XR4 Gemini Xrossband Dual-Band ExpressLRS Receiver EU-LBT

The XR4 is a true diversity ExpressLRS receiver with two Semtech LR1121 transceivers. It covers 2.4 GHz and Sub-GHz 900 MHz and runs Gemini single-frequency or Xrossband dual-band mode on the same board.

Built-in WiFi with a web UI lets you configure the receiver and update firmware from a PC or phone. A secondary UART port and castellated pads cover extended builds.

Modes and antenna mapping:

• Gemini 2.4 GHz: antenna 1 and antenna 2 on 2.4 GHz
• Gemini Sub-GHz: antenna 1 and antenna 2 on 868/915 MHz
• Gemini Xrossband (Gem-X): antenna 1 on 868/915 MHz, antenna 2 on 2.4 GHz

Features:

• True diversity with two Semtech LR1121 transceivers
• 2.4 GHz, Sub-GHz 900 MHz, Gemini and Xrossband (Gem-X) support
• Switchable between Gemini single-frequency and Xrossband dual-band mode
• 100 mW telemetry RF power
• Secondary UART port
• Castellated pads for soldering
• Compatible with ExpressLRS transmitters and modules on the matching band

Specifications:

• Item: XR4 Gemini Xrossband Dual-Band Receiver
• MCU: ESP32D4
• RF chip: Semtech LR1121 x 2
• RF connector: IPEX-1 x 2
• Antenna: Dual-band T antenna x 2
• Frequency range: 2.4 GHz / Sub-GHz 900 MHz
• Telemetry power: 100 mW
• Maximum packet rate: DK500Hz / K1000Hz
• Minimum packet rate: 50 Hz
• Working voltage: DC 4.5 to 8.4 V
• Weight: 1.7 g (without antenna)
• Dimensions: 22 x 18 x 4 mm
• Firmware: ExpressLRS v3.5.1 pre-installed
• FW target: RadioMaster XR4 2.4/900 Gemini RX
• Bus interface: CRSF
• Extend interface: UART

Includes:

• 1x XR4 Gemini Xrossband Dual-Band ExpressLRS receiver
• 2x dual-band T antenna
• 1x CRSF wire
• 3x heat-shrink tube
• 1x manual card