A young Namibian inventor named Simon Petrus recently built a prototype mobile phone that works without a SIM card or airtime, using radio-frequency (RF) technology instead of traditional cellular networks

🛠 How his invention works:Radio-frequency communication: Instead of depending on mobile carriers, his homemade device transmits calls directly via RF, much like a two-way radio .Repurposed components: He repurposed parts from old TVs, telephones, and expired SIM cards to assemble everything in a functional box-like device .Multi‑function gadget: The prototype also includes features like a built-in TV screen, LED light, fan, and USB charging ports, all powered by a single homemade circuit .

Timeline & recognition:Development period: He spent around two years creating the initial prototype, starting as a Grade 12 student (~2015–2017) .Awards won:

His innovation earned top honors in regional and national school science competitions in Namibia .Recent attention: Though the core development occurred years ago, the story resurfaced in mid‑2025 through media coverage highlighting its potential and ongoing challenges

.—In summary: Simon Petrus is the inventor behind this SIM‑free phone, which utilizes RF technology to enable free calling—an especially promising concept for communities without reliable cellular infrastructure.