Logo EU1KY Antenna Analyzer Modifications

Hardware Package

Smith Chart Screen
6M vertical scan on smith chart

This page is a description of the modifications I made to the open source/open hardware EU1KY antenna analyzer project. The FAA-450 Antenna Analyzer is built from a STM32-F7 Discovery board, a small RF board consisting of 2 direct conversion receivers fed from an RF bridge and a battery/power management board. The analyzer uses DSP techniques to analyze the 10kHz IF audio output from the direct conversion receivers to compute the complex voltage and current applied to the antenna port. From this, an OSL (Open/Short/Load) calibration is applied to give a complex impedance value for the antenna. From this impedance, VSWR may be calculated when referenced to 50ohms (other reference impedances are also supported). Kits or a built project are available from www.elekitsorparts.com This project originated from the EU1KY Antenna Analyzer V3, which features a 4.3" colour TFT LCD, capacitive touch screen, HF/VHF(UHF) frequency coverage, built-in TDR function, signal generator function and multiple scanning curves for impedance and VSWR measurements. Full open source software is available at bitbucket.org/kuchura/eu1ky_aa_v3. Development is by cross compiling for the STM32F746 board on windows (Embitz IDE) or linux (makefile with arm-none-eabi-gcc). The generated F7Discovery.bin file is uploaded to the device using ST-Link loader from STMicroelectronics. A hint for uploading: the device must be powered on and a mini USB cable must be plugged into the ST-LINK port on the device. Also, I ended up using a windows box for flashing the device as there are some reports that the linux version of ST-Link does not support the STM32F746 discovery board. For windows, you will need to get the STSW-LINK004 utility and STSW-LINK007 windows drivers from the above link.

List of Custom Software Modifications

Files / Downloads / Links

Free windows IDE for ARM: https://www.embitz.org/.
STMicroelectronics ST-Link software: https://www.st.com/en/development-tools/st-link-v2.html.
My binary image: F7Discovery.bin (665.1kB) analyzer image.
My project source files: eu1ky_aa_v3-16-aug-2018.zip (8.1Mb).
My project source files: eu1ky_aa_v3-6-sept-2018.zip (9.0Mb).
A new version based on the KD8CEC mods (adds S21, 1200Mhz+, beeper, rtc, FT8 and much more).
My project source files: antennaanalyzer_2019_sept_29.tar.gz(6.6Mb).
Latest binary image: F7Discovery_2019_sept_29.bin (597.1kB) analyzer image.
You can download John Coppens ON6JC/LW3HAZ excellent Linsmith program from http://jcoppens.com/soft/linsmith/index.en.php
My linsmith remote control patch: linsmith-remote.patch for linsmith-0.99.28 (19.2kB).
My 6M 50MHz antenna being measured above: http://ve7it.cowlug.org/6m-five-eigths.html .
Analyzer kit/assembled supplier: www.elekitsorparts.com

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