Review: Frsky R-XSR Receiver – The new “Best” mini quad RX?

The Frsky R-XSR receiver is the smallest RX that can do 16 channel SBUS and SmartPort telemetry. It’s the go-to option now and replaces the XSR or X4R-SB for Frsky TX users who own a Frsky transmitters such as the X9D and QX7.

You can purchase the Frsky R-XSR radio receiver from

Why you want to buy the R-XSR?

When you ask an experienced mini quad pilot using Frsky TX, “What’s the best Frsky receiver?” The answer is probably going to be “XSR” or “X4R-SB”. But the new R-XSR might be the new answer to that question.

Nowadays, the following features have become the standard for Frsky mini quad receivers:

  • SBUS
  • SmartPort telemetry
  • Diversity Antennas (full range)
  • Small and light weight

And the R-XSR ticks all the boxes yet it’s tiny compared to the XSR and X4R. It’s basically just the XSR but in a much smaller form factor.

It comes with IPEX antenna connectors so you if damage the antenna you can easily buy a new one and replace it.

Here is a comparison table between these RX’s.

Product Page R-XSR XSR X4R-SB XM+
Price (Oct 2017) $25 $17 $29 $13
Size (mm) 16 x 11 x 5.4 26 x 19.2 x 5 40 x 22.5 x 6 21.5 x 12 x 3.5
Weight 1.5g 3.8g 5.8g 1.6g
Voltage 4V-10V 4V-10V 4V-10V 3.7V-10V
Current [email protected] [email protected] [email protected] [email protected]
SBUS ? Yes Yes Yes Yes
S.Port ? Yes Yes Yes No

It might even replace tiny receivers like the XM+ RX which were only released earlier this year.

Check out this post to find out aobut other Frsky RX for mini quads.

New Feature – Receiver Redundancy

When I read through the manual of the R-XSR RX, I found it has a new and interesting feature called “Receiver Redundancy”. If you look at the pin-out of the R-XSR, you might realize there are the SBUS_IN and SBUS_OUT ports.

What it does, is allowing you to connect a separate SBUS receiver to the “SBUS_IN” of the R-XSR. When the R-XSR fails and loses signal, the other receiver will try to take over.

But not both receivers are connected to the same Taranis internal TX module, you will also need a separate TX module such as the XJT module plugged in to the TX module bay on the back of your Taranis.

So there would be two separate connections. You can even use a separate Taranis TX rather than an XJT module if you want.

For example you could use the XM+ and connect it up to your R-XSR like this:

In my opinion this is quite a cool idea that could save your quad from hardware failure and bad signals, but I don’t see it being used by ordinary pilots and racers due to the complexity of the setup and the cost for additional equipment.

Why you might not want to buy the R-XSR, yet?

However, the new R-XSR is not perfect and you might not want it get it, just yet.

As we speak, LUA script is still not compatible yet (which allows you to change PID, rates, VTX settings etc from your Taranis). As far as we know this should be fixed soon with a firmware update. Update (Oct 9th, 2017): Frsky has just fixed the issue with LUA script, make sure you update your R-XSR with this latest firmware. Here is the instruction how to flash Frsky receiver firmware.

The second issue is finding the uninverted Smart Port signal. It is possible to get the uninverted S.Port signal on the board just like other receivers as shown in this tutorial, but the pin is so tiny it’s quite challenging to solder on.

Finally, the antennas are not optimal. I wish they just follow the XSR and solder the antennas directly to the receiver rather than using those fragile iPEX connectors which are only designed for a few mating cycles.

And just like the XSR, the R-XSR is using “1/5 wavelength” antennas, which means the antenna elements shorter than the original X4R-SB of 1/4 wavelength antennas. Many people including have reported range issues and complained about it to Frsky. We’ve been told the reason behind this design is to reduce the chance of a prop strike, which doesn’t make much sense to be honest. However if you are having range issue, you can simply strip the antenna shielding to extend the antenna element and experiment until you find your desirable length.

If none of these issues bother you, then you should definitely get it while they are still in stock. But because of the release of the new RX, the old XSR prices have dropped considerably to only about $17.

Manual

Update (Oct 2017)

Frsky finally listened and might release a version of the R-XSR RX in the near future that has a separate, uninverted SmartPort output. This is great news for those who are running an F4 board that doesn’t have an inverted UART for S.Port signal. We don’t know when this will be available yet.

Update (13 Oct 2017)

Frsky has just released a new revision of the R-XSR, that has added the “uninverted SBUS” and “uninverted Smart Port” solder pads. As far as I know, they won’t release a version with just the uninverted signals, so this is it. But still it’s much easier to solder to.

Here is an image provided by Frsky – the “B” pad is uninverted SBUS, “P” pad is uninverted Smart Port.

Antenna Replacement

The R-XSR uses smaller IPEX connector for the antennas than the original X4R-SB receiver, they are called “IPEX 4th Generation”. Be careful when shopping around for antenna replacement.

I found this on Amazon (US), only $12 for 20! http://amzn.to/2EVI6c0

For international buyers, this is the only source I can find so far: http://bit.ly/2H42gRy

35 thoughts on “Review: Frsky R-XSR Receiver – The new “Best” mini quad RX?

  1. fernando

    hi oscar. i have proble with this and jumper t8sg. i put in “frsky” and “frskyX” with 8 channel bur dont bind. what happen? maybe power? thanks

    Reply
  2. Adriano Pangelinan

    Oscar with all the new OSD functions in BF, is there any need to have smartport telepathy? I’m considering the XM+ because I currently think RSSI is all I need since I have an excellent F4 FC and I’ll rely on BF OSD for PIDs, telemetry etc. My perspective is someone who has only used the Turnigy Evolution but recently decided to get the FRSKY QX7 (for better range and more options), so I don’t understand all the features I haven’t used yet. :)

    Reply
    1. Oscar Post author

      For me there are 2 reasons why use Telemetry
      – OSD is useful, but it relies on video, telemetry is independent of video signal
      – You can change PID/Rate/BF settings using LUA script and SmartPort

      Reply
      1. Shaun

        – Telemetry works better for flying line of sight as you don’t have the video feed in that situation

  3. Frank S McNew

    How can I find the date of the article I am reading?
    I must be blind but if you would tell me where to look it would help me to know how recent the information is?
    Thank you,
    Frank

    Reply
    1. Oscar Post author

      just below “related posts” and above the comments. For update and changes I keep a log of history at the end of the post too :)

      Reply
      1. SadLeprechaun

        Yes but what if you have no Taranis? I use a XJT module with a TBS Tango radio. I want to get this but no RSSI pad, I am uncertain how it would work. I use SBus and BF 3.2.4

  4. Sander

    I have problems with my r-xsr frsky receiver range, I’ve already downloaded the latest software but nothing helps. I can go about 200 meters far and then I have no more reach. what can I do? I can use the antenna of an x4r sbus receiver instead of the original r-xsr antenna

    Reply
    1. Oscar Post author

      It could be an issue with the antenna, as pointed out in the review.
      Strip the shielding back and let the exposed part be 31mm and see if you get any improvement.

      Reply
      1. Oscar Post author

        it is full range, i have been flying up to 800m without any problem (I haven’t tried flying further yet, my park is not big enough :) )

      2. Oscar Post author

        I doubt that will improve range.
        In theory the XM+ should have similar range to the R-XSR. Make sure your antennas are placed 90degree apart and not blocked by the frame.

    2. Kevin

      I can confirm that this is a problem with two copters i own that both use the R-XSR constant tripping the RSSI alarms. Thus far I have swapped out the antennas for new with no noticeable improvement. However previously the XM+ had a significantly longer range and rarely tripped the RSSI alarm.

      Reply
  5. VT

    Hi Oscar, was appreciate if you can give answer as is this R-XSR receiver was able to power direct from fully charged 2s lipo(8.4Volt) ?

    Reply
  6. Rookie

    new batch useless for me, because i cant solder anything to those “uninverted pads”. no idea whats up there, but no solder sticks on that tiny pad (and no, i am not a soldering beginner).

    Reply
    1. Oscar Post author

      there could be a thin layer of coating, you can scrap it off gently with a cutting knife. and please use flux to help solder sticking to the pad.

      Reply
    2. Kev8

      well obviously you are a beginner, there is no issue soldering to these little pads. Use your brain just alittle people make sure there is no coating on it which there is then hit it with a small tap of flux and touch it for I dont know what 1 millionth of a second and its soldered. I mean come on guys what are all these questions beginner people asking these or what. Like can you power with 2s lipo 8.4v I dont know what do you think it rated for 4-10v I mean you tell me what does that mean to you dude to the guy asking the question. That would be a yes RIGHTTTTTTTTTTTT well then yes. I mean hell can I power this using 5v can I power using 10v hey OSCAR can I mount this in a drone. IDK hey oscar I cant solder, hey oscar why did you make this product hey oscar its your fault hey oscar I think this other product is better hey oscar did you know telementrty works better for LOS no no im sure you didnt know that did you, I mean I guess that guy totally did not get what you meant, when he said that, as in yes you have video data in the OSD but its video, Use sport telm is great back up and good way to double check if your OSD is correct because its different systems. I mean whats up with these people in the comment section man. I can see you biting your tounge on these answeres and questions, where your just like really. keep up the good work there oscar now why did you make this receiver again or atleast thats what some of thesepeopel act like.

      Reply
      1. Snarl

        Enter the angry drunk troll who writes like a 3rd grader.
        I guess Kevin was Never a Beginner. He must’ve been born with All the Knowledge of the Universe baked into that angry pea brain of his
        I wish I was Kevin, then I would know EVERYTHING!!!!!! Except I wouldn’t be able to write very well

  7. Jonathan Dahood

    I have the r-xsr , and almost chopped a antenna last night.
    So what antenna should I buy? Im looking on alofthobbies , and don’t see ones this size.
    Thank you!

    Reply
    1. Oscar Post author

      search for “IPEX connector antenna for Frsky”.
      They actually use the same antenna as the XM and XM+, so it should be pretty easy to find.

      Reply
  8. Mark8

    Just recived a R-XSR v2.3.1
    0Ohm betwen the Pad of the inverter who you can find on the web and the P pad.
    Orderd on Bangood

    Reply
  9. Macflyer9

    Oscar, thanks for the update on the R-XSR. Can you post up a picture of the R XSR with the applicable item circled for soldering? I picked up several R XSR’s and suspect it will be a while before FrSky will release the un-inverted one. Cheers, and thank you.

    Reply
    1. Oscar Post author

      I bought the R-XSR two weeks ago and they turned out to be the latest batch with uninverted pads on them. So yours might be the latest ones too.

      Reply
      1. Justin Mitchell

        Oscar, where’d you pick them up? I’m going to order one, and want to make sure I get the latest batch..

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