Top
RC receiver · FD-RX-GEMINI
Fiodel Gemini Dual-Band ELRS Receiver
Two LR1121 radios, 2.4 GHz and 900 MHz, true diversity on a 22 × 22 mm board.
Pre-order — ships from end of November 2026
- Full refund if you cancel any time before dispatch
- 6-month warranty against manufacturing defects
- GST invoice with every order
- Two Semtech LR1121 radios — true diversity
- 2.4 GHz and 900 MHz on each radio
- Gemini, dual-band Gemini Xrossband and all single-band modes
- RFX2401C PA + LNA per radio on 2.4 GHz
- Shared 32 MHz TCXO
- 22 × 22 mm, JST-SH plug and solder pads
Questions before you order? Ask us on WhatsApp
Overview
The Fiodel Gemini is a dual-band, true-diversity ExpressLRS receiver. Two Semtech LR1121 multi-band transceivers each drive their own antenna chain — a Skyworks RFX2401C PA/LNA and Johanson band-pass filter on 2.4 GHz, a Johanson integrated balun and harmonic filter on 900 MHz — joined onto one U.FL connector per radio by an SP3T RF switch.
With two complete radios it runs every ExpressLRS two-radio mode: Gemini on 2.4 GHz, Gemini on 900 MHz, and Gemini Xrossband with one radio on each band at the same time. Every single-band mode works too.
Both radios share one 32 MHz temperature-compensated oscillator. An ESP32-C3 runs the firmware and talks CRSF to the flight controller over a 4-pin JST-SH socket or four solder pads.
Specifications
Radio
| Protocol | ExpressLRS |
|---|---|
| Bands | 2.4 GHz and 900 MHz |
| Transceivers | 2 × Semtech LR1121 |
| Modes | Gemini (2.4 GHz), Gemini (900 MHz), Gemini Xrossband (2.4 GHz + 900 MHz), all single-band modes |
| 2.4 GHz front end | Skyworks RFX2401C PA + LNA and Johanson 2450FM07D0034 band-pass filter, per radio |
| 900 MHz chain | Johanson 0900PC16J0042 balun, match and harmonic filter, per radio |
| Antenna switch | Skyworks SKY13373 SP3T, per radio |
| Radio reference | 32 MHz TCXO, ±1.5 ppm, shared by both radios |
| Antennas | 2 × U.FL, each carrying both bands of its radio |
Controller
| MCU | Espressif ESP32-C3FH4, Wi-Fi |
|---|---|
| Wi-Fi antenna | On-board chip antenna |
| Output | CRSF serial |
| Status LED | WS2812 RGB |
| Button | Boot |
Power
| Input | 5 V |
|---|---|
| Regulator | TI TLV75733 3.3 V LDO, 1 A |
| 3.3 V rail load | About 0.15 A average, 0.35 A peak |
Board
| Size | 22 × 22 mm |
|---|---|
| Construction | 6-layer, 1.0 mm |
Pinout
J1Flight-controller plug (back)JST-SH 4-pin, 1.0 mm
Betaflight connector-standard serial pinout, peripheral side.
| Pin | Signal | Detail |
|---|---|---|
| 1 | 5 V in | |
| 2 | GND | |
| 3 | TX | Receiver → flight controller RX |
| 4 | RX | Receiver ← flight controller TX |
PadsSolder pads (front)4 pads
Same signals as the plug. Pads and plug are both fitted.
| Pin | Signal | Detail |
|---|---|---|
| 5V | 5 V in | |
| G | GND | |
| TX | TX | Receiver → flight controller RX |
| RX | RX | Receiver ← flight controller TX |
J2Antenna, radio AU.FL
| Pin | Signal | Detail |
|---|---|---|
| RF | Radio A | The 900 MHz antenna in Xrossband |
J3Antenna, radio BU.FL
| Pin | Signal | Detail |
|---|---|---|
| RF | Radio B | The 2.4 GHz antenna in Xrossband |
Questions
- What is the difference between this and the ELRS 2.4GHz Receiver?
- The ELRS 2.4GHz Receiver has one radio on one band. The Gemini has two complete radios that each work on 2.4 GHz and 900 MHz, so it can receive on two antennas, two frequencies or two bands at once.
- Can I use it as a plain 2.4 GHz receiver?
- Yes. It runs every single-band ExpressLRS mode as well as the two-radio modes.
- When will it ship?
- This is a pre-order. Shipping starts end of November 2026, in the order pre-orders were placed. You can cancel for a full refund any time before your order is dispatched.
