Radiomaster XR4 Gemini Xrossband Dual-Band ExpressLRS Receiver

The Radiomaster XR4 Xrossband is a dual-frequency, dual-channel receiver from the Radiomaster brand, designed for maximum stable and long-range communication in FPV drones, wings, and airplanes. The device combines modern Semtech LR1121 RF chips, allowing simultaneous operation in the 2.4 GHz and Sub-G 900 MHz bands using the ExpressLRS Gemini Xrossband (Gem-X) protocol, ensuring a reliable signal even in challenging RF conditions.

This compact module features a low weight — 1.7 g without antennas — and dimensions of 22×18×4 mm, making the XR4 an ideal solution for racing platforms and miniature builds. Ultra-low latency and a reception refresh rate of up to 1000 Hz guarantee instantaneous control response, while the dual-channel diversity architecture ensures stable reception in the presence of interference or at long distances.

Key Features

• True diversity: two separate radio channels for enhanced signal reliability.
• ExpressLRS Gemini Xrossband (Gem-X) support: modern protocol for minimizing communication loss.
• Instant response: up to 1000 Hz telemetry/channel refresh rate.
• Built-in Wi-Fi module: wireless firmware updates and configuration via WebUI from a computer or smartphone without soldering.
• Two UART ports: extended connectivity and integration capabilities for complex systems.
• Castellated pads and dual output (CRSF/UART): simplify mounting and connection to the flight controller.

The XR4 supports both single-channel (Gemini) and full dual-channel (Xrossband) modes, giving the pilot flexibility in configuration for specific tasks: from high-speed FPV racing to long-range flights with enhanced communication stability.

Technical Details

• RF chips: Semtech LR1121 (dual)
• Bands: 2.4 GHz and Sub-G 900 MHz
• Protocol: ExpressLRS Gemini Xrossband (Gem-X)
• Refresh rate: up to 1000 Hz
• Interfaces: 2 × UART, CRSF/UART output
• Wi-Fi module: yes (firmware updates and WebUI)
• Dimensions: 22×18×4 mm
• Weight: 1.7 g (without antennas)

Package Contents

Included:

• 1 x XR4 Gemini Xrossband RX
• 2 x dual-band T-antenna
• 1 x CRSF wire
• 3 x heat shrink tubing

This receiver from Radiomaster is configured for quick integration: compact size and light weight allow the module to be placed in the tightest compartments, and the presence of two UART ports and a CRSF output makes it a versatile component for various flight controllers. The built-in Wi-Fi simplifies the pilot's life — updates and configurations are available without additional equipment.

Product category: Drones & Quadcopters > Receivers. Product ID: 17030.

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