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Description
RadioMaster XR4 ELRS Receiver User Manual
Product Description:
The XR4 Receiver is a next-generation, true diversity dual-band ExpressLRS receiver, engineered for maximum reliability, range, and responsiveness. Featuring dual Semtech LR1121 RF transceivers, it supports both 2.4GHz and 900MHz Sub-G frequencies and leverages the ExpressLRS Gemini Xrossband (Gem-X) protocol for unmatched RF performance.
With two fully independent RF circuits and dual T-type antennas, the XR4 provides exceptional reception sensitivity, superior link stability, and versatile operation—whether in single-frequency Gemini mode or Xrossband dual-band mode. Its compact design and minimal weight make it ideal for long-range drones, FPV quads, and fixed-wing aircraft where signal integrity is critical.
The integrated Wi-Fi module enables fast and easy firmware updates and configuration via WebUI, accessible from your mobile device or PC—no cables or drivers required.
Whether flying in dense RF environments or pushing the limits of distance, the XR4 delivers the most robust, ultra-low-latency RF link available.
Key Features:
True Diversity & Dual-Band operation (2.4GHz + 900MHz Sub-G)
ExpressLRS Gemini & Gemini Xrossband (Gem-X) protocol support
Compatible with ELRS 2.4GHz, Sub-G 900MHz, Gemini, and Gem-X modes
High-performance ESP32D4 MCU for fast processing
Dual Semtech LR1121 RF transceivers for unmatched link stability
Secondary UART port for telemetry or extended functionality
Castled pads for easier soldering and reliable connections
Built-in Wi-Fi module for WebUI configuration and wireless firmware updates
Specifications:
Product: XR4 Gemini Xrossband Dual-Band Receiver
MCU: ESP32D4
RF Chips: Dual Semtech LR1121
RF Connectors: IPEX-1 × 2
Antennas: Dual-Band T-type × 2 (included)
Frequency Range: 2.4GHz / Sub-G 900MHz
Telemetry Power: 100mW
Max Refresh Rate: DK500Hz / K1000Hz
Min Refresh Rate: 50Hz
Working Voltage: DC 4.5V – 8.4V
Weight: 1.7g (without antennas)
Dimensions: 22mm × 18mm × 4mm
Firmware: ExpressLRS v3.5.1 (pre-installed)
Firmware Target: RadioMaster XR4 2.4/900 Gemini RX
Bus Interfaces:
– CRSF
– UART
Package Includes:
1 × XR4 Gemini Xrossband Dual-Band ExpressLRS Receiver
2 × Dual-Band T-Type Antennas
1 × CRSF Connection Wire
3 × Heat Shrink Tubes
1 × Manual
