Antenna amplifier UHF. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Antenna amplifiers
Comments on the article
The simple design of a two-stage broadband antenna amplifier is designed to amplify signals in the UHF television range.
At the input of the amplifier, a tunable bandpass filter L1C2C3 is included with a bandwidth of about 50 MHz within the range from the 21st to the 60th channel of the television range. Transistors VTI and VT2 are connected according to a common emitter circuit. The first stage operates at a transistor collector current of 7 mA and to a greater extent determines amplifier parameters such as noise level and cross modulation. The second stage determines the overall gain, which is 25 dB. The collector current of the transistor VT2 is selected within 25 mA.
The input and output of the amplifier are unbalanced and are designed to connect a coaxial cable with a characteristic impedance of 75 ohms.
Power is provided by +12 V and is supplied through a feeder. The inductor L4 has an inductance of 10 μH and is wound on a ferrite ring magnetic core. Coil L1 is made of silver-plated wire with a diameter of 2 mm, has half a turn and is molded on a mandrel with an outer diameter of 4 mm. Inductors L2 and L3 have 3 turns wound with PEL-1 0,2 wire on ferrite ring magnetic cores.
The elements of the amplifier are mounted on a fiberglass printed circuit board, which is enclosed in a metal screen.
Note
Inductors L2 and L3 should be wound on magnetic cores made of ferrite grades 10VNP, 20VNP, L4 - on a magnetic core made of ferrite with a magnetic permeability of at least 1000. BFR 90 transistors can be replaced by any powerful transistors designed to operate in the microwave range (KT606, KT610, KT640, KT913 and others).
Publication: cxem.net
See other articles Section Antenna amplifiers.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
Energy from space for Starship
08.05.2024
Producing solar energy in space is becoming more feasible with the advent of new technologies and the development of space programs. The head of the startup Virtus Solis shared his vision of using SpaceX's Starship to create orbital power plants capable of powering the Earth. Startup Virtus Solis has unveiled an ambitious project to create orbital power plants using SpaceX's Starship. This idea could significantly change the field of solar energy production, making it more accessible and cheaper. The core of the startup's plan is to reduce the cost of launching satellites into space using Starship. This technological breakthrough is expected to make solar energy production in space more competitive with traditional energy sources. Virtual Solis plans to build large photovoltaic panels in orbit, using Starship to deliver the necessary equipment. However, one of the key challenges ... >>
New method for creating powerful batteries
08.05.2024
With the development of technology and the expanding use of electronics, the issue of creating efficient and safe energy sources is becoming increasingly urgent. Researchers at the University of Queensland have unveiled a new approach to creating high-power zinc-based batteries that could change the landscape of the energy industry. One of the main problems with traditional water-based rechargeable batteries was their low voltage, which limited their use in modern devices. But thanks to a new method developed by scientists, this drawback has been successfully overcome. As part of their research, scientists turned to a special organic compound - catechol. It turned out to be an important component that can improve battery stability and increase its efficiency. This approach has led to a significant increase in the voltage of zinc-ion batteries, making them more competitive. According to scientists, such batteries have several advantages. They have b ... >>
Alcohol content of warm beer
07.05.2024
Beer, as one of the most common alcoholic drinks, has its own unique taste, which can change depending on the temperature of consumption. A new study by an international team of scientists has found that beer temperature has a significant impact on the perception of alcoholic taste. The study, led by materials scientist Lei Jiang, found that at different temperatures, ethanol and water molecules form different types of clusters, which affects the perception of alcoholic taste. At low temperatures, more pyramid-like clusters form, which reduces the pungency of the "ethanol" taste and makes the drink taste less alcoholic. On the contrary, as the temperature increases, the clusters become more chain-like, resulting in a more pronounced alcoholic taste. This explains why the taste of some alcoholic drinks, such as baijiu, can change depending on temperature. The data obtained opens up new prospects for beverage manufacturers, ... >>
| Random news from the Archive Asus X79-Deluxe motherboard
12.09.2013
Asus has released the X79-Deluxe motherboard, designed for LGA2011 processors, including the recently introduced Intel Core i7 Extreme (Ivy Bridge-E) processors.
The design of the board size ATX used black and gold colors. The power subsystem is built according to a 10-phase scheme. Power is supplied via a 24-pin ATX connector and an 8-pin EPS connector. The board has eight DDR3 DIMM slots, four PCI-Express 3.0 x16 slots, and two PCI-Express 2.0 x1 slots.
Equipped with eight SATA 6Gb/s ports and four SATA 3Gb/s ports, as well as two eSATA 6Gb/s ports. The number of USB 3.0 ports is eight, and six of them are displayed on the rear panel. An important feature of the X79 Deluxe board is the WiFi GO! wireless module, which supports 802.11ac and Bluetooth 4.0.
Wired network connectivity is provided by two Gigabit Ethernet ports. An eight-channel sound subsystem and USB 2.0/1.1 ports complete the picture. The board uses proprietary technologies Asus USB BIOS Flashback, EPU, TPU II, SSD Caching and USB 3.0 Boost.
The expected price of Asus X79 Deluxe is $350.
|
Other interesting news:
▪ NEC LaVie GZ 800g Ultrabook
▪ Bird flight record
▪ Star farthest from Earth discovered
▪ Quantum computers for data processing
▪ New way to remove hydrogen from silicon surface
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Art video. Article selection
▪ article Techniques of orientation with the help of standard equipment and instruments. Basics of safe life
▪ article Why do the number of days in months differ? Detailed answer
▪ article Burdock. Legends, cultivation, methods of application
▪ article Low-frequency amplifier on the KIA6205 chip. Encyclopedia of radio electronics and electrical engineering
▪ article Microcircuits. Digital signal processor SAA7706H for car audio. Encyclopedia of radio electronics and electrical engineering
Leave your comment on this article:
Comments on the article:
Andrei
At one time I collected 5 such amplifiers, all have been working for 10 years already. This scheme was in the Radio magazine. Tuning without problems, the gain is even more than 25 dB. The board was filled with paraffin (then there were no soft sealants). In St. Petersburg, I had to put an attenuator, too much gain, but Suomi takes it. In the Smolensk region, where there are always 2 programs, they began to take 6+ (1-2-Peter-Belarus-Poland-Lithuania).
All languages of this page
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua
2000-2024
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese