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Пятница, 21.06.2024, 08:11
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Интерактивные таблицы VE7BQH


См. по ссылке таблицу сравнения антенн, доработанную Владимиром, UR5EAZ


Комментарии от VE7BQH:

To All: Attached is the latest VE7BQH G/T Tables. There has been a substantial change to the Tables this month.

Tsky and Tearth is now Interactive or changeable by the user. I would like to thank Vladimir, UR5EAZ for coming up with the idea and developing the actual EXCEL. Well done! The original Tsky and Tearth were developed in 1996.

Since then as we all are aware there has been a notable increase in noise on these bands due to a wide range of man made devices. As an example several measurements taken in Urban areas show that it is no longer possible to see 200K cold sky especially with up to 4 yagis arrays.

The biggest increase has been in ground noise. As an example of some Urban measurements on 144 MHz, The best Tsky seen was 290K and the Tearth was 4000K. In some cases 5000K. The impact of using 290K and 4000K in the 144 MHz Table means antennas with low noise characteristics start to stand out over an average antenna. Stations can now determine their own Tsky and Tearth characteristics, plug in the numbers and better evaluate the performance of their antenna.

Lionel, VE7BQH

Категория: Уголок конструктора | Добавил: ut5el (26.06.2017)
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