RadioMaster TX16S Mk3 - review

Since its humble beginnings back in 2020, the TX16S has turned into a big success for RadioMaster. From the original Mk1, to the Mk2 with better gimbals and other improvements, the TX16S has evolved into a reliable and popular workhorse. My own Mk1, retrofitted with AG01 gimbals, has served me well in over 30 F3F competitions.

Times are a-changing, though. Whereas multi protocol modules (MPMs) were all the rage back then,  we now have a new kid on the block in the form of ExpressLRS. In addition, EdgeTX has made increasing demands on the processor. 

Enter the TX16S Mk3. It's not just a facelift, more a re-imagining! So, has RadioMaster created a worthy successor? Read on and find out...

TX16S Mk 1 (left) and new Mk3 

Full disclosure: RadioMaster provided me with a review unit to keep. However, they have not imposed any conditions or seen this review prior to publication. All views expressed are my own. Finally, there are no affiliate links in this review.

Overview of the TX16S Mk3

The RadioMaster TX16S Mk3 is a classically styled, modern mid-to-high end radio. It's offered in two versions. 

• Standard, with regular gimbals and a plain finish. 
• MAX, with CNC gimbals, anodised metalwork and a faux carbon finish. 

The unit for review is the MAX. I have to say, it does look rather nice!

Let's get one thing out of the way first: the TX16S Mk3 is an all new radio, not an incremental upgrade. That said, the influences are obvious: it gets its layout from the Mk1, its RF capability from the GX 12, and its H7 processor from the TX15.

The Mks3's RF module supports the latest Gemini and Xrossband modes, as well as regular ELRS. The 4-in-1 MPM is not an option any more (an external MPM module can be used, however).

RadioMaster TX16 Mk3 MAX

What's in the box

My Mk3 arrived safe and sound after its journey from China. 

Inside the package was a white display box, and inside that was RadioMaster’s signature semi-rigid transmitter case. The case incorporates a carry handle and a storage area for accessories.

Nestling inside the case was a rather nice looking transmitter.

Semi-rigid padded case

Also included in the package are:

• Alternative shoulder panels (without slots for sliders)
• Set of soft gimbal springs
• Allen key for adjusting spring tension
• Grub screws for stick ends
• Quick Start guide
• Stickers

Stickers, quick start guide and screen protector

Build quality

The build quality of the TX16S Mk3 is very good indeed. The shell feels solid in the hand, with no creaks when squeezed. The hinges (for top antenna and handle) feel robust, and are nice and tight.

The only slight nitpick is the battery hatch - it can be a little reluctant to slide in place until you get the knack.

Ergonomics

Ergonomics are a personal thing, nevertheless most would agree that RadioMaster did a good job with the Mk1 and Mk2. Let’s see if they've gone one better with the Mk3...

Comfort

The new shell is all curves and rounded edges. Compared with my Mk1, the grip it extends further down the back of the case for a more 'locked in' feel. And the top end of the grip has a recess for a spare finger. It all feels very nice in the hand.

Switches

The switch layout is essentially the same as previous versions, with only subtle changes. One nice thing is that the top switches (SE - SH) are easier to reach than previous versions.

Sliders 

The sliders have been moved from the side to the rear. This is a welcome change for thumbers like myself, however pinchers may find the new position difficult to reach. 

There is an issue though... the slider arms are very short and difficult to manipulate. 

Sliders are perfectly positioned for thumbers. Levers are too short.

Clearly I'm not the only one to have noticed this - a longer arm is already available courtesy @3djc. You can download the STL file from here.

Carry handle/antenna housing

At the back of the shell is the hinged carry handle. This also houses the second antenna. 

Carry handle doubles as antenna.

The handle doubles as a stand. When resting on a table with the stand extended, it's at the perfect angle for programming.

When retracted, the handle sits very low down the case. This means that the handle must be partially extended in order to hold the tx comfortably. Most pilots will simply keep the handle extended during each flying session. 

Carry handle/antenna folded down - sits over grip.

Weight

The weight of my unit is 965 g including batteries - that's 25 g heavier than my Mk1. The extra weight is small but noticeable. Balance with a neck strap is perfect when using 18650 batteries.

Switches and controls

Let's look in more detail at the twiddly bits:

Switches

No change from the previous versions. There are eight switches as follows: 

• Front: SA, SB, SC, SD are all 3-position
• Top front: SE and SG are 3-position
• Top rear: SF (left side) is 2-pos, SH (right side) is momentary

Pots

There are two pots designated S1 and S2 near the top of the unit. They're smooth acting with positive centre detents. These can be used as volume controls, gain adjusters etc.

Sliders

As mentioned earlier, the sliders LS and RS have been moved from the side to the rear of the shell. These controls are good for camber adjustment, motor control etc.

Auxiliary trims

There are two Aux trims designated T5 and T6. These are treated by EdgeTX as regular controls and can be used for a variety of purposes such as in-flight mix adjustment, camber trim etc. Like the regular trims, the Aux trims can store different values according to the flight mode.

Auxiliary trims T5, T6

Programming controls

The programming buttons have a nice positive feel and follow the usual RadioMaster convention. No change here. 

Function switches

Just above the screen is an array of six buttons SW1 - SW6. These look similar to those on the Mk1/Mk2, but have been moved to just above the screen... and they're now programmable. 

Programmable function switches

The buttons are configured in the Model Setup menu:

• A button can act as a momentary switch, or push-on/push-off switch.
• A button may be independent, or part of a group where activating a button deactivates the others.
• The startup state of a button can be configured 'On', 'Off' or 'As-last'.
• The RGB colours for the on/off states are configurable for each button. 

A button press can be simulated in EdgeTX using the new 'Push CS' special function.

Typical uses include: motor arming gestures, telemetry announcements, selecting rates etc.

AG02 gimbals

The Max features RadioMaster's latest AG02 CNC gimbals. Compared with the already excellent AG01 units, the new gimbals are said to have lower rotational inertia for better response to rapid inputs.

AG02 gimbals. Sweet!

There's virtually no jitter, and the ADC filter is disabled by default in EdgeTX to minimise latency.

Tension adjustment

The units came with hard springs installed, which suit me well. For those of a gentler disposition, RM also include a set of softer springs. Adjustments to tension and travel can be made from the front of the gimbal - no need to open the case.

Changing between mode 1 and mode 2

Changing between mode 1 and mode 2 can be done via holes in the case (after removing the grips).

Side cheeks removed, showing slots for mode changing.

End stop adjustment

The end points on each axis can be adjusted from the front - there's no need to open the case. Note that reducing the travel in this way will negatively impact resolution. If you want to reduce the travel in both axes, a better option is just to screw down the sticks. If you do adjust the end points, then do remember to recalibrate the gimbals.

All in all, the AG02 is an excellent gimbal.

Screen

One of the star features of the TX16S Mk3 is the 5-inch IPS screen. It looks huge! Resolution is 800 x 400 pixels. While I haven't tried it yet in bright sunlight, I'm confident that it'll be fine.

Mk1 (left) compared with Mk3

Ambient light sensor

Located between knobs S1 and S2 is an ambient light sensor for automatically adjusting relative screen brightness. The sensor can be activated using the 'Backlight' special function with the 'Ambient light' option. The idea is good, but it didn't work well on my unit  - hopefully this will be fixed in firmware.

Touch screen sensitivity

On the Mk1 and Mk2, the screen is recessed behind a bezel. On the Mk3, however, the screen is flush with the shell.

The new look is clean and modern. However, without the protection of the bezel, some care is needed to avoid brushing the screen and triggering a swipe action, especially when using the roller. 

For this reason, I will disable touch while flying. Touch can be enabled/disabled via a special function.

Removing the ETX graphic

For those who, like me, find the EdgeTX graphic distracting, there’s an easy way to hide it:

1. Open the System>File Manager menu
2. Navigate to the Themes/EdgeTX folder. 
3. Scroll down to the file background.png. 
4. Rename the file to, say, 'background_xxx.png'
5. Cycle the power 

Voilà - a nice clean background.

Sound

Sound on the review unit is excellent - at maximum volume the speaker is commendably loud with little distortion.

Tilt sensor

The TX16S Mk3 features a 2-axis tilt sensor. Tilt inputs appear as TltX and TltY. These supply a value proportional to the tilt angle. There's no built method of shake detection, so this will need some programming.

Batteries and charging

The TX16S Mk3 is supplied with a battery box for two 18650 LiIon cells (batteries are not provided). For those who need greater duration, there's lots of space for 21700 cells, or even a 6200 mAh LiPo pack.

18650 cells, with room for 21700s. Cells not supplied.

Charging is via the USB port at the top of the unit. The charger has an integral balancing circuit. According to the specs only LiIon cells with a nominal voltage of 3.7V should be used with the internal charger. 

Upgraded ELRS module

ExpressLRS (ELRS) is an open source protocol which offers much improved range and interference rejection compared with legacy protocols like ACCST.

The Mk3 features an upgraded ELRS module which supports the following transmission modes:

• Regular ELRS (single frequency, single or switched antennas)
• Gemini (single band/simultaneous dual frequency/dual antennas)
• Xrossband (simultaneous dual-band/dual antennas)

M2.4 GHz and sub-900 MHz are supported in all modes.

Gemini-X RF board

Maximum RF power is 1W, and there's both a heat sink and fan. That said, 100mW is more than sufficient for line of sight use (it's also the legal limit in the EU and UK), so the fan will never see action for most sailplane users.

Use with standard ELRS receivers

Most pilots will probably use single-frequency 2.4GHz mode, for use with receivers such as the RadioMaster ER6, ER6G, ER8G etc. This mode can be configured to use a single antenna, or switch between the two antennas. If using switched antenna mode, RadioMaster recommend that the top antenna be rotated 90 degrees.

Here's the recommended configuration for sailplane use:

• Packet rate: 100Hz or 333Hz
• Switch mode: 8CH/Full
• Antenna mode: ANT1 or ANT2 or 'switched' (do not use 'Gemini' mode!)
• Max power: 100mW
• Dynamic RF: On

Main antenna rotated 90 degrees

Gemini and Xrossband

Gemini and Xrossband are the newest flavours of ELRS.  With both these modes, each packet is transmitted simultaneously over parallel transmission paths.  

While Gemini is single-band/dual-frequency, Xrossband is dual-band. Both modes improve link quality in challenging RF conditions compared with regular ELRS. However they do not increase range. 

Each mode requires the use of the top antenna and the one in the handle. 

Antenna routing - LHS to top antenna, RHS to handle.

While these modes will be welcomed by drone pilots, I feel that they will be of limited interest to sailplane flyers, at least for now. Partly because 'ordinary' ELRS is 'good enough' for most applications... and partly due to the lack of compatible PWM receivers. Currently, the only Gemini PWM receiver is the BetaFPV SuperP, and this is a rather large 14-channel device.

ELRS Firmware and configuration

The RF module came with v3.6.3 FCC firmware. EU/UK users should note that LBT is not available at the time of writing as it's currently awaiting certification.  

First time with ELRS?

ELRS is cool, but it's not 'fit and forget' like other systems - some knowledge is required in order to configure it correctly. If this is your first experience with ELRS, then please do your research first - see links at the end.

EdgeTX operating system

Unlike the Mk1 and Mk2 which could run on either OpenTX or EdgeTX, the Mk3 is EdgeTX only. 

Firmware version

The review unit came with a pre-release version of EdgeTX 2.12.0. Thanks to the upgraded H7 processor, the Mk3 provides a much smoother experience. Lag when scrolling is considerably reduced, if not entirely absent.

As expected with a pre-release version, there are one or two issues. In particular the UI for navigation is somewhat inconsistent, requiring a mix of touch and keyboard input. Hopefully this be refined in the official release of 2.12. 

A final verdict on the operating system will follow flight testing.

Programming

EdgeTX offers immense flexibility, however, the learning curve is steep. If you haven't used EdgeTX before, please do your research first (the guide provided with the set is not an EdgeTX tutorial). 

Lua script compatibility

One consequence of the larger screen is that some Lua scripts may break, due to invalid assumptions about screen resolution and font size. (I have updated my crow aware trim and channel changer scripts to support the Mk3). 

EdgeTX Companion

At the time or writing, the TX16S Mk3 is not supported in Companion. This has made it a little tricky to migrate a complex F3F setup from my Mk1 to the Mk3, which I needed for flight testing. However, I succeeded after a bit of YAML trickery. 

Hopefully Companion support will be in place by the time the Mk3 hits the streets.

Tip: .ETX files are actually zip archives. To extract YAML model files from a .ETX container, change the file extension from .ETX to .ZIP, then extract. The YAML model files are contained in the /MODELS folder.

Storage for models and settings

The TX16S Mk3 features 4GB of internal flash memory for models setups, sounds etc. This is easily sufficient for normal use.

The unit also accepts a micro SD card, however using a card will disable the internal memory. The card slot is located in the battery compartment.  I can't see much use for a card, except to be able to switch quickly to a backup transmitter. 

Summary

The TX16S Mk3 is solidly built, runs fast and incorporates several improvements over its predecessors. For sure, there are one or two compromises, but overall RadioMaster have done a fine job. 

That said, I always like to flight test a new radio, so the final verdict will await better weather. I especially want to stress test the latest EdgeTX build. The review will be updated once flight tests are completed.

In the meantime, here's a tentative list of pros and cons, using the TX16S Mk2 as the benchmark, and with sailplane/electric applications in mind:

Pros

• Very good build quality
• Excellent AG02 gimbals (MAX version only)
• More rounded and attractive shape.
• H7 processor provides a snappier EdgeTX experience.
• Massive screen
• Great sound quality
• 4GB of internal flash memory - no SD card needed.
• Top switches (SE, SF, SG, SH) are easier to reach.
• Sturdy antenna. No more floppy antenna joints!
• Support for Gemini and Xrossband  (though these are of limited application for sailplane flyers)
• All ports are located at the top.
• Easy access to internals (6 hex screws). 
• Cells are balanced during charging.
• Internal connectors are JST-GH. These have locking tabs, secure yet easy to release.
• Function switches have colour LEDs and are programmable (like TX15).
• New slider position is great for 'thumb' fliers (but see below for pinchers).

Cons

• The carry handle/stand must be extended in order to hold the tx comfortably.
• Slider levers are too short - see here for 3D printed alternative (thanks to @3djc).
• Slider position may not suit 'pinchers'.
• Gemini/Xrossband suffers from a lack of small PWM receivers.
• Pre-release version EdgeTX needs polish
• Flush screen is more susceptible to accidental swipes
• Slightly heavier than Mk1
• Increased current consumption
• No EU/LBT or Companion support at the time of writing

As mentioned, I will update this review once flight tests have been completed.

More images

Click to zoom. If you're on a desktop, you can zoom further by opening the image in a new tab.

Alternative shoulder panels, USB cable, neck strap, softer springs

Top antenna folded back

Top antenna extended

Headphone socket, USB-C, trainer port

Hole for SMA connector (for external antenna).

Expansion bay (shown with author's iRange-X module)

Slider and switches

Motherboard

Shoulder switch assembly

Rear moulding showing RF board 

Antenna routing to carry handle

Links

Note: there are are no affiliate links in this list.

• RadioMaster shop: TX16S MK3 Black / Transparent Charcoal
• RadioMaster shop: TX16S MK3 MAX Black / Red / Blue / Gold
• EdgeTX Clinic - ETX tutorials and templates
• Introduction to ELRS - RC-Soar blog
• RadioMaster TX15 Review - RC-Soar blog

Specifications

• Voltage Range: 6.6 - 8.4V DC
• Working Current: 1.10A (at max RF output power)
• Radio Firmware: EdgeTX (require 3.0.0 or higher)
• Built-in RF Module: ExpressLRS 2 x LR1121 (Gemini & Gemini-X compatible)
• Frequency: ISM 2.4GHz and Sub-G 900MHz
• Number of Channels: Up to 16ch
• Gimbal: V6 Hall sensor gimbals (standard), AG02 (Max)
• MicroSD Card Slot: Yes (card not included)
• Internal Storage: Integrated 4GB of onboard flash memory
• Display: 5-inch IPS touchscreen (800 X 480 resolution)
• Battery: Two 3.7V 18650 Lithium-Ion cells / 21700 Li-ion 5000mAh Battery / 2S 7.4V 6200mAh Lipo (batteries not included)
• Upgrade Method: USB / EdgeTX Companion PC software
• Module Bay: JR-compatible module bay for additional modules
• Dimensions: 200*178*88mm
• Weight: 813g (without battery)