1. The sBitx – The SDR for the homebrewer - https://www.vu2ese.com/index.php/2022/07/20/the-sbitx-the-sdr-for-the-homebrewer/
2. Loopantenna's - http://www.hvde.nl/electronica/diverse/loop/loop_nl.shtm
3. Digital SWR and power meter (Ч1, 2) - https://on7ir.blogspot.com/2021/05/digital-swr-and-power-meter-part-1.html
4. How to install a Mini Whip antenna - https://swling.com/blog/2020/10/how-to-properly-install-a-mini-whip-antenna-in-an-noisy-urban-environment/
5. 40m OCF Spiral Dipole - https://sergeev.io/projects/spiral-dipole/