RadioMaster GX15 Review: Top-Mounted 3.5" IPS Touchscreen & True Gemini ExpressLRS
Departing from traditional bottom-screen ergonomics, RadioMaster's newest flagship introduces a high-visibility top display, STM32 H7 processing power, CNC AG02 Hall gimbals, and native dual-transceiver Gemini telemetry.
- Top-Mounted 3.5" IPS Touchscreen: Relocating the display above the gimbals resolves the classic neck-strain issue and prevents thumbs or pinch-grips from obscuring telemetry widgets.
- Native Gemini ExpressLRS: Internal dual Semtech transceivers broadcast synchronized control packets on alternating channels concurrently, maintaining link quality during aggressive aircraft banking.
- STM32 H7 Compute Engine: High-clock processing ensures instantaneous EdgeTX UI navigation, zero-lag model switching, and real-time audio voice telemetry.
- Internal 250mW RF Limit: Built-in RF module delivers up to 250mW with internal active cooling fan; full-size rear JR module bay accepts high-power 1W–2W external modules for extreme long-range flights.
- GX15 Standard vs MAX: The MAX version steps up from composite plastic and V6 gimbals to CNC-milled aluminum AG02 Hall gimbals, carbon fiber pattern faceplates, and leather side grips.
SHENZHEN & AUSTIN — For nearly a decade, the industrial layout of high-end radio transmitters remained largely frozen in time. Radios placed their primary display screens near the base of the transmitter, directly beneath the pilot's palms and lanyard straps. With the official rollout of the RadioMaster GX15 and GX15 MAX, that legacy blueprint has been thoroughly reconsidered.
By mounting a bright 3.5-inch IPS color touchscreen at the top apex of the chassis, the GX15 allows pilots to check battery voltages, RSSI dBm values, and GPS coordinates with a micro-second glance that requires zero chin-dropping or hands repositioning.
“When flying high-speed line-of-sight fixed-wing or checking battery telemetry between freestyle packs, having the screen elevated above your sticks changes the entire ergonomic relationship with the radio.”
Dual-Transceiver ExpressLRS Gemini Architecture
Under the hood, the GX15 incorporates dual Semtech SX1281 2.4GHz transceivers operating in synchronized ExpressLRS Gemini mode. Unlike traditional antenna diversity—which switches between two antennas on a single receiver chip—Gemini transmits duplicate packets simultaneously across two distinct radio frequencies.
In competitive environments crowded by multiple digital video systems and Wi-Fi pollution, this dual-channel concurrency delivers unprecedented link robustness, eliminating sudden packet-rate throttling when an aircraft enters high-alpha bank angles where carbon fiber shields one antenna.
Ergonomics and Build: Standard vs MAX
The GX15 is offered in two configurations. The base model features high-precision V6 Hall sensor gimbals and a durable matte polymer shell. The GX15 MAX upgrades the experience with full CNC-machined AG02 red-anodized Hall gimbals, customizable stick tension, a carbon fiber faceplate, and textured leather hand grips.
Both models feature built-in gyroscopes, an integrated microphone for voice commands, haptic vibration feedback, USB-C charging, and a standard micro-SD slot alongside internal high-speed flash memory.
Technical Specifications Summary
- • Operating System: EdgeTX (native touch support)
- • Processor: STMicroelectronics STM32 H7 high-frequency MCU
- • Screen: 3.5" IPS Full-Color Touchscreen (480x320)
- • Internal RF: ExpressLRS 2.4GHz Gemini True Diversity (250mW max output)
- • External Bay: Standard Micro/JR Module Bay (Crossfire, ELRS 1W/2W, Multi-module)
- • Gimbals: V6 Hall Effect (Standard) / AG02 CNC Metal Hall (MAX)
- • Power Supply: 2x 18650 or 2x 21700 Li-ion cells with 2S balance charging