Description The ESP138 is a dual system radio utilizing the TEF6686 system open source project and the ESP32 SI4732 system architecture It integrates the TEF6686 chip with high fidelity Bluetooth functionality offering exceptional selectivity and ultra high sensitivity The SI4732 supports Air Band AIR and Single Sideband SSB as well as Bluetooth 5 0 dual mode Equipped with a 2 4 inch touchscreen numeric keypad large capacity battery and aluminum alloy body it offers both professional reception and portability Specification Controller ESP32 WROOM 32UBluetooth JL high performance chipScreen 2 4 inch IPS touchscreen 320x240 Speaker 40mm full range speakerAntenna Built in 820mm telescopic antennaExternal antenna port 3 5mm external antenna portBattery 3 7V 2500mAh lithium polymer batteryInterface Type C 5V 2A charging supports data upgrades Casing Material Aluminum AlloyDimensions 120 63 25mm excluding antenna Weight Approximately 350gFeatures 1 Dual System Reception The ESP138 is a dual system professional radio utilizing the TEF6686 system open source DSP algorithm and the ESP32 SI4732 system full band coverage operating independently While the radio is powered on a single click of the power button allows you to switch between operating systems Note The TEF6686 system supports open source firmware upgrades while the SI4732 system s firmware is locked and cannot be flashed 2 TEF6686 System The TEF6686 system supports FM LW MW