Beginner radio amateur. Schemes, articles of the Free Technical Library

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Free library / Schemes of radio-electronic and electrical devices

Beginner radio amateur. Schemes, articles, descriptions

Free library / Schemes of radio-electronic and electrical devices

Beginner radio amateur

We recommend reading in our Free Technical Library:

Broadband vertical radiator

VHF Antenna Section. Georgy Alekseevich Rumyantsev (UA1DZ) developed and successfully operated an antenna consisting of eight phased broadband vertical radiators. Such radiators can be used both by themselves and as elements of complex antennas. The broadband vertical emitter UA1DZ gives a maximum radiation at a small angle to the horizon; when conducting long-range communications, it turns out to be equivalent to a three-element wave channel. Power is supplied to the emitter via a coaxial cable with a characteristic impedance of 100 ohms. SWR in the cable does not exceed 1,2 in the frequency band from 10 to 30 MHz ... >>

High security digital lock

Section Security devices and signaling of objects. No tricks will help the burglar open the 15-bit electronic lock described below. When selecting at a speed of one combination in 10 s, it will take about 1,5 million years to randomly find the correct code. The work of a potential attacker is further complicated by the fact that the circuit is automatically reset when any wrong combination is entered. In this case, it is required to resume the set order, which makes it impossible to use any ordered trial and error method. The circuit contains an EPROM with a capacity of 512x4 bits, in which, in addition to the correct one, 32 more combinations can be placed, which will allow you to periodically change the cipher by simply switching them. ... >>

Artificial grounding

Electrical section. Most often, an artificial grounding conductor is a steel conductor laid horizontally or vertically (obliquely) in the ground, or a group of such conductors interconnected. In the latter case, the ground electrode is called complex, and if the electrodes form a circuit, then such a complex earth electrode is called a ground circuit. The name horizontal and vertical ground electrodes is rather conditional. Strict adherence to horizontality in the first case is not necessary, it is important that the electrodes are in the ground at the right depth, without being damaged during the operation of the machines. Since the surface of the earth in ravines, on slopes and in a number of other places may not be horizontal, then extended (beam) ground electrodes will follow the curvature of the surface. For vertical electrodes, strict adherence to verticality is also not necessary. ... >>

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Articles for a beginner radio amateur

First acquaintance with the radio
radio reception
Encyclopedia of a beginner radio amateur

First acquaintance with the radio

Articles on the simplest radio receivers; circuits of the simplest radio receivers; descriptions of the simplest radio receivers: 5 articles

radio reception

Articles on radio reception; diagrams of devices for radio reception; descriptions of devices for radio reception: 10 articles

Based on the book by Borisov V.G. Young radio amateur

Encyclopedia of a beginner radio amateur

Articles for a beginner radio amateur; diagrams for a beginner radio amateur; descriptions for a beginner radio amateur: 429 articles

Latest news of science and technology, new electronics:

Artificial leather for touch emulation 15.04.2024

In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>

Petgugu Global cat litter 15.04.2024

Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>

The attractiveness of caring men 14.04.2024

The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>

Random news from the Archive

Ultra-compact 4G network 07.06.2016

Nokia has unveiled a lightweight and ultra-compact 4G network solution based on a small cell that allows you to deploy secure mobile communications in minutes to provide life-saving services. The solution can provide voice, video and data transmission in emergency situations, in remote areas, at various events, and can also be used as an access point by operators, companies from various industries and public security agencies.

Nokia pioneered the development of small-scale networking equipment in the industry with the introduction of the Network in a Box solution last year. Continuing work on the concept of rapidly deployable networks has resulted in the Ultra Compact Network solution, which is based on small cell technology. The Ultra Compact Network provides secure indoor and outdoor 4G coverage up to 75 km for up to 400 users.

In remote and underserved areas, this solution will help increase capacity and coverage, and operators can use it to expand their macro networks through the ability to use cable, satellite and radio relay channels for signal transport.

For first responders, the Ultra Compact Network solution will provide video, telephone, and data communications in emergency situations in the event of a disruption to cellular networks. No roads are required for delivery to the site - the equipment fits in a backpack, and when conducting search and rescue operations, when extinguishing extensive forest fires or during floods, it can be lifted into the air on a drone or weather balloon.

Deployed in remote industrial sites such as mines, refineries or oil wells, the Ultra Compact Network will provide business-critical communications; Mobile operators can use it to quickly close coverage gaps, temporarily add capacity and coverage when traffic spikes during mass events such as outdoor music festivals.

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