Introduction
The FUTABA R7308SB is a high-performance 2.4GHz FASSTest bidirectional communication system receiver, designed for aircraft models. It features S.BUS2 and S.BUS ports, along with 8 channels for conventional systems, offering advanced telemetry capabilities and simplified wiring for compatible systems.
Video: Overview of the Futaba R7308SB receiver's features and design.
Specifications
| Feature | Detail |
|---|---|
| Receiving Frequency | 2.4GHz FASSTest Transceiver System |
| Power Requirements | 3.7V - 7.4V (or electrically adjustable/independent BEC) |
| Voltage Range | 3.5V - 8.4V |
| Current Loss | 75mA |
| Dimensions | 40mm x 25mm x 15mm (0.98 x 1.53 x 0.56 inches) |
| Weight | 11g (0.39oz) |
| Channels | S.BUS2 / S.BUS Port and 8 Channels for Conventional System |
| Antenna Type | Sleeve antenna, dual diversity system |
| Material | Composite Material |
| Recommended Age | 14+ years |
| Batteries Included | No |
The R7308SB receiver is compatible with FUTABA 14SG, 16SZ, 18SZ, 18MZ, and other FASSTest remote controls.
Image: The R7308SB receiver weighing 11 grams.
Image: Dimensions of the R7308SB receiver (40x25x15mm).
Setup
Antenna Installation
The R7308SB has two antennas to maximize signal reception and provide a diversity antenna system. Ensure the two antennas are placed at 90 degrees to each other for optimal performance.
- You must leave 30mm at the tip of the antenna fully exposed. If the exposed antenna should be secured so that it cannot move around, bend back inside your aircraft.
- Do not cut or bundle the receiver antenna wire.
- The antennas must be mounted in such a way as to assure they are strain relieved.
- Keep the antenna as far away from the motor, ESC, and other noise sources as you possibly can.
- Do not touch the antenna to metal, carbon, or other conductive material.
Image: Diagram illustrating proper antenna installation at 90 degrees and general precautions.
Power Connection
The receiver requires a power supply of 3.7V to 7.4V. It is recommended to use an ESC (Electronic Speed Controller) to regulate the power supply to avoid direct battery connection, which could lead to reverse polarity damage. The voltage range is 3.5V to 8.4V.
Connector Definition
Generally, the signal line is located near the positive terminal, with the positive terminal in the middle and the negative terminal on the ground. Do not connect a connector as shown in the figure to avoid short-circuiting.
Typical Installation
The R7308SB supports S.BUS2 and S.BUS for simplified wiring, especially with systems like Microbeat, HC3X, and VBar. The diagram below illustrates a typical setup.
Image: Typical installation diagram showing connections for servos, battery, switch, HUB, S.BUS2 port, and various sensors.
Operating Instructions
Linking the Receiver to the Transmitter
To establish communication between the R7308SB receiver and your FASSTest compatible transmitter, follow these steps:
- Turn on the receiver. (Transmitter is always OFF)
- Press and hold the SW (switch) for 5 seconds to link. The LED will blink RED → ORANGE → GREEN → ORANGE (slow blink).
- Release the switch. The LED will blink ORANGE once.
- Press the switch again. The LED will blink ORANGE twice.
- Press and hold the SW. The LED will blink ORANGE.
- Release the SW. The LED will turn solid ORANGE.
- Turn off the receiver power.
After restarting, the LINK LED should light up solid ORANGE, indicating a successful link.
Dual Rx Link System
For dual receiver setups in an aircraft, one receiver can become unable to communicate, while the other receiver remains operational. This system ensures redundancy.
- Turn on the receiver. (Transmitter is always OFF)
- Press and hold the SW for 5 seconds or more.
- Release the switch here.
- Press SW once more to return to flashing orange once.
- Press switch.
- Blinks GREEN twice.
- Press and hold the SW.
- Blinks ORANGE.
- Release SW.
- Solid ORANGE.
In Dual Rx Link mode, the SB2/RX port is for reception only. Use CH mode B, C, D, F, G mode for S.BUS output and S.BUS2 input/output.
Image: Instructions for setting up the Dual Rx Link System and a connection example.
Telemetry Mode (FASSTest 12CH)
The R7308SB supports FASSTest 12CH telemetry. You can switch telemetry ON or OFF.
- Telemetry OFF: Turn on the receiver (transmitter OFF). Press SW once more to return to flashing orange. Press SW. Blinks ORANGE twice. Press and hold SW. Blinks ORANGE. Release SW. Solid ORANGE.
- Telemetry ON: Turn on the receiver (transmitter OFF). Press SW once more to return to flashing orange. Press SW. Blinks ORANGE twice. Press and hold SW. Blinks ORANGE. Release SW. Solid ORANGE.
After linking, the receiver will transmit telemetry data to the transmitter. The transmitter will display the telemetry of the main receiver. For a second-linked receiver, the transmitter will show 'Telemetry OFF' for the second link.
Channel Modes
The R7308SB is capable of changing its channel allocations as described in the table below. This is especially important when using the receiver in a dual receiver mode. See your transmitter operation manual for complete details on operating in the dual receiver mode.
Image: Detailed instructions for linking, telemetry mode settings, and a table of channel modes.
Maintenance
- The R7308SB receiver should be protected from vibration by foam rubber, Velcro, or similar mounting methods.
- Protect from moisture and extreme temperatures.
- Regularly inspect all connections for secure fit and signs of wear.
- Keep the receiver clean and free from dust and debris.
Troubleshooting
LED Indication Status
| Status | LINK LED |
|---|---|
| No signal reception | Red Solid |
| Receiving signals | Green Solid |
| Waiting for link | Start → Green/Red (1 second) |
| Unrecoverable error (EEPROM, etc.) | Alternate blink |
In Dual Rx Link Mode
| Status | MODE LED |
|---|---|
| External receiver is not connected or not connected (S.BUS signal not received) | Red Solid |
| S.BUS signal received from external receiver (also received by external receiver) | Green Solid |
Link Precautions
- Do not perform the linking procedure while the motor's main switch is ON or the engine is operating, as it may result in serious injury.
- When the linking is complete, please cycle the receiver power to ensure the receiver is properly linked to the transmitter.
- If the R7308SB receiver was previously linked to another transmitter, make sure that the transmitter is not operating while linking the receiver to the new transmitter.
User Tips
- For simpler wiring, especially with complex setups, utilize the S.BUS2 system as it only requires one data cable to connect to compatible flight controllers like Microbeat, HC3X, or VBar.
- Take advantage of the telemetry features by connecting optional telemetry sensors to the S.BUS2 port. This allows direct display of critical data like power voltage on your remote control, enhancing flight safety and monitoring.
- Always ensure proper power supply through an ESC or independent BEC to prevent damage from reverse polarity.
Warranty and Support
For warranty claims or technical support, please contact the original seller or the manufacturer directly. Keep your proof of purchase for any warranty-related inquiries.
