kv4p HT is an open-source hardware VHF or UHF radio designed to plug into the USB-C port of an Android smartphone and turn it into a handheld ham radio transceiver. It’s based on on ESP32 wireless module and a SA818 radio module. This accessory makes your phone capable of off-grid voice and text communication with a Technician-class amateur radio license. While you could build the kv4p HT by yourself since it’s an open-source hardware project, most people would likely purchased a Android smartphone ham radio kit on Halibut Electronics or Chelegance. We also use affiliate links in articles to earn commissions if you make a purchase after clicking on those links.