Radiolink R4FGM is a micro 4-channel receive

The Radiolink R4FGM is a micro 4-channel receiver featuring an integrated gyro, specifically designed for mini and micro-scale RC vehicles (like 1/28 or 1/64 builds, drift cars, and mini crawlers).   

Technical Specifications

 Dimensions: 25 mm × 13 mm (0.98" × 0.51")  

 Weight: 3 g (0.11 oz)  

 Antenna Length: 90 mm (3.54") (Note: Older production runs may feature a longer 200mm+ antenna wire)  

 Channels: 4 channels  

 Signal Output: PWM  

 Frequency: 2.4GHz ISM band (2400MHz ~ 2483.5MHz)  

 Spread Spectrum: FHSS (67-channel pseudo-random frequency hopping)  

 Channel Resolution: 4096 (0.25µs per section)  

 Operating Voltage Range: 3.0V to 10.0V DC (Supports High Voltage servos)  

 Operating Current: 30mA @ 5V (varies slightly based on input voltage)  

 RF Power: <10dBm  

 Control Range: Up to 400 meters (1,312 feet) on the ground  

 Operating Temperature: -30°C to 85°C  

 Safety Feature: Built-in reverse polarity protection (prevents damage if plugged in backward)  

Firmware & Response Speed (V2.0 / V2.1)

 Response Rates: 14ms (Default/FHSS V1 for analog servos). When paired via the FHSS V2 protocol on compatible transmitters (like the RC8X running firmware V1.1.5 or newer), response times can be selected down to 4ms or 3ms to take advantage of high-speed digital servos.  

 Note: Versions produced after April 26, 2023 (tagged V2.1) natively support these high-speed digital servo response modes.  

Integrated Gyro Modes

 Standard Mode (Default): Solid green LED indicator; outputs standard PWM without stabilization.

 Gyro Mode: Solid green + solid red LED indicator; stabilization activated.  

 Toggling the Gyro: Press the side ID SET button 3 times within 1 second to turn the gyro mode on/off.  

 Reversing Gyro Phase: Press the ID SET button twice within 1 second if the steering corrections are working backward. Gyro sensitivity can be fine-tuned remotely via a designated channel/switch on the transmitter.  

Transmitter Compatibility

Fully compatible with Radiolink surface and air transmitters utilizing their FHSS protocol:

 Surface Transmitters: RC8X, RC6GS (V1-V3), RC4GS (V1-V3)  

 Air/Stick Transmitters: T8S, T8FB, T12D, T16D