Menu English Ukrainian russian Home

Free technical library for hobbyists and professionals Free technical library


Amateur radio calculations. Schemes, articles, descriptions

Free library / Schemes of radio-electronic and electrical devices

Amateur radio calculations

We recommend reading in our Free Technical Library:

Sun tracker



Section Alternative energy sources. Until now, when operating solar panels, we have been content with the total dispersion of sunlight. True, some seasonal changes were taken into account, as well as the time of day (orientation in the east-west direction). Nevertheless, the solar panels remained more or less fixed in the working position once found. In a number of cases, we did not even attach much importance to this, approximately exposing the battery in the direction of the sun. However, it is known from experience that solar cells generate maximum energy only when they are exactly perpendicular to the direction of the sun's rays, and this can happen only once a day. The rest of the time, the efficiency of solar cells is less than 10%. ... >>

Microwave laboratory synthesizer



Section Measuring technology. The problem of frequency stability in transceivers has always existed. At relatively low frequencies (up to 100-150 MHz), it was solved using quartz resonators, at higher frequencies (400 MHz) - using surface-acoustic wave resonators (SAW resonators), while high-Q dielectric resonators are often used to stabilize ultrahigh frequencies. ceramics or other high-quality resonators [1]. The described methods of stabilization with the help of passive components have their advantages - simplicity and relatively low cost of implementation, but their main drawback is the impossibility of any significant frequency tuning without changing the frequency-setting element - the resonator. The impossibility of fast electronic tuning of the operating frequency while maintaining its stability sharply limits the use of radio devices, not allowing, for example, to implement multi-channel ... >>

Zener diode as a ballast



Section Voltage stabilizers. If the voltage on the secondary winding of the mains transformer is too high for the stabilizer used (Uvyp = 50 ... 100 V), and you don’t want to rewind the transformer, you usually use a ballast resistor of the appropriate rating and power, connected in series with the load. This solution is optimal for a fixed load current, but if it changes significantly, it is better to use a zener diode instead of a resistor, as shown in the figure. At currents up to 100 mA, it is convenient to use D816A, B, C, G, up to 500 mA - D815G, D, E, G. Zener diodes can be connected in series, the voltage they quench will be equal to the sum of the source of zener diodes: Uout \u1d Uvyr - EDst. An interesting feature of this inclusion is the ability to use a smoothing capacitor CXNUMX of smaller dimensions and cost, because voltage Uout is allocated on it, and not Urect ... >>

To any article in this section and all Encyclopedias you can leave your comment.

Articles on amateur radio calculations

Articles on amateur radio calculations; descriptions of amateur radio calculations: 40 articles

 


 

Radio amateur calculations (collection of articles)

Articles on amateur radio calculations; descriptions of amateur radio calculations: 20 articles

 


 

Latest news of science and technology, new electronics:

The speech of sperm whales is similar to that of humans 18.05.2024

In the world of the ocean, where the mysterious and unknown coexists with the studied, sperm whales, with their huge brains, are of particular interest to science. Researchers, working with a huge array of audio recordings collected during the Dominica Sperm Whale Project (DSWP) - more than 8000 recordings, seek to unravel the secrets of their communication and understand the structure and complexity of the language of these mysterious creatures. By studying in detail the recordings of 60 sperm whales in the eastern Caribbean, scientists have revealed surprising features of their communication, revealing the complexity of their language. "Our observations indicate that these whales have a highly developed combinatorial communication system, including rubato and ornaments, which indicates their ability to quickly adapt and vary during communication. Despite significant differences in evolution, sperm whales have elements in their communication that are characteristic of human communication," says Shane Gero, a biologist at Carleton University and director of the CETI project. Issl ... >>

Electron spin for quantum information transfer 18.05.2024

The transfer of quantum information remains one of the key tasks of modern science. Recent advances in the use of electron spin to expand the capabilities of information transfer in quantum systems have become very important. Researchers at Lawrence Berkeley National Laboratory are pushing the frontiers of quantum information science by experimenting with the possibilities of electron spin. Electron spin, a natural quantum bit, is a potentially powerful means for storing and transmitting information in quantum systems. Magnon wave packets, collective excitations of electron spin, have revealed their potential to transmit quantum information over significant distances. The work of Berkeley Lab researchers has revolutionized the way such excitations propagate in antiferromagnets, opening up new prospects for quantum technologies. Using pairs of laser pulses, scientists disrupted antiferromagnetic order in one place and simultaneously studied it in another, creating ... >>

Sound-absorbing silk 17.05.2024

In a world where noise is becoming increasingly intrusive, the emergence of innovative materials that can reduce its impact is of great interest. MIT researchers have unveiled a new sound-absorbing silk fabric that promises to revolutionize quiet spaces. The Massachusetts Institute of Technology (MIT) has made significant breakthroughs in the field of sound absorption. Researchers have developed a special silk fabric that can effectively absorb sound and create cozy, quiet environments. The fabric, thinner than a human hair, contains a unique vibrating fiber that is activated when voltage is applied to it. This feature allows the fabric to be used to suppress sound waves in two different ways. The first method uses fabric vibrations to generate sound waves that cover and cancel out unwanted noise, similar to noise-canceling headphones. This p ... >>

Random news from the Archive

Between any people less than 6 handshakes 26.01.2012

According to a well-known theory, every person on Earth is separated from any other by only six handshakes.

Researchers from the University of Milan decided to check whether this statement is true. They analyzed connections between 721 million Facebook users, totaling 69 billion connections, and found that the average chain length between any two users was only 4,74 people. Also, according to the results of the study, it became known that half of the participants in the social network have more than 100 friends.

Another interesting fact was that in more closed communities - for example, limited to one country or instant messaging system - this chain is longer. So, in 2008, Microsoft analyzed the connections between 180 million users of its Microsoft Messenger service. It was found that within it, the length of the chain between two people is 6,6 people.

Other interesting news:

▪ Technology developed to extract water from the moon

▪ 2D material 1 atom thick

▪ Thought controls the genes

▪ Flexible Battery

▪ Autonomous X-ray machine with artificial intelligence

News feed of science and technology, new electronics

 

Interesting materials of the Free Technical Library:

▪ section of the site Data transfer. Article selection

▪ article Horus gave birth to a mouse. Popular expression

▪ article What acts did the Viking Thorvald, his son Eirik Raudi and grandson Leif Eirikson enter into the history of geographical discoveries? Detailed answer

▪ article Making cold. Children's Science Lab

▪ article What to take with you for search work with a metal detector. Encyclopedia of radio electronics and electrical engineering

▪ article Transformerless support power supply. Encyclopedia of radio electronics and electrical engineering


All languages ​​of this page

Home page | Library | Articles | Website map | Site Reviews

www.diagram.com.ua

www.diagram.com.ua
2000-2024