How to stop Firefox from making automatic connections

 https://support.mozilla.org/en-US/kb/how-stop-firefox-making-automatic-connections

2.4 Ghz vs 5Ghz wifi

 https://www.digikey.hk/en/articles/compare-24-ghz-5-ghz-wireless-lan-industrial-applications

sl230 fix

rear break

https://ameblo.jp/tankoro2019/entry-12469163864.html