Features
- SRXL2 Technology
- Small, Lightweight and Perfect for the DIY Enthusiast
- Wide Voltage Input Range
- Fly-By Telemetry
- Dual Diversity Antennas
- Bind Button installed for Easy Binding
Overview
The SPM4650 DSMX SRXL2 Serial Micro Receiver takes the original SPM4648 receiver and adds more value, functionality and fly-by telemetry, while decreasing the size and weight of the already micro sized Spektrum serial receiver. The SPM4650 uses our feature-rich SRXL2 protocol to give pilots a blazing fast serial data connection with up to 20 channels. SRXL2 is a powerful communication protocol that improves bi-directional communication between the radio system and flight controller for added telemetry functionality and flight control configuration right from the pilots Spektrum Transmitter*, all over one signal wire.
The SPM4650 is small, lightweight, and customizable, providing an excellent receiver for even the smallest of applications. It also features a simple bind button so pilots no longer need to carry a separate receiver or bind plug to bind. Dual antennas provide receiver diversity for solid signal and the long coax antennas help to provide maximum signal strength in all orientations for challenging installations where carbon fiber, metal and batteries shield the antenna. And with Spektrum DSMX 2.4GHz RF protocol the Spektrum SRXL2 Serial Micro Receiver provides remarkable range and interference free performance.
What's in the Box?
- (1) SPM4650 Receiver
- (2) U.FL Antenna
- (1) 6" Receiver Extension Cable
- (1) 4-Pin Connector
- (1) Product Manual
- Clear Heat Shrink Wrap
Overview
The SPM DSMX SRXL2 Receiver with Connector Installed (P-SPM4650C) represents the latest evolution in Spektrum's receiver technology, offering a compact and powerful solution for RC enthusiasts throughout the UK looking to upgrade their systems. This advanced serial micro receiver combines cutting-edge SRXL2 protocol technology with the proven reliability of DSMX 2.4GHz RF communication, making it an ideal choice for DIY builders, flight controller installations, and anyone seeking to maximise performance in a minimal package. Whether you're building a custom RC drone, quadcopter, or other precision RC model, this receiver delivers the functionality and reliability that serious hobbyists demand.
The SPM4650 represents a significant upgrade over its predecessor, the SPM4648, by introducing enhanced functionality, fly-by telemetry capabilities, and a reduced footprint that makes it perfect for space-constrained applications. The receiver's small, lightweight design doesn't compromise on features or performance—instead, it opens up possibilities for builders who need a receiver that can fit into tight airframes or weight-critical applications. If you're serious about RC and demand professional-grade equipment for your builds, the SPM4650 SRXL2 receiver is exactly what you need.
Key Features
- SRXL2 Technology — The SPM4650 utilises Spektrum's advanced SRXL2 communication protocol, which is faster, more data-rich, and more secure than previous generations. This means you get blazing-fast serial data connectivity with support for up to 20 channels, enabling seamless bi-directional communication between your receiver and flight controller over a single signal wire, making it ideal for modern RC applications in the UK and beyond.
- Fly-By Telemetry Support — With integrated telemetry functionality, this receiver allows real-time feedback from your RC model back to your transmitter, giving you comprehensive data about your aircraft's performance, battery voltage, signal strength, and other critical parameters whilst you fly. This bidirectional communication enhances your flying experience and provides vital information for safer, more informed flying sessions.
- Dual Diversity Antennas — The receiver features two U.FL antennas that provide receiver diversity, which is essential for maintaining solid signal strength and reliability during flight. The extended coax antennas are specifically designed to deliver maximum signal strength in all orientations, which is particularly valuable when carbon fibre, metal components, or battery packs would otherwise shield the antenna in your installation.
- Small and Lightweight Design — Measuring significantly smaller than traditional receivers, the SPM4650 is purpose-built for DIY enthusiasts and builders who need to minimise weight and space constraints. This makes it perfect for everything from small FPV drones to lightweight RC aircraft where every gram matters and compact electronics are non-negotiable.
- Bind Button Installed — The receiver comes with a simple bind button pre-installed, eliminating the need to carry a separate bind plug or receiver to pair your system with your transmitter. This convenience feature means faster, easier setup at the field and less equipment to keep track of during your RC activities.
- Wide Voltage Input Range — The receiver accommodates a wide voltage input specification, making it compatible with various battery configurations commonly used in RC applications across the UK, from small-capacity packs to larger multi-cell configurations. This flexibility ensures the SPM4650 fits seamlessly into diverse RC setups and power systems.
- DSMX 2.4GHz RF Protocol — Spektrum's proven DSMX protocol provides remarkable range and interference-free performance on the 2.4GHz frequency, ensuring your RC model maintains a solid connection with your transmitter in crowded environments where frequency congestion is common. The 2.4GHz band has become the gold standard for RC control systems, and this receiver delivers all the reliability you expect.
- Serial Micro Receiver Format — As a serial receiver, the SPM4650 communicates with compatible flight controllers and devices through a streamlined serial connection, reducing wiring complexity and weight compared to traditional parallel receivers. This is especially valuable for modern flight controller designs that support SRXL2 serial communication.
Technical Performance
The SPM4650 DSMX SRXL2 Serial Micro Receiver represents the pinnacle of compact receiver design for modern RC applications. Its construction emphasises reliability and performance whilst maintaining an exceptionally small physical footprint—crucial for builders working with space-limited airframes, drones, and custom RC projects. The receiver utilises Spektrum's time-tested DSMX 2.4GHz technology combined with the powerful SRXL2 protocol to deliver up to 20 channels of control data with blazing-fast update rates and minimal latency. The dual antenna system with diversity reception ensures signal integrity in challenging electromagnetic environments, particularly important when carbon fibre fuselages, aluminium components, and high-density battery installations create potential signal dead zones. The bidirectional telemetry capability means data flows both ways between your RC model and transmitter—you send commands whilst receiving critical system information in real-time. With a simple bind button integrated directly onto the receiver and pre-installed connector options, the SPM4650 prioritises ease of use without sacrificing the advanced features that serious RC enthusiasts in the UK demand. The wide voltage input range accommodates the battery systems commonly used in UK RC applications, from compact single-cell packs to larger multi-cell battery configurations, making this receiver genuinely versatile across different build scenarios.
What's in the Box
- SPM4650 Receiver with pre-installed 4-pin connector
- Two U.FL Antennas for diversity reception
- 6-inch Receiver Extension Cable for flexible installation
- Product Manual with setup and configuration instructions
- Clear Heat Shrink Wrap for protection and waterproofing
What You Need to Complete
- Compatible Spektrum DSMX transmitter (2.4GHz)
- Flight controller or receiver module supporting SRXL2 protocol
- Appropriate power source matching your RC model's voltage requirements
- U.FL to SMA antenna adapters if your installation uses different connector types
Frequently Asked Questions
- Is the SPM4650 SRXL2 receiver suitable for beginners to RC? — Yes, the SPM4650 is appropriate for builders with intermediate experience who are comfortable working with serial receivers and SRXL2-capable flight controllers. The simple bind button and straightforward installation make it user-friendly, though you'll need a compatible transmitter and flight controller to use it effectively. Beginners completely new to RC might benefit from starting with a more traditional parallel receiver setup before progressing to serial receivers like this one.
- What is the difference between the SPM4650 and the earlier SPM4648 receiver? — The SPM4650 improves upon its predecessor by adding integrated fly-by telemetry functionality, reducing overall size and weight, improving reliability, and enhancing the feature set. Both receivers use DSMX technology, but the SPM4650's SRXL2 protocol is faster and more capable than earlier serial standards, providing significantly better bidirectional communication with modern flight controllers.
- Can I use the SPM4650 with different transmitter brands? — No, the SPM4650 is specifically designed for Spektrum DSMX 2.4GHz transmitters. It will only bind to and work with compatible Spektrum transmitters—it is not compatible with Futaba, Sanwa, JR, or other RC radio system brands. You must use an authorised Spektrum DSMX transmitter to operate this receiver.
- How many channels does this receiver support? — The SPM4650 supports up to 20 channels of control data through the SRXL2 protocol, providing exceptional flexibility for complex RC models with multiple servos and control surfaces. This channel capacity far exceeds what most small RC applications require, making it future-proof for ambitious builds.
- What voltage range does this receiver accept? — The SPM4650 features a wide voltage input range designed to accommodate the variety of battery configurations used in UK RC builds. Consult your specific flight controller's documentation to confirm the exact voltage limits, as the receiver itself is designed to be compatible with standard RC power systems.
- Is this receiver suitable for FPV racing drones? — The SPM4650's small size, light weight, and SRXL2 telemetry make it suitable for FPV applications where these characteristics matter. However, you'll need a flight controller that supports SRXL2 serial communication. It's worth confirming your specific drone's flight controller compatibility before purchasing.
- How do I bind the receiver to my transmitter? — The SPM4650 includes a simple bind button for easy pairing. Press the bind button on the receiver, enter bind mode on your Spektrum DSMX transmitter, and the two will automatically pair. No separate bind plug or receiver is required—everything you need is included in the box.
- What does the included 6-inch extension cable do? — The receiver extension cable allows you to position the receiver away from your flight controller, which can be useful for optimising antenna placement and signal reception. This flexibility helps you mount the antennas in better positions for consistent signal strength throughout your RC model.
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 Receiver w/Connector Installed P-SPM4650C 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.
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