VE7BQH Interactive Antennas comparison Tables

UY0LL
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З нами з: 17 січня 2009, 11:31
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VE7BQH Interactive Antennas comparison Tables

Повідомлення UY0LL » 11 липня 2017, 12:39

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.

Below are the last edition of the text files that Lionel has been producing

Antenna performance table by VE7BQH, edition August 22, 2012.

Here you will find information on how antennas behave when stacked. The antennas found in the table are the ones currenly used by people on EME. For an antenna to qualify for a place in the table it must have been built by someone, antennas that only live as computer files are not accepted.


Lionel, VE7BQH

VE7BQH Interactive Charts.xls
(645.5 Кіб) Завантажено 27 разів

UY0LL
Повідомлень: 927
З нами з: 17 січня 2009, 11:31
Reputation: 1
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Re: VE7BQH Interactive Antennas comparison Tables

Повідомлення UY0LL » 31 серпня 2017, 14:04

Пример использования файла interactive-table-Decline_Efficiency.xls (см. аттач)
Decline_Eff.png
Вкладення
interactive-table-Decline_Efficiency.xls
(82.5 Кіб) Завантажено 15 разів


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