Delta from 10 to 40 meters. Scheme, description

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Delta from 10 to 40 meters. Encyclopedia of radio electronics and electrical engineering

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Encyclopedia of radio electronics and electrical engineering / HF antennas

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During an on-air conversation with Mike (G4HOL), I learned about his compromise antenna. His "story" was written almost word for word. But, first of all, for a better understanding, I will give a picture illustrating what has been said. Comment G4HOL: The perimeter of the antenna, as seen in the figure is 43,13 meters. The location above the ground is horizontal. On the 40 m band, it works at a large angle to the horizon. As the frequency increases, the radiation angle decreases and the gain increases. The antenna is non-resonant.

Delta from 10 to 40 meters

It starts working after correct adjustment of the antenna tuner's control elements. With it, it is possible to obtain an SWR value of 1 on almost all ranges. With an input power of 300 - 400 W, TVIs are not detected. Recommended as an antenna for use in field conditions. Comment by EW1MM: From a theoretical point of view, there are no contraindications to the use of this antenna. However, based on the formula for determining the perimeter of such antennas L = 306,3 / F (MHz), its perimeter should be slightly increased to 43,44 m (for a frequency of 7.050 MHz). On other bands everything will be sorted out using a symmetrical tuner.

It is very important to use, namely, a symmetrical tuner without the use of transformers, for example, the USS unit from the R-140 r / st or see the book by Benkovsky and Lepinsky "HF / VHF waves antennas", p. 152. In stationary conditions, in terms of losses, it is better to use a home-made two-wire feeder 450 ... 600 Ohm. For operation in the range of 10 - 80 m, the antenna perimeter should be calculated based on the range of 80 meters. The antenna can be positioned vertically if necessary. If it is not possible to obtain an SWR close to one due to the imperfection of the antenna tuner, then the length of the symmetrical feeder should be slightly changed.

Comment RW3AY: There is a lot of interest in such antennas, and it seems to me that we should turn to professionals for clarification. I think Vladimir (EW8AU) will not refuse to comment on what has been said, and I, in turn, will be able to inform our readers in the future.

Author: I. Podgorny. EW1MM, Minsk; Publication: N. Bolshakov, rf.atnn.ru

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