The Radiomaster XR4 receiver supports operation in 2.4GHz and Sub-G 900MHz bands, using the ExpressLRS Gemini Xrossband (Gem-X) protocol. Equipped with two independent LR1121 transceivers, it ensures stable communication thanks to true diversity reception. Two operating modes allow it to be used in single-frequency or dual-band mode, depending on needs. The integrated Wi-Fi module simplifies firmware updates and configuration via WebUI. The receiver has low latency and a high refresh rate, which improves drone controllability. Dual T-antennas provide high reception sensitivity and signal reliability. An additional UART port expands connectivity and integration options.

Features

• Compatible with ExpressLRS 2.4 GHz, Sub-G 900 MHz, Gemini, and Gemini Xrossband (Gem-X)
• Built-in high-performance ESP32D4 microcontroller
• Uses a dual-channel Semtech LR1121 transceiver
• Additional UART port for extended functions
• Curved pads for easy soldering

Specifications

• MCU: ESP32D4
• RF chip: LR1121x2
• RF connector: IPEX-1x2
• Frequency range: 2.4GHz/Sub-G 900MHz
• Telemetry power: 100mW
• Maximum reception refresh rate: DK500Hz/K1000Hz
• Minimum receiver refresh rate: 50Hz
• Operating voltage: DC 5.0V-12.6V
• Firmware version: ExpressLRS v3.5.1 (pre-installed)
• FW Target: RadioMaster XR4 2.4/900 Gemini RX
• Antenna: 2 dual-band T-antennas (included)
• Bus interface 1: CRSF
• Bus interface 2: UART
• Size: 22*18*4mm
• Weight: 1.7g (without antenna)

Package contents

• 1 x XR4 Gemini Xrossband Dual-Band receiver
• 2 x dual-band T-antenna 2.4GHz/900MHz
• 1 x CRSF wire
• 3 x heat shrink tube
• 1 x user manual