RadioMaster ER12 12-Channel PWM Dual-Band Gemini-X ELRS Receiver LBT

RadioMaster ER12 12-Channel PWM Dual-Band Gemini-X ELRS Receiver LBT

Product description

The RadioMaster ER12 is a high-performance 12-channel PWM ExpressLRS receiver with dual-band Gemini-X technology for RC airplanes, large-scale models, and demanding model-building applications. Thanks to the combination of 2.4 GHz and 868 MHz, the EU LBT version offers a reliable radio link with high immunity to interference and low latency.

With 12 amplified PWM outputs, two Semtech LR1121 radio chips, and a separate XT30 power connector, the ER12 is particularly well-suited for larger RC models with multiple servos and increased power requirements.

Dual-Band Gemini-X for Reliable Radio Connections

The ER12 supports ExpressLRS Gemini and Gemini-X with True Diversity. In Gemini-X mode, the receiver simultaneously uses the 2.4 GHz and 868 MHz frequency bands. Two independent radio chips improve reception reliability even under challenging radio conditions.

12 PWM Channels and Powerful Power Supply

The 12 amplified PWM outputs allow for the direct connection of numerous servos. The signal amplification ensures reliable transmission even with longer servo cables.

The separate XT30 connector allows the receiver and servos to be powered by a suitable power source. Additionally, CRSF and SBUS interfaces are available for further control and telemetry applications.

Comprehensive telemetry and easy configuration

The RadioMaster ER12 features three independent voltage measurements for monitoring the receiver power supply, the XT30 input, and an external battery voltage of up to 70 V.

Thanks to built-in Wi-Fi and a WebUI, settings and firmware updates can be conveniently performed. Rugged MMCX antenna connectors and a sturdy plastic housing facilitate integration into larger RC models.

Features

• 12-Channel PWM ExpressLRS Receiver
• EU LBT version for 2.4 GHz and 868 MHz
• Dual-band Gemini and Gemini-X support
• True Diversity with two Semtech LR1121 radio chips
• 12 amplified PWM servo outputs
• Separate XT30 power connector
• CRSF and SBUS support
• Bidirectional UART interface
• Three independent voltage telemetry channels
• External voltage measurement up to 70 V
• Telemetry transmission power up to 100 mW
• Wi-Fi configuration and firmware updates via WebUI
• Two rugged MMCX antenna connectors
• Compact plastic housing
• Ideal for RC airplanes, large-scale models, and multi-servo systems

Technical Specifications

General

• Manufacturer: RadioMaster
• Model: ER12 PWM Dual-Band Gemini / Gemini-X
• Variant: EU-LBT
• Part Number: RM0157.0141-LBT
• Product Type: 12-Channel RC Receiver
• Radio Protocol: ExpressLRS
• Frequency bands: 2.4 GHz / 868 MHz
• Diversity: True Diversity
• RF chips: 2× Semtech LR1121
• Microcontroller: ESP32-S3
• Required ELRS firmware: Version 4.1.0 or higher

Channels & Interfaces

• PWM Outputs: 12
• PWM signal amplification: Yes
• Serial Protocols: CRSF / SBUS
• UART connection: 4-pin JST-GH
• Antenna Connectors: 2× MMCX
• Wi-Fi / WebUI: Yes

Power Supply & Telemetry

• Input voltage: 5–12 V DC
• Separate power input: XT30
• Telemetry transmit power: Up to 100 mW, adjustable via LUA
• External voltage measurement (EXT-V): 4–70 V DC
• Receiver Power Supply Voltage Measurement (V-PWM): Up to 12 V
• XT30 voltage measurement: Up to 12 V

Dimensions & Weight

• Dimensions: 51 × 37.6 × 14.5 mm
• Weight: 22.5 g without antennas
• Antenna length: 250 mm