Radio station on three transistors. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Civil radio communications
Comments on the article
The radio station is designed for two-way communication in the range of 27 MHz with amplitude modulation. It is assembled according to the transceiver scheme. The cascade on the transistor VT1 serves as both a receiver and a transmitter. The amplifier on transistors VT1 and VT2 in the receive mode amplifies the signal allocated by the receiver, and in the transmit mode it modulates the carrier.
(click to enlarge)
During installation, special attention should be paid to the location of the capacitors C10 and C11. They are used to prevent self-excitation. If self-excitation still occurs, then it is necessary to connect additionally several more capacitors of the same capacity.
About setting. She is very simple. First, using a frequency meter, the transmitter frequency is set, and then the receiver of another radio station is tuned for maximum noise suppression and the highest signal volume.
The L1 coil tunes the transmitter, and the L2 coil tunes the receiver. Tp1 - any small-sized output transformer. Ba1 - any speaker of suitable size with a winding resistance of 8 - 10 ohms. Dr1 - DPM-0,6 or home-made: 75 - 80 turns of PEV 0,1 on a MLT resistor 0,5 W - 500 kOhm. The rest of the details are of any type. The coils are wound on frames with a diameter of 8 mm and contain 10 turns of PEV 0,5 wire.
Printed and circuit board - in fig. 2
Technical data
Supply voltage - 9 - 12 volts Communication range in open areas - about 1 km. Current consumption: receiver -15 mA transmitter - 30 mA. Telescopic antenna - 0,7 - 1m. Case dimensions - 140 x 75 x 30 mm.
Author: N. Marushkevich, Minsk; Publication: N. Bolshakov, rf.atnn.ru
See other articles Section Civil radio communications.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
A New Way to Control and Manipulate Optical Signals
05.05.2024
The modern world of science and technology is developing rapidly, and every day new methods and technologies appear that open up new prospects for us in various fields. One such innovation is the development by German scientists of a new way to control optical signals, which could lead to significant progress in the field of photonics. Recent research has allowed German scientists to create a tunable waveplate inside a fused silica waveguide. This method, based on the use of a liquid crystal layer, allows one to effectively change the polarization of light passing through a waveguide. This technological breakthrough opens up new prospects for the development of compact and efficient photonic devices capable of processing large volumes of data. The electro-optical control of polarization provided by the new method could provide the basis for a new class of integrated photonic devices. This opens up great opportunities for ... >>
Primium Seneca keyboard
05.05.2024
Keyboards are an integral part of our daily computer work. However, one of the main problems that users face is noise, especially in the case of premium models. But with the new Seneca keyboard from Norbauer & Co, that may change. Seneca is not just a keyboard, it is the result of five years of development work to create the ideal device. Every aspect of this keyboard, from acoustic properties to mechanical characteristics, has been carefully considered and balanced. One of the key features of Seneca is its silent stabilizers, which solve the noise problem common to many keyboards. In addition, the keyboard supports various key widths, making it convenient for any user. Although Seneca is not yet available for purchase, it is scheduled for release in late summer. Norbauer & Co's Seneca represents new standards in keyboard design. Her ... >>
The world's tallest astronomical observatory opened
04.05.2024
Exploring space and its mysteries is a task that attracts the attention of astronomers from all over the world. In the fresh air of the high mountains, far from city light pollution, the stars and planets reveal their secrets with greater clarity. A new page is opening in the history of astronomy with the opening of the world's highest astronomical observatory - the Atacama Observatory of the University of Tokyo. The Atacama Observatory, located at an altitude of 5640 meters above sea level, opens up new opportunities for astronomers in the study of space. This site has become the highest location for a ground-based telescope, providing researchers with a unique tool for studying infrared waves in the Universe. Although the high altitude location provides clearer skies and less interference from the atmosphere, building an observatory on a high mountain poses enormous difficulties and challenges. However, despite the difficulties, the new observatory opens up broad research prospects for astronomers. ... >>
| Random news from the Archive The perfect snack for heart health
09.06.2020
According to doctors from the UK, almonds can be considered an ideal daily snack that benefits the heart - it effectively protects against the development of many pathologies of the cardiovascular system.
King's College London has determined that regular consumption of almonds improves the functioning of blood vessels (not to mention other health benefits). For this reason, they consider the product to be the perfect snack.
The use of almonds helps to reduce the level of fat in the abdominal cavity and "bad" cholesterol in the vessels, which are the leading markers of heart disease. They conducted a study involving almost 7 thousand people (specialists monitored the nutritional habits of the subjects). It turned out that it was almond lovers who had the best indicators of heart health.
People who prefer to snack on nuts during the day tend to consume less carbohydrate foods, trans fats, and salt in general.
Another experiment showed that by replacing 20% of junk food consumed daily with almonds, people can reduce their personal risk of heart disease by 32%. The antioxidants of this nut protect blood vessels from the harmful effects of free radicals, which can disrupt blood flow to the myocardium and provoke the development of coronary heart disease.
|
Other interesting news:
▪ Battery as part of the body
▪ plant cement
▪ Medical mask that you can eat in
▪ fungus against drugs
▪ Cart in the phone
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Car. Article selection
▪ article It's too early for us to die - we still have things to do at home. Popular expression
▪ article Why conduct a population census? Detailed answer
▪ Rhododendron article. Legends, cultivation, methods of application
▪ article Touch input switch. Encyclopedia of radio electronics and electrical engineering
▪ article A simple HF converter for a car receiver. Encyclopedia of radio electronics and electrical engineering
Leave your comment on this article:
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