An aftermarket radio interface module is a replacement RF module designed for the JR module bay—a standardized 5-pin interface delivering regulated 6V power, raw battery voltage, and a PPM signal carrying stick positions and channel data. These modules replace outdated 27/35/72MHz systems with modern 2.4GHz technology, requiring no internal modifications to the transmitter.
Many JR owners (PCM9XII, 9303, 9XII) face a common problem: their vintage radio cannot communicate with modern 2.4GHz receivers. Replacing the entire transmitter is expensive and sacrifices the legendary JR gimbal feel. The solution is simple—install a new 2.4GHz module into the existing JR module bay.
The JR transmitter outputs a PPM signal via the 5‑pin connector.
The module’s microcontroller reads the PPM signal.
The RF chipset encodes control data into a 2.4GHz protocol (DSMX, FrSky, FlySky, etc.).
The RF chip transmits to a compatible receiver.
The module bay provides: Ground, regulated 6V, raw battery voltage, and PPM input. Any replacement module must support 4.5V–8.4V operation.
All modules are SPI‑controlled, compatible with Arduino/STM32, and ideal for JR replacement projects.
| Module | Chipset | Output Power | Key Features | Best For |
|---|---|---|---|---|
| N210AP / N201AP | TI CC2500 | +1dBm | Ultra‑low cost, low power (18mA TX), Arduino‑friendly | Single‑protocol, DIY |
| N704AS | TI CC2652R+CC2592 | +22dBm (~150mW) | Multi‑protocol (Zigbee/BLE/Thread), 160mA TX | Multi‑protocol, telemetry |
| N407AS | Semtech SX1280 | +22dBm (~150mW) | LoRa®/FLRC/GFSK, -132dBm sensitivity, ranging | Max distance, interference immunity |
N210AP (CC2500) – Low‑cost workhorse
Data rate: 1.2–500 kbps; Modulation: OOK, 2‑FSK, GFSK, MSK
RX current 13.3mA, TX current 18mA @ +1dBm
Sensitivity -104dBm @ 2.4kbps, sleep 400nA
Supports DSMX, FrSky D8/D16/XJT, FlySky AFHDS2A, Futaba SFHSS, etc. via open‑source Multi‑Protocol firmware
N704AS (CC2652R+CC2592) – Multi‑protocol high power
Zigbee 3.0, Bluetooth 5.2 LE, Thread, 6LoWPAN
TX current 160mA @ +22dBm, RX 9mA, sensitivity -102dBm @ 250kbps
Range >500m line‑of‑sight, dimensions 35×18×3mm
N407AS (SX1280) – Maximum range & reliability
LoRa® (‑132dBm @62.5kbps), FLRC (2Mbps), GFSK
Output +22dBm, ranging engine for distance measurement
Dimensions 29×21×3mm, IPEX antenna
30–50% longer range than typical 2.4GHz modules
| Scenario | Recommended Module | Expected Performance |
|---|---|---|
| Single‑protocol (DSMX/FrSky) | N201AP/N210AP | 1km+ range, low power |
| Multi‑protocol universal | CC2500 + companion chips | 70+ protocols, flexible |
| Long‑range / FPV racing | N407AS (SX1280) | 2–3km+, excellent multipath |
| Telemetry / multi‑protocol gateway | N704AS | Long range, data telemetry |
Coral RF provides:
Samples & dev boards for N201AP, N210AP, N704AS, N407AS
Reference schematics (JR 5‑pin → SPI, voltage regulation)
Driver code for CC2500 & SX1280 (Arduino, STM32 HAL, bare‑metal)
RF test reports (sensitivity, current, compliance)
Customization: shielding, PCB dimensions, logo, pre‑flashed firmware
All products are RoHS & HF compliant.
Complete portfolio: 1dBm to +22dBm, CC2500 to SX1280 to CC2652R
JR‑bay ready: 2.0–3.6V operation with LDO; safe from 6V JR power
Open‑source friendly: drivers & community support
Customization available
| Order Model | Chipset | Frequency | Power |
|---|---|---|---|
| N210AP-2400M | CC2500 | 2400–2483MHz | +1dBm |
| N704AS-CC2652R-2400M | CC2652R+CC2592 | 2400–2500MHz | +22dBm |
| N407AS-2400M | SX1280 | 2400–2500MHz | +22dBm |
Website: www.coralradio.com
Contact: info@coralradio.com