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Free technical library for hobbyists and professionals

As of December 08, 2023 in the database 500000 articles

Random section of the Free Technical Library:

Measurements, tuning, antenna matching

Read interesting articles:

Influence of SWR on the operation of the radio station, HF bridge - panoramic SWR meter, HF bridge of the VHF band, Remote antenna indicator, GIR for tuning wire antennas, Meter of impedances of broadcasting antennas of LW and MW ranges, Antenna current meter, Measure antenna parameters? It's not difficult at all!, Satellite dish pointing indicator, How to shorten a dipole, Circuits for a HF antenna, SWR meter for VHF band, Methods of supply and execution of magnetic loop antennas, Tuning antennas and circuits with a jammer, Tuning antennas with a frequency response meter ... all articles of the section >>


Regularly replenished compilation the most interesting news of science and technology, new electronics. Large archive of articles from 2000 to 2023. Based on materials from periodicals and the Internet.

Latest news of science and technology, new electronics:

Cats watch their owners without even seeing them 06.12.2023

Scientists in Japan have conducted a surprising experiment revealing that cats have a unique ability to track the location of their owners, even when they are out of sight. During the scientific work, 23 cats and 27 felines were subjected to careful analysis, revealing the unexpected cognitive abilities of these mysterious animals. The experiment expands our understanding of cats' cognitive abilities and highlights the depth of the bond between these enigmatic pets and their owners. Tracking the location of owners without visual contact highlights surprising aspects of feline intelligence and creates new horizons for future research in behavioral biology. 27 cats who lived in the cat cafe and the scientists’ pets took part in an experiment in which recordings of the owners’ voices were used. Surprisingly, the cats showed a special reaction, even from different corners of the room, when they heard their name. These results support the hypothesis ... >>

Global warming is causing coral bleaching 06.12.2023

Changing ocean temperatures caused by global warming are becoming a key cause of coral bleaching around the world, warns the US National Oceanic and Atmospheric Administration (NOAA). This process, in which corals lose their colorful algae and turn white, has been seen from the Great Barrier Reef in Australia to the waters of Florida. Scientists warn that corals need extended periods of cool water to successfully recover from bleaching. In light of this problem, research is being conducted and measures are being taken to maintain the health of reefs, such as limiting anchorage and controlling invasive species. All this underscores the urgency of taking action to curb climate change and preserve the unique ecosystems of the oceans. Derek Manzello, director of Coral Reef Watch, emphasizes that coral bleaching has already been recorded in 35 countries and territories around five oceans and seas. Experts fear that the EU ... >>

Hair coloring using champignon enzyme 05.12.2023

A new perspective on hair coloring is provided by mushrooms and their enzymes, according to research by American scientists. The new approach promises to be safe, effective and pleasant for hair, without causing allergies, which often occur with traditional dyes. Cosmetology research offers a promising look at the future of hair coloring based on the use of an enzyme from mushrooms. This innovative technique, providing safe and effective coloring, could be a revolutionary step in the beauty industry. The beauty industry, traditionally focused on chemicals, is now turning its attention to nature. In the process of researching mushrooms, in particular champignons, scientists discovered enzymes responsible for the synthesis of the natural pigment melanin. This pigment plays a key role in determining the color of human hair and skin, and also protects against ultraviolet radiation. The technique is based on creating a connection between melanin molecules and amino acids ... >>

Random news from the Archive

Bees and math 30.09.2018

A tiny brain is not a sign of a lack of intelligence. This conclusion was reached by scientists from France and Australia, who studied the mathematical abilities of bees, namely their ability to understand the position of zero in a series of numbers.

For the study, white plates with dots were used. Food was laid out on them in a certain order. Real food was placed on plates with the fewest black dots. The rest were covered with quinine solution. During the experiment, the bees quickly realized that the largest amount of real treats, and not quinine, is on a plate with a zero indicator, that is, where there were no points at all. From this, scientists concluded that bees are able to count up to five, and also understand what zero is.

According to the researchers, "Zero" is a rather complicated mathematical concept. For a very long time it was believed that only a person is capable of realizing it, because he has abstract thinking. However, earlier experiments had shown that birds and monkeys could also detect zero.

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Encyclopedia of radio electronics and electrical engineering. Articles with diagrams, illustrations, comments

In section Encyclopedia of radio electronics and electrical engineering presents the most interesting electronic designs, diagrams, descriptions, reference materials with illustrations and explanations.

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Encyclopedia of radio electronics. The best articles for radio electronics


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Effective means for relaxation and good mood

A random story from the life of a radio amateur:

I lived in Abkhazia for four years in the town of Gudauta. Beautiful place. TV repair was like a hobby. One morning there was a knock at our door very early. It was an elderly woman who, having bowed, called me to her to repair the TV. I couldn't refuse her. At that time, a strong thunderstorm passed, and thunderstorms in Abkhazia are very strong. The antenna was on a very high mast, well then there were no antenna amplifiers, otherwise we would have to climb up. The repair was hard. The TV was struck by a thunderstorm in many places. But what was most striking was that this woman put a chair next to the TV and did not go anywhere. I tried to talk to her, but she did not enter into conversations, she just watched me work. Psychologically, it weighed heavily on me. There was no circuit, there were many defects, and on the second day of such hypnosis, my hand broke and I closed the microcircuit leads with a probe from the oscilloscope, of course it was knocked out. I went home in a bad mood and found this chip with difficulty (in those days it was a rarity). For the first time I could not sleep for a long time, I was nervous, I had nightmares. Finally, on the third day, I finished him off, earned their TV. But the woman did not leave my side all these three days. I also made a refrigerator for them that evening, and the antenna had to be lowered and put in place. They paid me royally, I left with two canisters of fine wine made for myself, so viscous, thick and tasty from the Isabella variety, which I have never met anywhere else. All my life I remember that wine, but all my life I remember that woman who sat next to me for three days.
Other stories from the life of radio amateurs | Random fun story

Random fun puzzle:

Three calves, how many legs?

Other fun puzzles | Random fun puzzle

Random Question Quiz Online:

What molecule was deciphered in the Human Genome Project?

Other Quiz Questions | Random five questions

Random aphorism:

“He is stupid who does not recognize fools, and even more stupid is he who, having recognized them, does not leave them. Dangerous in superficial communication, they are destructive in trusting proximity” (Baltasar Gracian)
Other aphorisms | Random aphorism

Random proverb:

The clear sky is not afraid of lightning. Greek proverb
Other proverbs of the peoples of the world | Random proverb

Random phraseological unit:

All this would be funny if it weren't so sad
(About an outwardly tragicomic, funny, but essentially very serious, disturbing situation)
A quote from M. Yu. Lermontov's poem "A. O. Smirnova" (1840): "I want to tell you a lot without you, // With you, I want to listen to you ... // What should I do? .. With unskillful speech // I'm not allowed to occupy your mind... // All this would be funny, // If it weren't so sad.
Other phraseological units | Random phraseological unit

Random fact "Did you know?":

With age, the sense of smell is weakened. According to a survey of 2500 older Americans, weakening is noticeable in a quarter of people over 53 and 60 percent over 80. But only 10-18 percent of those affected notice this age-related disorder. It is more pronounced in men, especially smokers.
Other Facts "Did You Know?" | Random interesting fact

Random article of the Great Encyclopedia for Children and Adults:

In what era was beer the most popular drink in Europe?

In medieval Europe, especially in the northern and eastern parts of it, beer was a truly massive drink - it was consumed by people of all classes and ages. For example, in England, beer consumption per capita reached 300 liters per year, although now this figure is about 100 liters, and even in the Czech Republic, which is the leader in this parameter, it is slightly more than 150 liters. The main reason for this was the poor quality of the water, which was eliminated during the fermentation process.

Other articles of the Great Encyclopedia | Random article of the Great Encyclopedia

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