DG7YBN / Ant.-Soft / Antenna G/T Calculators by F5FOD   Last Update Dec 23th 2019
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Introduction
Basic Program AGTC_anyGTa_2lite  New
Basic Program AGTC_2lite
Basic Program AGTC_lite
Demonstration why to use AGTC_lite
Basic Program AGTC
MS Excel Calculators
FFTab of ideal isotropic antenna

Antenna G/T Calculating Software by F5FOD with DG7YBN

Preface

As conceived the Antenna Temperature concept is meant for terrestrial-to-space communication. It is a theoretical concept using a model environment. The Antenna under Test (AUT) is enclosed in a lower hemisphere (T-earth) and a upper (T-sky). The Y-factor = T_hot / T_cold shows that T-ant becomes useful for antenna optimisation at above approx. 70 MHz. In Antenna Simulation Software we can adjust pattern computation step size in degrees. The little patch enlighted in the sky hemisphere (in sketch on left) is one of the resulting step size patches. The example shows just a single patch in straight main beam direction. Actually both hemispheres are clad with patches all over. Each of them shines onto the AUT's pattern with a brightness temperature. Depending on the hemisphere, the patch which belongs to this is either T-earth or T-sky. The AUT's radiation pattern holds the gain coresponding to each patch, starting with a normalised 0 dB in beam direction and likewise -24 dB for a side lobe. Now the pick up of noise power per patch is summed up, averaged over the full sphere and expressed in Kelvin. This is the AUT's antenna temperature.

Same in explicite for calculating Antenna Temperature Ta, sketch: F5FOD

How many radio enthusiasts have been looking up this website since Dec. 2016?

Intro

The Antenna G/T Calculators project AGTC is built around two completely different methodological methods:
• Without mathematical rotation: AGTC_lite
• With mathematical rotation: AGTC and AGTC_fast

In each case, you can use two different tools:
• a program
• a Far Field table feeder azel plus a Microsoft Excel® work sheet.

All the program source codes are free and fully available. They are very documented so you may rewrite them in any language and interface you want.

In Dubus 4/2017, it is mathematically demonstrated that AGTC_lite produces the most accurate results.
Fortunately it is the simplest and the fastest!

References

• Antenna G/T Calculators with Open Source Code, F5FOD with DG7YBN, Dubus 1/2017, 2/2017, 3/2017 and 4/2017

AGTC_anyGTa_2lite, a DOS Console program

The AGTC_anyGTa_2lite is a DOS Console program.
The anyGTa_2lite version was developed to open the program for computing any models with any Average Gain. It also allows entering new FFTab files in a row. It is so to speak the workhorse in the AGTC family of programs:

Latest Release: AGTC AnyGTa 2lite V2.00

 • Shows T_loss_IN and T_loss_OUT:

Elder Release: AGTC AnyGTa 2lite V1.58

• 3 decimal digits instead of 2 for T_pattern, T_loss and T_total displays *.
• Copes with T_total <= 0 K now to handle even antenna models with Average Gain >> 1.
(In such a case, G/Ta value/s is/are replaced by "-99.999*" in a special color
and one single warning message in the same color is added at the bottom of the screen
when this happens on one line or any different lines whatever the number of such lines.)

3 digits for Antenna temperatures and G/Ta ... are these serious numbers?
Yes and no. In a free citation of DJ9BV 'anything below -30 dB are computed artefacts only' we can even question
giving 2 digits. But as technology moves on we encountered challenges with very long Yagis (> 7 wl) for 432 MHz
for which T_pattern and T_loss are so close while T_earth is so high that judging these even the 3rd digit margin counts.

AGTC_anyGTa_2lite is developed in Basic. The .exe file is compiled with the QB64 compiler.

AGTC_2lite, a DOS Console program

The AGTC_2lite is a DOS Console program.
The 2lite version was developed to enable computing new antennas ie. FFtab files without having to restart the program. After computation of an antenna G_T is completed. By pressing any key the next antennas FFtab file can be entered. It holds the key features as AGTC_lite with these exceptions:

• No output file being generated,
• No choice of span of computed antenna tilt angles,
• Fixed output in a 5 degrees per step tilt angle table.

AGTC_2lite is developed in Basic. The .exe file is compiled with the QB64 compiler.

AGTC_lite, a DOS Console program

The AGTC_lite DOS Console program is developed in Basic. The .exe file is compiled with the QB64 compiler.
Note the update from release v1.52 to v1.53 which now holds improved test for length of FFtab files. With v.1.55 it also shows the name of the engaged with FFTab file in its window frame header. Which is welcome for documentation in form of screenshots.

We discovered on 18th of March, 2018 that in case of
feeding the program with an FFTab produced by 4nec2 with a comma as decimal mark,
the program delivered wrong values. However there was and is no problem using
EZNEC produced FFTab files with either comma or dot.

Hence this new release v1.56 which fixes the bug.
Of course this new release works fine with 4nec2/dot and EZNEC/dot or comma!

AGTC_lite - DEMO -

which show that DJ9BV was 100% correct in 1987 and AGTC_lite is THE program to use

AGTC

AGTC_lite.xlsx/xls :     Antenna G/T Calculation Microsoft Excel

An MS Excel® Sheet that computes an Antennas max. Gain, Average Gain, Temperature and G/T

AGTC.xlsx/xls:     Antenna G/T Calculation Microsoft Excel with matrix rotation

An MS Excel® Sheet that computes an Antennas max. Gain, Average Gain, Temperature and G/T

azel:     Antenna G/T Microsoft Excel® FFTab Loader (Basic Program)

Iso-FFtab:     Far Field Table of Ideal Isotropic Antenna

73, Hartmut, DG7YBN