en:qha
Differences
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en:qha [2019/03/18 21:48] – created fluktuacia | en:qha [2019/03/20 16:59] (current) – fluktuacia | ||
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===== Construction ===== | ===== Construction ===== | ||
- | Structural parts of the antenna are primarily made of galvanised steel components. Those parts, which are under a higher current load are made of copper | + | Structural parts of the antenna are primarily made of galvanised steel components. Those parts, which are under a higher current load are made of copper |
Antenna’s dimensions were optimised using a [[https:// | Antenna’s dimensions were optimised using a [[https:// | ||
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* Helix height : 312.2 mm (angle of inclination 27 degrees) | * Helix height : 312.2 mm (angle of inclination 27 degrees) | ||
* Cutting length of upper cross (??Řezná) : 369.9 mm | * Cutting length of upper cross (??Řezná) : 369.9 mm | ||
- | * Cutting | + | * Cutting |
==== Material ==== | ==== Material ==== | ||
- | Fázovací | + | Phasing lines (?? fázovací |
+ | Antenna helix is made of copper tubes with outer diameter of 18 mm. The tubes are made of ‘soft’ copper, used in air-conditioning units installations. They are available in reel that makes it much easier to construct the antenna. | ||
- | Šroubovice antény je tvořena měděnými trubkami o vnějším průměru 18mm. Jde o " | + | {{: |
- | {{: | ||
+ | * 400x Galvanized | ||
- | * 400x Pozinkovaný trhací nýt 4.8x10 mm | ||
- | * | ||
- | z==== Výroba | + | ==== Construction |
- | {{: | + | {{: |
- | Anténa se skládá ze čtyř kusů základnových čtverců sloužících, | + | The antenna is made of four pieces of base squares that serve as a universal ground potential. These squares are screwed together at each side by a four M8 screws. There is a fan washer (?? vějířová podložka) at both sides of the screw. A reason for this is a better conductivity of connection and, at the same time, better prevention against a spontaneous loosening during manipulation with antenna. |
- | {{: | + | {{: |
- | Zkratovací kříž na vrcholu helixu je sletován ze 3kusů trubek z " | ||
- | Kříž | + | Zkratovací kříž |
- | {{: | + | The cross is thus made of one longer tube with two shorter ones soldered perpendicularly to it. The shorter tubes have their walls pierced, so they fit precisely to the longer tube. It is also necessary to keep the sum of the lengths of the tubes such, that both arms of the cross measure 370 mm. |
+ | {{: | ||
- | ===== Naměřené charakteristiky ===== | ||
- | Na sestavené anténě bylo měřeno přizpůsobení antény. K měření byl použit spektrální analyzátor DSA815-TG s [[http:// | + | ===== Measured characteristics ===== |
- | {{:cs: | + | The assembled antenna underwent a measurement of adaptation (přizpůsobení antény) using a spectral analyser DSA815-TG with [[http://www.ebay.com/ |
+ | {{: | ||
- | Anténa je citlivá na způsob připojení fázovacího vedení. Dvě základní možnosti jsou vidět na následujících obrázcích, | + | The antenna is sensitive to the way of connecting the phasing lines. Two basic possibilities can be seen on the following pictures. They differ in the direction of the rotation of the antenna feeds phase (?? |
- | {{: | ||
- | {{: | ||
- | Na grafu je vidět rezonance antény na přibližně 160 MHz. Anténa tak rezonuje poněkud výše, oproti modelu. Zatím není známa přesná příčina tohoto jevu, ale je možné, že je způsobena změnou činitele zkrácení vlivem změny teploty koaxiálního kabelu na přímém slunečním světle. | + | {{: |
+ | {{: | ||
+ | As you can see on the graph, the resonance of the antenna is approximately 160 MHz, which is a bit higher compared to model. The exact cause of this phenomenon is not yet know. It might be caused by a change of velocity factor (?? činitel zkracení) due to temperature changes in coaxial cable under direct sunshine. | ||
- | {{: | ||
- | {{: | ||
- | Při opačném zapojení fázovacího vedení se na anténě, žádná výrazná rezonance, která by odčerpávala přiváděnou energii neprojevuje. | + | {{: |
+ | {{: | ||
+ | When connecting the phase lines conversely, there is no considerable resonance observable, which would drain the supplied energy. | ||
- | ====== | + | ====== |
- | * [[http:// | + | * [[http:// |
en/qha.txt · Last modified: 2019/03/20 16:59 by fluktuacia