utilizes a densely packed array of nanoscale field emitters to produce electrons for various applications, primarily in vacuum devices and electronic components. The key principle behind FEAs is the phenomenon of field emission, whereby electrons are emitted from a sharp tip (or an array of tips) when subjected to a strong electric field.

A video camera tube is a type of image sensor that was used in early television and video cameras to convert optical images into electrical signals. They played a crucial role in the development of electronic imaging before the advent of solid-state sensors like charge-coupled devices (CCDs) and complementary metal-oxide-semiconductors (CMOS).

Aquadag is a colloidal graphite suspension used primarily as a conductive coating for various applications, particularly in the field of electronics and materials science. It is often employed to create a conductive layer on non-conductive surfaces or to enhance the conductivity of certain materials. Key features of Aquadag include: - **Composition**: It typically consists of finely divided graphite particles suspended in water, which gives it both conductive and protective properties.

Audion is a software application that was originally developed for macOS as an audio player and streaming client, created by the company Known as Panic. It gained popularity in the late 1990s and early 2000s for its ability to handle various audio formats and for its user-friendly interface. Audion was known for its support of internet radio streaming, allowing users to listen to live broadcasts.

A beam deflection tube, often referred to in the context of experimental physics or engineering, is a device used to measure the deflection of beams (structural members) under various loads. These tubes can be utilized in experimental setups to study the behavior of materials under stress, helping engineers understand how different types of materials and geometries will behave under load.

A beam tetrode is a type of vacuum tube that was widely used in electronics, particularly in radio transmitters and amplifiers, during the mid-20th century. It is an evolution of the tetrode, which itself is a four-electrode vacuum tube comprising a cathode, anode (plate), and two control grids. The beam tetrode introduces a design that enhances efficiency and performance.

A Direct-view bistable storage tube (DVST) is a type of display technology that was primarily used in the mid-20th century for various applications, including computer graphics and radar displays. The DVST is notable for its ability to hold an image without requiring constant refreshing, which makes it a bistable device.

The EL84 is a vacuum tube (also known as a valve) that is commonly used in audio amplification, particularly in guitar amplifiers and hi-fi audio equipment. It is a glass pentode tube that was first introduced by Philips in the late 1950s and has since become popular due to its warm sound and efficiency.

The Edison and Swan United Electric Light Company, commonly referred to as the Edison and Swan Electric Light Company, was a British company formed in the late 19th century that was primarily involved in the development and commercialization of electric lighting.

Ei Niš is a significant annual event dedicated to entrepreneurship that takes place in Niš, Serbia. It's designed to promote innovation, networking, and business opportunities among startups, entrepreneurs, and various stakeholders in the business ecosystem. The event typically features workshops, lectures, and panels led by industry leaders, entrepreneurs, and investors, aiming to share knowledge, foster collaboration, and encourage the growth of entrepreneurship in the region.

Eimac, short for "Electronic Instrument Manufacturing Company," is a well-known manufacturer of high-power vacuum tube devices, including radio frequency power amplifiers and other electronic components. Founded in the 1930s and originally based in the United States, Eimac gained prominence for its innovative designs and high-quality products primarily used in broadcasting, communications, industrial heating, and medical applications.

Electron-stimulated luminescence (ESL) is a phenomenon where specific materials emit light when they are bombarded with electrons. This effect occurs as a result of the interaction between the incoming electrons and the electrons in the material. When the high-energy electrons collide with the atoms in the material, they can excite electronic states, leading to the emission of photons as the excited electrons return to their ground state.

An evacuation tip generally refers to advice or guidance meant to help individuals safely and effectively evacuate a building, area, or location in the event of an emergency. Here are some common evacuation tips: 1. **Know the Exits**: Familiarize yourself with all the exits of your building or area in advance, including alternative routes if primary exits are blocked.

A Field Emission Gun (FEG) is a specialized type of electron source used in electron microscopy and other applications that require high-resolution imaging or precise electron beams. It operates on the principle of field emission, which is the emission of electrons from a sharp tip (the emitter) when subjected to a strong electric field. ### Key Features of Field Emission Guns: 1. **Emitter Structure**: The emitter typically consists of a sharp metal tip made from materials like tungsten or carbon.

JJ Electronic is a well-known manufacturer of vacuum tubes and related electronic components, particularly within the audio and musical instrument industries. Based in Slovakia, JJ Electronic produces a variety of high-quality tubes used in amplifiers for electric guitars, hi-fi audio equipment, and other applications. Their products include several types of vacuum tubes, such as preamp tubes (12AX7, 12AT7, etc.) and power tubes (EL34, 6L6, etc.