Radiomaster ER12 PWM Dual-Band Gemini ELRS Receiver

Overview:
The Radiomaster ER12 PWM Dual-Band Gemini is a 12-channel ExpressLRS receiver designed for larger fixed-wing aircraft, particularly builds using multiple servos, long servo leads or higher-current power systems. Its dual-band Gemini-X RF system uses 2.4GHz and sub-GHz 900MHz frequencies to provide a robust control link, while amplified PWM outputs help maintain signal quality across longer wiring runs.

Alongside its 12 PWM outputs, the ER12 provides serial connectivity for telemetry and other compatible peripherals. Three independent voltage-monitoring inputs allow the receiver supply, XT30 power input and an external battery voltage to be monitored separately. A dedicated XT30 power input supports installations with greater servo power demands, but passes the input voltage directly to the receiver's PWM power rail, so the voltage rating of connected servos must be checked carefully.

This is the LBT version, intended for compatible ExpressLRS transmitters and modules configured for the corresponding regulatory region. It is suited to larger fixed-wing models where a high channel count, flexible power monitoring and dual-band radio performance are important.

Features:
- Dual-band Gemini-X system: Uses 2.4GHz and sub-GHz 900MHz RF bands with dual Semtech LR1121 transceivers.
- Amplified PWM signals: Helps maintain signal quality with long servo leads and larger, high-torque servos.
- Three independent voltage-monitoring inputs: Supports simultaneous monitoring of the receiver supply, XT30 power input and an external battery.
- Dedicated XT30 power input: Provides a separate power connection for demanding servo installations. The PWM power rail follows the input voltage, so suitable servos or a regulated supply are essential.
- Wireless configuration and updates: Built-in Wi-Fi support allows configuration through the ExpressLRS WebUI and wireless firmware updates.
- Serviceable antenna connections: MMCX connectors allow the antennas to be disconnected or replaced.
- Designed for larger fixed-wing aircraft: Suits multi-servo installations and builds requiring numerous control channels.

Specification:
- Model: Radiomaster ER12 PWM Dual-Band Gemini Receiver
- Protocol: ExpressLRS
- RF transceivers: 2 × Semtech LR1121
- Frequency bands: 2.4GHz and sub-GHz 900MHz
- PWM outputs: 12 channels
- Serial output protocols: CRSF / SBUS
- Telemetry power: Up to 100mW, adjustable via Lua
- Receiver input voltage: 5.0–12.0V
- EXT-V voltage monitoring range: 4.0–70V
- V-PWM voltage monitoring range: Up to 12V
- XT30 voltage monitoring range: Up to 12V
- Antenna connection: MMCX
- Antenna length: 25cm
- Dimensions: 51.0x37.6x14.5mm
- Weight: 22.5g
- Required ExpressLRS firmware: Version 4.1.0 or later
- Region: LBT

Included:
- 1x Radiomaster ER12 PWM Dual-Band Gemini Receiver
- Accessories