Mini Quad Long Range RC Options: TBS Crossfire & FrSky R9M

For long range flying, RC links is just as important as your FPV video link. In this review we will have a look at some long range RC options: the Frsky R9M and TBS Crossfire. These are the two most popular TX modules compatible with the Taranis X9D and QX7 transmitters.

Check out this article to learn about the basics of a radio transmitters and receivers.

You can get FrSky R9M bundle with R9 Receiver

You can get TBS Crossfire modules from:

TL;DR – R9M or Crossfire?

Frsky’s R9M system is much cheaper than the Crossfire, but the Crossfire has better features. In the end of the day, it comes down to which company you want to support and what you can afford.

R9M R9M Lite Crossfire TX Crossfire Micro TX
Price $60 $45 $208 $100
Frequency 915MHz (non-EU)
868MHz (EU)
915MHz (US, Asia, AU)
868MHz (EU)
Smallest RX R9 Mini RX ($13) Crossfire Nano RX ($40)
Output Power 10mW
100mW
500mW
1W
100mW 100mW-2W 25mW
100mW
250mW

If you plan to fly long range, it doesn’t matter which system you choose, the limiting factor is still the video link. In theory it will even out-perform 1.2GHz video link.

Yes, Crossfire is slightly faster than SBUS, but not everyone can notice the milli-second level difference, especially when you are flying long range.

Why 900MHz for Long Range?

2.4GHz is the most common frequency used by radio transmitters, by using the built-in TX module, you can probably get a few hundreds meters of range from a Flysky TX, 1 miles from a Frsky Taranis at best.

The reason that the Frsky R9M and TBS Crossfire can do multiple miles is because they are broadcasting at much lower frequency, i.e. around 900MHz.

As explained in our TX buyer’s guide, lower frequency is better at penetrating obstacles, however the downside is the relatively large antennas.

Luckily the antennas in these two modules we are reviewing are compact enough for easy transportation and installation in mini quads or wings.

Be aware that 900MHz is not legal for hobbyists to use in every country, because that’s the frequency our mobile phones operate at as well. For that reason we can only use 868Mhz in Europe, and 915Mhz anywhere else. Make sure you check your local regulation before broadcasting.

I have some tips about long range flying you might find interesting.

FrSky R9M module and R9 receiver

FrSky’s previously released a long range receiver L9R for the Taranis’s 2.4GHz system. The new R9M TX module and R9 receiver is for the 868/915Mhz frequency.

R9M has the same size and look of the 2.4Ghz XJT module.

What’s in the box?:

  • R9M Module
  • RP-SMA Dipole Antenna
  • Instruction Manual
  • R9 Receiver with “T” Antennas

R9M TX Module

R9M Module has switches for choosing the transmitting power, Smart Port, RS232 Serial Port Function Button and LED light indicator.

Operating frequency (868Mhz vs. 915Mhz) can be selected by flashing the module with dedicated firmware.

NOTE: We have been supplied with an earlier version of the R9M without the XT30 socket.

R9M Features:

  • 2 power settings in EU Version Telemetry: 25mW (with telemetry) and 500mW (without telemetry)
  • 4 power settings in Non-EU Version: 10mW, 100mW, 500mW, 1000mW (all with telemetry)
  • Micro USB port for firmware updates

R9 Receiver

R9 RX Spec:

  • Dimension: 43mm x 27mm x 14mm
  • Weight: 16g
  • Power Input: 3.5V-10V
  • Range: 10km+
  • EU Version: 8 Channels with telemetry and 16 Channels without telemetry
  • Non-EU Version: 16 Channels with telemetry
  • Supports redundancy function
  • MMCX antenna connector

The R9 receiver has similar size to the X8R, and it’s enclosed in a plastic case. Taking apart the RX, we can see there are two PCB’s stacked together.

Dedicated RSSI pad is highlighted below.

 

R9 comes with “T” style antennas. Instead of tube or wires it has plates with the antenna active elements imprinted on them. It was quad and to capture those tiny tracks on the plates though. Plates itself are very thin and flexible.

Correct antenna placement for the R9 is on the photo below. Both plates need to be 90 degrees to each other.

The R9 is currently the only receiver that works with the R9M module, but we have heard news about the “R9 Slim” to be released soon, which is basically a smaller and lighter version of the R9 for smaller copters.

Update (Apr 2018): Frsky released a smaller receiver – The R9 Slim RX.


Crossfire TX, Micro TX and Micro V2 Receiver

Learn how to use the Crossfire with Betaflight.

Crossfire is developed by TeamBlackSheep (TBS) and has been on the market for years now. They offer two TX modules:

  • Crossfire (often called “Crossfire Full”)
  • Crossfire Micro

Incompatibility With Frsky Taranis Q X7 & Q X7S

There is a bug when using the Crossfire with Taranis Q X7 or Q X7S, where the Taranis would constantly shout out warnings “Telemetry Lost”.

This is caused by changes FrSky made to the hardware in the latest QX7 and QX7S, which results in Crossfire modules can’t operate at full baud rate in these radios.

There is a DIY hardware mod required to fix this issue if you plan to use the Crossfire with the Taranis QX7, which involves installing a small chip inside of your radio (the chip comes with your Crossfire).

However this issue does not affect the Taranis X9D-Plus and some very early batches of QX7, and they are fully compatible with the Crossfire out of the box.

Crossfire “Full” Transmitter Module

Features:

  • 5 power settings – 10mw, 25mW, 100mw, 500mw, 1000mw, 2000mw
  • CRSF protocol, lower latency than Frsky’s protocol (more info)
  • 8 / 12 channel output via PPM/SBUS/CRSF
  • Transmitter LED shows link health
  • Built in OLED display for easy configuration
  • You can update receivers wirelessly
  • Micro USB port for firmware updates
  • Comes with SMA dipole antenna
  • Bluetooth module
  • Spectrum analyzer
  • Operating frequency (868Mhz & 915Mhz) can be selected from the OLED screen menu

The Crossfire “Full” module requires some assembling before you can attach it to the radio.

It comes with a JR bay adapter that has sticky foam on the back. There are 4 pins in the adapter that have to be aligned with the holes in the module itself. Two wires coming from the adapter are going to RC Input and Exp.Port. They are of a different sizes so it’s easy to figure out what plug goes where. Once connected the Crossfire is ready to use.

The Crossfire module requires external power source when using 1W and 2W mode via the XT30 connector.

OLED display can be use for configuration of the module and receivers but also it has a few useful functions like spectrum analyser and find mode which helps to located lost aircraft. If the quad has a TBS GPS attached (via FPV vision or TBS Powercube) it can even show the GPS coordinates. This module is just packed with useful features!

The GPS coordinates are useful for finding lost models, and I tested it and the accuracy was within 5-10 meters.

Crossfire Micro Transmitter Module

The Crossfire Micro TX module is a smaller / lower power version of the Crossfire “Full” module. It can fit inside the Taranis external module bay without any adapter.

Features:

  • 868Mhz (EU/Russia), 915Mhz International frequency
  • Dimensions 66 x 48 x 21 mm. 47g of weight
  • Built in Telemetry
  • 2 power settings – 25mW
  • and 100mw
  • CRSF protocol
  • Low latency, 150Hz update rate
  • 8 / 12 channel output via PPM/SBUS/CRSF
  • Transmitter LED shows link health
  • Receiver “over the air” update
  • Micro USB for firmware updates
  • SMA dipole antenna
  • Configuration of the module and RX can be set using Taranis LUA script, including changing operating frequency of 868MHz and 915MHz

The Crossfire Micro has no OLED display and all the configuration can only be done via LUA script.

Before binding a receiver, you can put the TX module in bind mode by pressing the button in the middle of the module.

There are only two power settings available: 25mW and 100mw, there is no external power source needed for such low output power.

Crossfire Micro V2 Receiver

Features:

  • Dimensions: 40mm x 15mm x 10mm.
  • Weight: 3g
  • BST port expandability
  • Receiver firmware can be updated wirelessly from the TX module
  • Comes with two U.FL antennas (one spare)
  • Comes with BST wires, standard connector wire and servo adapter

The white wire is the Active part of the antenna while the black wire is the ground plane.

The best way to install the antenna is to keep both wires opposite to each other (180 degrees) and perpendicular to the shielded antenna wire (90 degree), like a “T” shape.

Best to keep the antenna vertically but horizontal placement (makes more sense on a mini quad) is also fine but not for crazy long distances.

TBS also offer a ready made antenna called the “Immortal”. It has better protection against crashes and it’s easier to mount in a mini quad.

Crossfire Full vs Micro – Which version to choose?

The Crossfire Full version is over twice as expensive as the Micro ($209 vs $99), is it twice as better? Let’s take a closer look at the differences between the two TX modules.

The Crossfire Full has the following features that the Micro doesn’t:

  • OLED Screen for configuration
  • Bluetooth module (for telemetry distribution to tablet or a laptop)
  • Output Power up to 2000mW (2W) vs the 100mW of the Micro

Both modules supports LUA script so changing configurations are equally easily.

For FPV mini quad racers, the Micro TX should fulfill most of the requirements. It’s been reported that the Crossfire Micro RC link has 10Km range or even further depends on the condition. Can your mini quad travel 20Km with a 1300mAh battery pack? Probably not :) So that range is more than enough.

If I was getting the Crossfire Full version, it would because of the OLED screen and the features that come with it. The extra range that it offers would probably be a bonus too.

The built-in Bluetooth module is the least important consideration in my opinion.

The Pro’s and Con’s of Frsky R9M and TBS Crossfire

Let’s compare the two long range RC systems in terms of user experience and features.

What I liked about the FrSky R9M and R9 combo?

  • Compact TX module
  • It’s a FrSky product, so it’s fully compatible with the Taranis radios
  • Removable antennas with MMCX connectors on the R9 receiver. Making it easy to replace without worrying of damaging the socket
  • Very good price at $99 for both TX module and RX

What I don’t like about the FrSky R9M and R9 combo?

  • Switching power settings can only be changed using dip switches, you cannot change settings using Taranis LUA script
  • Only one compatible receiver available (at the time of writing this article)
  • R9 receiver is a bit large for mini quads (but it’s fine for wings and airplanes)
  • R9 receiver antennas have an unique shape that is tricky to mount on a small aircraft
  • Fewer power options than on Crossfire
  • The R9M unit we received was sitting a bit loose in the JR module bay
  • Instruction manuals could be better

What I liked about the TBS Crossfire system?

  • Flexible options, users can choose between Full & Micro version depending on budget, range requirement and features
  • Good selection of transmitting powers (makes it flexible since the regulations are different in every country)
  • Lost-Model-Search mode and last GPS coordinates can be shown on the Crossfire “full” module OLED display
  • Configuration can be changed via OLED display (on the “Full” version) and LUA script (on the Micro version)
  • Compact and light weight receiver
  • Informative & well written instruction manuals

What I don’t like about the TBS Crossfire system?

  • The Crossfire “Full” module is more expensive ($209), Micro is the same price
  • DIY Mod is needed to use with Taranis Q7X, good soldering skills are essential
  • The LUA script feature is still buggy, it does not always work with the Micro module, sometimes it doesn’t even connect at all
  • The U.FL connector on Micro V2 RX is fragile and prone to damage
  • The Crossfire “full” version is a bit bulky and sticks out a bit from the back of the radio. It’s more likely to get damaged if not protected properly

Happy flying !

Picture Credit: Artur Banach

21 thoughts on “Mini Quad Long Range RC Options: TBS Crossfire & FrSky R9M

  1. Richard Raueiser

    Hello,
    Could you find out what brand of connectors are on the Crossfire tx?
    “Two wires coming from the adapter are going to RC Input and Exp.Port.”
    Thank’s

    Reply
  2. Mark

    I have the first version of the R9m without the xt30 is it ok to run at 1w off the Taranis without external power? Do you know if I can add a external power source somehow?

    Reply
  3. Pascal

    I bought the R9M & R9 system is Sep. but I have not used it since I can’t get a proper failsafe working with OpenTX. I mean that the only possible failesafe is “hold” and not programmed channel positions. Apparently, it works with FrSkyOS though.

    Anybody confirming this?

    Reply
  4. Esher

    I bought R9/R9M combo at the very first batch, then placed it on the shelf, because it was 900Mhz and guys from Frsky told me that there will be no EU (868Mhz) update.

    Then i read your “Operating frequency (868Mhz vs. 915Mhz) can be selected by flashing the module with dedicated firmware.”
    What!? Is that true? What firmware should i download to make my modules operating at 868Mhz ?

    Reply
    1. Artur Banach

      There is EU firnware on the product page. Update was dated 31/10/17 as far as I remember. I have done that update. It works

      Reply
  5. Bitheldude

    Thanks for the helpful and informative review on these mid and long range solutions. However, I would request you add information about how this would work with Spektrum transmitters, too. (such as the DX6i). Is this compatible? Does it just use the trainer port on the back of the transmitter?

    Thanks!

    Reply
    1. Thomas

      Yes, you can use the trainer port on your DX6i to connect but I’d recommend against it. Reason, the little plug can move and intermittently disconnect your LRS system, powering it off, then on, causing you to FS and crash. If youre serious about LR, get a Taranis, they’re inexpesive and considered the standard for all things FPV. The connection to a Taranis is via pins on the back of the TX, you simply plug the CRSFR or FRSKY LRS module in and you’re done. The Taranis is also infinitely easier to program than nearly any TX on the market.

      Reply
    2. Goof

      Spektrum? Lol.

      This isn’t a Nitro Racer. These are Quads. Anyone using anything but FrSky or Futaba for a Quad is an idiot.

      So why cater to idiots?

      Reply
      1. Paul Morris

        I consider my self far from being an idiot and I don’t use either of the brands you have declared the essential choice. There are a number of well known pilots using spectrum e.g. Skitzo and le drib to name a couple. A recent rotor riot video showed brands like radio link are also equal in range to the brands you mention. Get wise, open your eyes, put your brain in gear!

      2. John Hendry

        You need to measure the latency before saying Spektrum is for idiots… and talk to long range pilots about RF issues as well. Fact is Spektrum has better quality control, RF and latency specs, and to have CRSF on DX9 it only takes adding a servo connector so add costumer support as well…. whereas FrSky damaged radio performance in new radios so XFire can’t be used except with PPM and that a low blow IMO.

  6. Mark Matthews

    Great informative article.

    The only thing I would like to mention is that a stock Taranis with an L9R receiver will happily do 3 miles+ which is a smidgen better than the 1 mile you say at the beginning.

    Reply
    1. Artur Banach

      True. But it’s still 2.4Ghz and as far as I know doesn’t carry any telemetry. We have been talking here about 900MHz ones.

      Reply
    1. Fly High

      re: options for RX/TX – when using long range link – get a powerful transmitter- and good antennae’s – with a high dbi rating. you can now pick up a 1000mw for under 50 dollars. (I think aomway has one and there are others) the aomway shows a range of at least 22km – (I’ve heard of one transmitter over 100km – ) so with a 1w transmitter you shouldn’t have any issues at least with range. you might want to check the reg’s in your area for power output to ensure you’re flying legally.

      Reply
  7. Darren

    Hey Oscar,
    Thanks for your review on these new long range options. I was wondering off the topic of your review, which fpv goggles that you personally like the best/ use daily. My Skyzones just died and there are so many out to choose from.
    Thanks!

    Reply
    1. Oscar Post author

      I personally use the Fatshark Dominator V2, have had it for a long time now, very happy with it.
      It’s discontinued, but the Attitude V3 has similar spec to the Dom V2, best budget option for 4:3 cameras.
      The Dom V3 is 16:9 but also very nice goggle if you use 16:9 cameras.
      If you’ve got budget the Dom HDV3 is the best for 4:3 cameras.

      Reply

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