Antenna for 160 meters. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / HF antennas
Comments on the article
On fig. Figure 1 shows the antenna I use on 160m. It consists of a tilted radiator A and three counterweights a, b, c, stretched parallel to the ground.
Fig. 1
The antenna is fed with an unbalanced coaxial cable with a characteristic impedance of 75 ohms. The central conductor is connected to a variable capacitor C1 (Fig. 2) of a matching device, which is placed in a moisture-proof box.
Fig. 2
An SWR meter is required to tune the antenna. First, all counterweights must be disabled. Then, a feeder with a characteristic impedance of 75 ohms is connected to two of them, for example a and c, and, having connected to the transmitter, the SWR is determined in the middle and at the edges of the range. If the SWR is high, then it is necessary to adjust the counterweights by changing their geometric dimensions. A similar operation is performed with the third counterweight, having previously turned off any of the previous ones. After adjusting all counterweights, they are connected to the cable sheath and the inclined emitter is adjusted. By changing the capacitance of a variable capacitor, a minimum SWR value is achieved in the middle of the range.
In the author's version, the SWR of the antenna in the middle of the range was equal to 1.3, at the edges of the range - no more than 1.6.
Author: V. Starostin (UA3PFC), Tula; Publication: cxem.net
See other articles Section HF antennas.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
Machine for thinning flowers in gardens
02.05.2024
In modern agriculture, technological progress is developing aimed at increasing the efficiency of plant care processes. The innovative Florix flower thinning machine was presented in Italy, designed to optimize the harvesting stage. This tool is equipped with mobile arms, allowing it to be easily adapted to the needs of the garden. The operator can adjust the speed of the thin wires by controlling them from the tractor cab using a joystick. This approach significantly increases the efficiency of the flower thinning process, providing the possibility of individual adjustment to the specific conditions of the garden, as well as the variety and type of fruit grown in it. After testing the Florix machine for two years on various types of fruit, the results were very encouraging. Farmers such as Filiberto Montanari, who has used a Florix machine for several years, have reported a significant reduction in the time and labor required to thin flowers.
... >>
Advanced Infrared Microscope
02.05.2024
Microscopes play an important role in scientific research, allowing scientists to delve into structures and processes invisible to the eye. However, various microscopy methods have their limitations, and among them was the limitation of resolution when using the infrared range. But the latest achievements of Japanese researchers from the University of Tokyo open up new prospects for studying the microworld. Scientists from the University of Tokyo have unveiled a new microscope that will revolutionize the capabilities of infrared microscopy. This advanced instrument allows you to see the internal structures of living bacteria with amazing clarity on the nanometer scale. Typically, mid-infrared microscopes are limited by low resolution, but the latest development from Japanese researchers overcomes these limitations. According to scientists, the developed microscope allows creating images with a resolution of up to 120 nanometers, which is 30 times higher than the resolution of traditional microscopes. ... >>
Air trap for insects
01.05.2024
Agriculture is one of the key sectors of the economy, and pest control is an integral part of this process. A team of scientists from the Indian Council of Agricultural Research-Central Potato Research Institute (ICAR-CPRI), Shimla, has come up with an innovative solution to this problem - a wind-powered insect air trap. This device addresses the shortcomings of traditional pest control methods by providing real-time insect population data. The trap is powered entirely by wind energy, making it an environmentally friendly solution that requires no power. Its unique design allows monitoring of both harmful and beneficial insects, providing a complete overview of the population in any agricultural area. “By assessing target pests at the right time, we can take necessary measures to control both pests and diseases,” says Kapil ... >>
| Random news from the Archive TideGen Helical Subsea Turbine for Tidal Energy
08.08.2012
The original TideGen helical subsea turbine will be installed in the Strait of Fundy in the northeastern Gulf of Maine, which borders Canada and the United States. This bay is known for its record high tides, so the turbine will run at high speeds and be subjected to heavy loads.
The TideGen project is different from most underwater turbines, which have wide "fans" similar to their land-based counterparts. In contrast, TideGen is a tubular cylindrical design with spiral bladed blades. This design is highly efficient, reliable and resistant to storms. The turbine is located horizontally at the bottom. It is easy to install and does not interfere with navigation.
The first turbine will generate 150 kW at a water flow rate of 11 km/h. Later, it is planned to install another 19 turbines, which will bring the capacity of the underwater power plant to 3 MW. That's enough to power 1200 homes and small businesses in Maine.
This project can have a significant impact on tidal energy. If the settlement price for electricity (21,5 cents per kWh) can be achieved, the $21 million project will be profitable and will be a good incentive for the development of this type of generating capacity.
In the US alone, converting the movement of waves and tides into electrical energy can supply thousands of terawatt-hours per year, or about a third of all electricity currently used in the US. At the same time, compared to solar panels and windmills, underwater turbines generate a given power continuously, without large jumps.
|
Other interesting news:
▪ Landing on the nucleus of a comet
▪ Mobile networks 5G
▪ Asus ZenPad 3 8.0 tablet with 2K display
▪ The Botanical Institute of the Russian Academy of Sciences is entangled in the Internet
▪ STM32CubeIDE - new universal development tool from ST
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Funny puzzles. Article selection
▪ article Lead by the nose. Popular expression
▪ article What is the difference between new stars and supernovae? Detailed answer
▪ article Functional composition of Saba / Salora TVs. Directory
▪ article Converting old AT computer power supplies to ATX. Encyclopedia of radio electronics and electrical engineering
▪ article Spiral UHF antenna. 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