Overview
The Spektrum SPM4651T DSMX SRXL2 Serial Receiver with Telemetry is a cutting-edge micro receiver designed for serious RC enthusiasts who demand professional-grade performance in compact, lightweight packages. This advanced receiver is particularly ideal for UK RC pilots flying helicopters, multi-rotor drones, and FPV systems where space and weight are critical considerations. Whether you are building a high-performance racing drone, a precision FPV quadcopter, or an advanced RC helicopter setup, this receiver delivers the reliability and functionality you need to take your flying to the next level.
Building on the success of its predecessor, the SPM4651T adds significant value and enhanced functionality compared to earlier models. This evolution represents Spektrum's commitment to providing RC enthusiasts in the UK and worldwide with receivers that combine cutting-edge technology with practical usability. The receiver integrates SRXL2 protocol technology, which is an open-source communication standard developed by Spektrum that enables blazing-fast serial data connections with support for up to 20 channels. This means you get exceptional control responsiveness and the ability to configure complex flight control systems entirely from your Spektrum transmitter, without needing separate programming devices or complicated setup procedures.
The SPM4651T represents a significant upgrade in the RC receiver market, offering features and performance levels previously found only in much larger, heavier systems. Its small, lightweight construction makes it the perfect choice for weight-conscious applications where every gram matters, yet it delivers full-range telemetry and remarkable control link range that rivals receivers many times its size.
Key Features
- SRXL2 Technology — This powerful open-source communication protocol developed by Spektrum provides blazing-fast serial data connections with up to 20 channels of control, delivering exceptional responsiveness and control precision for complex flight control systems and advanced configurations.
- Low Noise Amplifier — The integrated low-noise amplifier significantly reduces interference and produces extended control link range, ensuring reliable signal reception even in challenging RF environments with multiple radio sources operating simultaneously.
- Full Range Telemetry — Receive comprehensive telemetry data from your aircraft, including battery voltage, current draw, receiver signal strength, and other vital flight parameters, all transmitted wirelessly back to your Spektrum transmitter for real-time monitoring.
- Dual Diversity Antennas — Two independent antennas with intelligent diversity switching ensure solid, uninterrupted signal reception from any aircraft orientation, providing reliable control even during aggressive manoeuvres or in installations where carbon fibre, metal structures, or batteries might shield the antenna.
- Long Coaxial Antennas — The extended 100mm coaxial antenna design delivers maximum signal strength in all orientations, making this receiver exceptionally well-suited for challenging installations where conventional antennas would struggle to maintain a strong link.
- Wide Voltage Input Range (3.3V to 8.4V) — The receiver accommodates a broad range of power supply voltages, providing flexibility in battery selection and allowing use with various RC aircraft power architectures without requiring voltage regulators.
- Simple Bind Button — The convenient on-board bind button eliminates the need to carry separate bind plugs or receiver modules to pair your receiver with your Spektrum transmitter, streamlining the setup process at the flying field.
- DSMX 2.4GHz Protocol — Spektrum's proven DSMX RF protocol operates in the licence-free 2.4GHz frequency band and delivers remarkable range and interference-free performance, ensuring your RC aircraft maintains a solid control link in any flying environment.
- Programmable Configuration — Adjust receiver settings and failsafe behaviour directly from your Spektrum transmitter, allowing fine-tuning without additional programming equipment or software installation.
- Exceptionally Compact Design — Weighing just 4 grams with dimensions of 18mm width, 7.8mm height, and featuring dual diversity antennas, this receiver offers a size and weight that makes it ideal for heli, multi-rotor and FPV systems where compact electronics are essential.
Technical Performance
The SPM4651T DSMX SRXL2 Serial Telemetry Receiver represents a significant engineering achievement in miniaturised RC receiver technology. Operating on Spektrum's proven DSMX 2.4GHz RF protocol, this micro receiver delivers full-range control link performance with remarkable interference resistance. The integration of a low-noise amplifier provides extended control range compared to conventional receiver designs, making it suitable for long-range applications whilst maintaining the compact form factor demanded by weight-sensitive applications. The receiver's dual diversity antenna configuration with long coaxial antenna elements ensures exceptional signal reception in all aircraft orientations and challenging installation scenarios. The SRXL2 serial communication protocol enables bi-directional data exchange at speeds that deliver responsive, lag-free control with support for up to 20 individual channels. The wide input voltage range of 3.3V to 8.4V ensures compatibility with various battery configurations and power supply architectures used in modern RC aircraft. At just 4 grams, the receiver adds minimal weight whilst delivering performance and features previously found only in much larger receivers. The open-source nature of the SRXL2 protocol means flight controller manufacturers worldwide can implement native support, making this receiver compatible with virtually all modern FC platforms used in competitive racing and hobby applications throughout the UK and internationally. The full-range telemetry capability provides real-time feedback on system health, allowing pilots to monitor battery consumption, signal strength and other critical parameters throughout their flight.
What's in the Box
- SPM4651T DSMX SRXL2 Serial Receiver with Telemetry
- Instruction Manual
What You Need to Complete
- Spektrum DSMX 2.4GHz Transmitter (for binding and control)
- Power supply with voltage between 3.3V and 8.4V (suitable battery or voltage regulator)
- Flight controller or servo interface compatible with SRXL2 serial protocol (most modern flight controllers support this standard)
- Servo connectors or soldering equipment for wiring connections
Frequently Asked Questions
- What is SRXL2 protocol and why does it matter for my RC aircraft? — SRXL2 is an open-source communication protocol developed by Spektrum that enables fast, bidirectional data exchange between your receiver and flight controller over a single signal wire. This allows you to configure flight control parameters, receive comprehensive telemetry, and achieve much faster response times compared to traditional PWM-based receivers. Most modern flight controllers used in UK RC racing and hobby applications support SRXL2 natively.
- Is the SPM4651T suitable for FPV racing drones? — Yes, this receiver is specifically designed for FPV and multi-rotor applications. Its extremely compact size (18mm width, 7.8mm height) and light weight of just 4 grams make it ideal for weight-sensitive racing drones, whilst the dual diversity antennas ensure the rock-solid signal link required for high-speed racing manoeuvres.
- What voltage power supply do I need for this receiver? — The SPM4651T accepts input voltages between 3.3V and 8.4V, offering significant flexibility. You can power it from standard 1S to 2S LiPo batteries, or use a voltage regulator if drawing power from higher-capacity battery packs used in your aircraft.
- How does the full-range telemetry feature work? — The receiver continuously transmits telemetry data back to your Spektrum transmitter, providing real-time information about battery voltage, current draw, and signal strength. This allows you to monitor your aircraft's health throughout the flight and make informed decisions about landing before power becomes critical.
- Do I need a separate bind plug to pair this receiver with my transmitter? — No, the SPM4651T features a convenient bind button directly on the receiver, eliminating the need to carry separate bind plugs to the flying field. Simply press the bind button whilst powering on the receiver and it enters bind mode, ready to pair with your Spektrum transmitter.
- What is the advantage of dual diversity antennas? — The two independent antennas with intelligent diversity switching ensure that your receiver maintains a strong signal from virtually any aircraft orientation. This is particularly valuable during aggressive manoeuvres where one antenna might be shielded by the aircraft frame, carbon fibre components, or batteries. The system automatically selects the antenna with the strongest signal, ensuring uninterrupted control.
- Can I use this receiver in carbon fibre aircraft? — Yes, the long coaxial antenna elements (100mm length) are specifically designed to provide maximum signal strength even in challenging installations where carbon fibre, metal structures, and batteries might shield conventional antennas. The dual diversity configuration ensures excellent reception regardless of aircraft construction materials.
- How many channels does this receiver support? — The SPM4651T supports up to 20 channels via the SRXL2 protocol, providing far more control channels than the 8-16 channels supported by conventional PWM receivers. This makes it suitable for complex aircraft with multiple controllable systems.
- Is this receiver water-resistant? — The receiver is not rated as water-resistant, so avoid exposing it to moisture or splashing water. This is typical for most RC receiver designs and should not pose an issue for normal flying operations in dry weather conditions.
- What is the difference between this SPM4651T and the earlier SPM4649T model? — The SPM4651T builds on the SPM4649T foundation by adding more value, enhanced functionality, longer control link range, and improved telemetry performance. The new model incorporates the proven SRXL2 technology with its advanced features, making it a significantly more capable receiver for modern RC applications.
Why Buy from RC Model Shop?
RC Model Shop is a trusted UK RC retailer and authorised dealer for all the brands we stock, including Traxxas, ARRMA, Losi, FTX, Hobbywing, Spektrum and more. Based in Walsall, we have a physical store where customers are welcome to come in, view products and purchase in store. Whether you are a seasoned competitor, a weekend basher, or just discovering the world of RC for the first time, our team of experienced RC enthusiasts is here to help you find the perfect setup and provide ongoing support. Order the SPM DSMX SRXL2 Serial Receiver with Telemetry P-SPM4651T today with confidence, knowing you are buying from an authorised retailer with genuine products, expert knowledge and a commitment to customer satisfaction. Shop online or visit us in Walsall — we look forward to helping you get the most out of your RC experience.
