Spektrum SRXL2 DSMX Serial Micro Receiver, SPM4650

Coming from fixed-wing aircraft, I've owned a DX9 for quite some time and I wasn't yet ready to jump on the FrSky/Taranis bandwagon just to fly drones. My first quad was a Blade Torrent (great for learning). My recent second, a Diatone GT R349 (great for ripping). I installed this receiver onto the R349 and it is absolutely fantastic (great range, no noise). I do not recommend this to those who are not technically inclined; nor to those who aren't familiar with fine soldering work. It requires flashing a forked version of Betaflight (v4.0.3 as of this writing) onto the flight controller and soldering the output wires to the flight controller's 5V, GND, and (signal to) TX UART connection. You will be setting up Betaflight from scratch (or importing from a stock 4.0 setup and then tuning). Intimidated yet? Search the RCGroups threads for SPM4650 and get educated. It's worth it though -- if you own any Spektrum Gen 2 radio (and flash it with the latest firmware), you'll get the ability to change your Betaflight settings right in the pit via the radio's telemetry screens (thank you Spektrum devs!) -- an alternative from setting things via OSD (of course, your drone hardware needs to support Smart Audio/IRC Tramp). To sum up, it's a small, powerful, feature-rich, telemetry receiver we few die-hard Spektrum fans (the few, the proud) can now utilize for our micro builds. Better late than never!

First off if you fly fixed wing aircraft these receiver may not be what you're looking for. If on the other hand you are looking to build a multi-rotor of almost any size from whoop size all the way up to beast this receiver fills that void. the SPM4650 isn't just a smaller spm4649/8. It has gone one or maybe two levels beyond. The stand out features to me are weight and features. This is the smallest full range high speed receiver that Spektrum users not wanting to invest in Crossfire a good place to be. I've had several flights using this so far on a 5in freestyle quad and subjectively this feels to me to be the most responsive quad I've ever flown that didn't run crossfire. Great job please keep supporting this product.

As several reviews have pointed out, you may need to upgrade your flight controller's firmware before you can use it. So buyers should verify their flight controllers can support the versions of betaflight they need before buying it. Betaflight did not add support for SRXL2 in official releases until v4.1 and I believe support was not incorporated into the configurator until even later (which meant you had use the command line interface to enable the options). Betaflight v4.2 and Betaflight Configurator 10.7.0 appear to fully support this receiver without problems. So far this receiver has worked well for me. I have it attached to a Diatone Mamba F405 flight controller that currently uses Betaflight 4.2. The range and signal strength seem to be good, although I will admit that I haven't really tested the range very much as I have been flying fairly close range (a couple hundred yards at most) in open areas. This receiver allows the flight controller to get useful information like RSSI data and allows my FC to send telemetry data back to my radio (which is nice if I want to set my radio up for things like voltage alarms). I have 4 minor things that kept me from giving this a 5/5 star rating. 1) The included wires use cheap, stiff, plastic coating instead of silicone wire insulation. This is pretty minor, in my opinion, but it does make the wires feel cheap and they aren't as flexible as silicone wires, which can make wire management a bit more annoying in a small quad. 2) Spektrum lets you register their products with your account on their website for things like updates and warranties. But to register this receiver, you need the serial number. The only way to get that is to buy ANOTHER spektrum part that lets you connect the receiver to a computer to get the SN and update its firmware (assuming you soldered the plug to the receiver, and didn't just solder it directly to your flight controller). I am not buying that, so I can't register it. 3) Spektrum made some tutorial videos on Youtube when this was first released. That is a great idea and that video contain some useful information. However it also contains a lot of dated information that can mislead users. For example, when this product was released, official betaflight builds didn't support this receiver and spektrum, temporarily, had their own Betaflight builds. The video tells users to use those custom builds to update their flight controller. That would be a bad idea now since standard Betaflight builds fully support it. The videos should be updated to reflect current data and eliminate misinformation. 4) The price is a bit much for what it is. This is a good product, but there is room for improvement.

1.4 gram and 13.5mm. I installed it at the tail, inside the boom, wired with thin cables to the main receiver. Whole installation with wires, solder and connectors was ~ 4 grams. Great as backup receiver in lightweight carbon fiber setups.

This is the best spektrum rx for Mini quads. Make sure your flight controller supports betaflight 4.1 or higher or else it won't support the SRXL2 protocol. The receiver can run 3.3 to 8 volts, which is a huge upgrade from other spektrum receivers. No need for a bind plug or grounding anymore either because this component comes with a bind button. Spektrum DSMX protocol doesn't have the greatest range but this receiver has better range compared to my other rx.

I upgraded from a Happymodel Speki+ to this. The Happymodel was a pile of junk. Would not remember bind, antenna popped off in a small crash, no useful telemetry. This receiver is much higher quality right off the bat. The antennas and connections are more sturdy, even the bind button is more robust. It actually remembers my bind on power cycles, which made me so happy. Then I discovered how much telemetry is available! I can finally monitor my battery voltage! Plus way more than that. Only wish it was $10 cheaper.

This receiver works very well in my new 5 inch drone. No complaints on my end

I had a few issues getting everything to work, however it was not the recievers fault. Before going in and switching your reciever type, be sure your flight controller is fully updated. The reciever connected to transmitter effortlessly. This is a great product. Very pleased with it.

Développement Open source

Recommend seller

Bind facilement, très petit, fonction télémétrie se configure automatiquement, compatible avec betaflight 4.2.11.

Hat mit meiner DX6 super funktioniert

I think this is a great little Spektrum receiver, but currently I think it is not supported enough in the RC community. I have tried mine on a Flywoo 1s Firefly (PNP) version, and only ran into problems trying to connect and once connected things didn't work as they were suppose to, like having control of the throttle only until 1/4 throttle and after that I have nothing and motor run steady at about 1/3 throttle. The only way to cut the throttle is with a disarm switch. I tested the same quad using a Lemon satellite RX and had no issues at all. It fairly obvious to me Betaflight still has problems with the new Spektrum SRXK2 protocol. For now I would stay away from this type of RX unless you really know your stuff and in that case fill us in how to solve the problem.