RadioMaster DBR4 Dual Band Xross Gemini ExpressLRS Receiver

Introducing the RadioMaster DBR4 Gemini Xrossband ExpressLRS — a new-generation dual-band receiver designed for FPV pilots and professional users who value reliable communication and flexible integration. The DBR4 supports simultaneous reception in the 2.4 GHz and 900 MHz bands, allowing for two independent data streams to enhance connection stability and interference protection. The receiver is optimized for use with the RadioMaster Nomad module and is compatible with modern flight controllers via the CRSF interface.

Key Advantages

Thanks to two separate Semtech LR1121 × 2 RF chips and a powerful ESP32 processor, the DBR4 ensures high sensitivity, fast telemetry processing, and stable ExpressLRS firmware operation. The telemetry transmitter has a high power output of up to 2 × 100 mW, guaranteeing reliable data transmission over long distances. The design includes four wire antennas (2 × 2.4 GHz and 2 × 900 MHz), allowing for optimal antenna placement on the aircraft for a specific frame or body.

DBR4 Gemini Xrossband ExpressLRS Technical Specifications

• Frequency Bands: 2.404 – 2.479 GHz and 903.5 – 926.9 MHz
• Max Telemetry Power: 2 × 100 mW
• Max Refresh Rate: 500 Hz (supports 1000 Hz in ExpressLRS V3.4)
• Min Refresh Rate: 50 Hz
• RF Chip: Semtech LR1121 × 2
• Processor: ESP32
• Power Supply Voltage: DC 4.5 – 8.4 V
• Weight: 2.70 g (without antennas) / 5.30 g (with antennas)
• Dimensions: 27.20 mm × 27.20 mm
• Interface: CRSF
• Pre-installed Firmware: ExpressLRS v3.3.2
• Mounting Holes: 20 × 20 mm
• Antennas: 2 × 2.4 GHz and 2 × 900 MHz wire antennas
• Support: GemX Xrossband
• Data Packets: New Sub-GHz and K-mod modes for high-speed transmission

The DBR4 is ideal for various scenarios: racing and freestyle flights, long-range FPV missions, and professional applications where the simultaneous presence of low-latency 2.4 GHz and high-penetration Sub-GHz channels is crucial. Two independent RF modules provide additional fault tolerance, and the ESP32 allows for advanced firmware features and updates. Thanks to CRSF, connection to transmitters and flight controllers is quick and seamless, while standard 20×20 mm mounting holes and compact dimensions facilitate integration into various frames.

Package Contents

• DBR4 Gemini Xrossband ExpressLRS Receiver
• 2 x 2.4 GHz wire antennas
• 2 x 900 MHz wire antennas
• 1 x CRSF cable
• 4 x 4mm red dampers
• 4 x 3mm black dampers
• User manual

Brand: Radiomaster. Product Category: Drones & Quadcopters → Drone Components → Drone Spare Parts → Receivers. If you need a reliable dual-band receiver with GemX Xrossband and ExpressLRS support, the DBR4 offers a modern solution with high telemetry power, dual Semtech RF chips, and support for new transmission modes for optimal performance.

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