AGTC (Antenna Gain / Temperature Calculator) is a numerical tool for the evaluation of Antenna G/T based on EZNEC/4nec2 generated far-field radiation pattern data (FFTab).
It follows the general principles described in the literature (notably DJ9BV, DUBUS 4/1987), using a full spherical integration of the antenna radiation pattern gain characteristic allocated with the averaged brightness temperatures of the sky and the ground.
Version 'Twain' is an extension of AGTC. It allows computation of two antenna FFTab files and Overall Receiver System G/T at 30 degrees of elevation acc. the DL9BV model for comparing antenna performance for EME. Either compute G/T for one antenna, compare two systems, or apply Convergence Correction (KF2YN) to one antenna.
This website runs Javascript to open and process a file from your harddrive.
Only execute this program from a safe and know source such as our URL on Github (https://f5fod.github.io/AGTC-JS/).

Tribute: A javascript based, single HTML file AGTC was first realised as ’AGTC Web Utility’ by BG5TOX & BG5ATV in 01/2026.

This software is provided "as is", without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and noninfringement.^*

In no event shall the author be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the software or the use or other dealings in the software.^*

The user assumes full responsibility for the use of this software and for any results obtained.

Note for users in the European Union: This is free software.
Liability is therefore excluded to the greatest extent possible. See also Directive (EU) 2024/2853 Liability for defective products.

By proceeding, you acknowledge that you have read and accepted this disclaimer.

• MIT License: Originating at the Massachusetts Institute of Technology, Cambridge, US, ~1987