RadioMaster GX12 Gemini-X Dual-Band ExpressLRS Radio Controller (M2) EdgeTX 2.4GHz/900MHz

Overview

RadioMaster GX12 is a dual-band Gemini-X radio controller (M2) built around open-source EdgeTX and ExpressLRS for RC models, robotics, and other multi-channel control applications. It combines dual-band ExpressLRS operation (2.4GHz and Sub-G 900MHz) with a compact folding-antenna design, CNC aluminum digital gimbals, and internal flash storage.

Launch Video

Key Features

• Dual 1W (dual 1,000mW) dual-band XROSSBAND ExpressLRS RF
• Uses 2 third-generation Semtech LR1121 RF transceivers (2.4GHz, 900MHz and Gemini-X in one radio)
• Integrated foldable dual-band antennas (2.4GHz / 900MHz)
• GX01 digital 1000Hz 12-bit gimbals with EdgeTX sync
• CNC aluminium gimbal construction, 3D digital Hall effect sensors, quad ball bearings
• Folding gimbal sticks for compact transport
• High-contrast 128 x 64 monochrome OLED display
• 512MB high-speed internal flash memory (no TF card required)
• Single USB-C interface: charging, data transmission, simulator connectivity, firmware updates, and direct access to internal flash memory
• Modular/removable switch panels; switch delete plugs included
• SMA ports for DIY antenna modifications
• Six customizable RGB buttons; programmable 6-position switch and RGB indicators on 6-position and SA/SD switches
• Cooling fan and advanced cooling system for high-power RF operation
• Engineered for harsh conditions: hydrophobic PCB coating and extra rigid plastics

Specifications

Compatibility

• ExpressLRS installed as standard
• Compatible with all ExpressLRS receivers, including:
  • 2.4GHz (SX128x): RP Series, ER Series
  • 900MHz (SX127x): BR Series
  • 2.4GHz & 900MHz Gemini Xrossband (Gem-X) (LR1121): DBR4
• GX12 is now compatible with mLRS

Gimbal Adjustment

• A (L-R Mode-1 and Mode-2): Turn clockwise to disable self-centering (throttle) / Turn counterclockwise to enable self-centering (elevator)
• B (Up-Down tensions adjustment): Turn clockwise to increase vertical stick tension / Turn counterclockwise to decrease tension
• C (Left-Right tension adjustment): Turn clockwise to increase horizontal stick tension / Turn counterclockwise to decrease tension
• D (Throttle stick tension adjustment): Turn clockwise to increase throttle stick tension / Turn counterclockwise to decrease tension
• Upper and lower angle travel (38-60 degrees): Adjust the screw clockwise and the angle becomes smaller; adjust counterclockwise to increase the angle

Note: GX12 ships with the low tension gimbal spring installed.

What’s Included

• 1 x GX12 Radio Controller
• 1 x Signature Carry Case
• 1 x 18650 Battery Tray
• 2 x Replacement Switch Panels
• 6 x Switch Delete Plugs
• 1 x Type-C Cable
• 1 x Screen Protector
• 1 x 1.5mm Hex Wrench
• 4 x High Tension Gimbals Springs
• 1 x 2 Position Switch
• 1 x Momentary Switch
• 1 x RadioMaster Sticker Set
• 1 x GX12 Manual

For product selection, setup help, or after-sales support, contact support@rcdrone.top or visit https://rcdrone.top/.

Downloads

• GX12 Radio User Manual (PDF)
• ExpressLRS documentation
• mLRS project / mLRS Web Flasher

Details

A compact EdgeTX transmitter built around Gemini‑X ExpressLRS, combining 2.4GHz and 900MHz in one dual‑band radio.

Dual third‑generation Semtech LR1121 transceivers power 2.4GHz, 900MHz, and Gemini‑X operation from the internal RF.

Foldable antennas keep the controller travel-friendly while supporting both 2.4GHz and Sub‑G 900MHz links.

GX01 digital gimbals deliver a fast 1000Hz feel with CNC alloy construction, Hall sensors, and quad ball bearings.

Folding gimbal sticks reduce bulk for packing the transmitter into a backpack or case.

Key hardware highlights include the monochrome OLED, 512MB internal flash, SMA antenna ports, and customizable RGB buttons.

A single USB‑C port handles charging, data transfer, simulator use, firmware updates, and access to internal storage.

Smart active balance charging supports 2S packs to help prevent overcharging and extend battery life.

Modular switch panels and delete plugs make it easy to tailor the top layout to your preferred switch setup.

Built for harsh use with hydrophobic PCB coating, rigid plastics, and an internal cooling system for high-power RF.

What comes in the box includes the GX12 transmitter, carry case, battery tray, switches, panels/plugs, and USB‑C cable.