RadioMaster TX16S Mk3 review

The TX16S has been a huge hit for RadioMaster, thanks to its blend of capability, reliability and value. Indeed my own Mk1 has served me faithfully for  over five years, for both sport and F3F competition.

That said, the design is starting to show its age: the processor struggles to keep up with EdgeTX, and the MPM is no longer the RF module of choice for many pilots.

Enter the TX16S Mk3, RadioMaster's new flagship radio, with Gemini RF module and fast H7 processor. Read on and find out if it's a worthy successor!... 

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

Although the TX16S Mk3 is quite different from the Mk2, some key features are derived from other units. In particular  the Gemini RF module comes from the GX 12, while the H7 processor and AG02 gimbals were first showcased in the TX15. 

The Mk3 is available in two versions. 

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

The unit provided for review is a MAX version.

RadioMaster TX16 Mk3 MAX

Carry case and accessories

My package arrived safe and sound after its journey from China. Inside the package was an attractive display carton. Contained within the carton was a smart carry case, with the radio nestling within it.

The carry case is made of fabric covered foam. It lacks a zipper pocket (as on the TX15), however there's a stowage area to the left of the transmitter.

Semi-rigid padded case.

Included are the following accessories:

• Alternative shoulder panels (without slider slots)
• Blanking plugs for unused switches
• Nylon neck strap
• Battery tray for 18650 batteries
• Set of soft gimbal springs
• Allen key for adjusting spring tension
• Grub screws for stick ends
• Quick Start guide (contains useful information about batteries etc.)
• Stickers

Some of the accessories

Build quality

The TX16S Mk3 MAX looks like a premium product, and it has the build quality to match. It feels dense and well screwed together, with no rattles or squeaks.

The shell has a faux carbon finish, nicely applied and rather smart. The leatherette side cheeks are edged with decorative stitching in the same colour as the CNC items. 

Robust antenna hinge

The hinges for the top antenna and handle have just the right amount of stiffness and feel robust - a big improvement on the floppy antennas on the Mk1 and Mk2.

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

General ergonomics

Does the Mk3 match up to the excellent ergonomics of its predecessors? Let's see...

The shell

The new shell is all curves and rounded edges. Compared with the Mk1, the main difference is the grip. On the Mk1, your fingers glide over the ridge at the back, so you can choose your own grip style. On the Mk3, your grip is more locked in. Is it more comfortable? For me, it's just different.

Carry handle/antenna housing

At the back of the shell is a sturdy folding handle. It also houses the second antenna. 

Carry handle houses second antenna.

When folded out, the handle can also act as a stand. On a flat surface the radio sits at the perfect angle for programming - a nice little convenience.

Rather annoyingly, when retracted the handle rests over the grip. This means that it must be extended in order to hold the tx comfortably.

Carry handle sits over grip when folded.

Weight

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

Switches and controls

Let's look in more detail at the switches and controls:

Switches

The switch layout is essentially the same as the Mk2, with only subtle changes. That said, I find the top switches (SE - SH) are easier to reach on the new set. To summarise: there are eight switches: 

• 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

Let's not forget that huge on/off switch... it's a grand statement, and I love it!

Pots

There are two pots designated S1 and S2 near the top of the unit. They're similar to the Mk2, smooth acting with positive centre detents. 

Sliders

The sliders LS and RS have been moved from the side to the rear. For thumbers this is a welcome change. Pinchers, on the other hand, may find the new position somewhat challenging. 

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

One thing I noticed: the slider arms are very short, and I found them difficult to manipulate. A longer arm is available for 3D printing, courtesy @3djc. You can download the STL file from here.

Trims

The primary trims are nicely placed, and a little more prominent than on the Mk1 and Mk2.

Main trims

There are two auxiliary trims designated T5 and T6. These are treated by EdgeTX as regular controls. Like the primary trims, the aux trims can store different values according to the flight mode.

Auxiliary trims T5, T6

Programming controls

The programming follow controls follow the usual RadioMaster convention. The buttons have a nice positive feel and are clearly labelled.

Function switches

Above the screen is an array of six buttons SW1 - SW6. These look similar to those on the Mk1/Mk2, but there's a big change: they're now programmable.

Programmable function switches

The buttons are programmed 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. 

Now here's a nice EdgeTX feature: a button  press can be simulated in EdgeTX using the 'Push CS' special function.

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

The gimbals

The Max features the latest AG02 gimbals. These are CNC units, and have an excellent feel.

Compared with the AG01, there are some minor differences. The AG02 has travel is adjustable in the horizontal as well as the vertical axis. Also, the connectors to the motherboard are JST GH (when sold separately they come with adapter cables, so they can be used with the Boxer and TX16S Mk1/Mk2).

AG02 gimbals. Sweet!

The AG02 exhibits very low noise, and the ADC filter in EdgeTX is disabled by default.

Adjusting tension 

The gimbals came with hard springs installed. Adjustments to tension and travel can be made from the front of the gimbal - no need to open the case.

Softer springs are provided in a separate bag. Note that changing the springs needs a little care, so as not to deform them. The secret is to relax the springs to the minimum, and to use fishing line to manipulate the top loop.

Changing stick mode

Swapping between mode 1 and mode 2 is achieved by engaging or releasing the throttle spring, and this can also be done from the front face of the gimbal.

Adjusting the throttle ratchet/friction

The throttle axis is adjustable for both ratchet and friction. The adjusters are accessible after removing the side cheeks. 

Side cheeks removed.

Adjusting travel

Unusually, the end points can be adjusted on both the horizontal and vertical axes. The adjustments are made from the front - there's no need to open the case. After adjustment the sticks must be recalibrated via the System>Hardware menu.

Note that reducing travel will also reduce the resolution of the gimbal. If you want to reduce the travel in both axes, a better option is just to screw down the sticks. 

All in all, the AG02 is an excellent gimbal.

The screen

One of the star features of the TX16S Mk3 is the 5-inch IPS screen with 800 x 400 pixel resolution. After the Mk1 and Mk2, it looks huge. 

Mk1 (left) compared with Mk3

Text is easier to read, and there's more info displayed on each page. The screen is bright too. While I haven't tried it yet in bright sunlight, I'm confident that it'll be perform.

Tip: some pilots may find the EdgeTX graphic confusing. Fortunately there's a simple 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!

Touch screen sensitivity

On the Mk1 and Mk2, the screen is recessed behind a bezel which affords some protection against accidental swipes. 

By contrast, the Mk3 screen is flush with the shell. When using the roller, I found myself accidentally brushing the screen, which can trigger an unwanted action. A little more care is therefore required when using the roller.

Tip: touch can be disabled automatically when you're flying. To do this, create a special function, and set the trigger to 'Tele'. After this change, touch will be disabled while telemetry is active, for  security against accidental changes.

Ambient light sensor

Located between knobs S1 and S2 is an ambient light sensor which automatically adjusts screen brightness according to the surroundings. The sensor is activated using the 'Backlight' special function with the 'Ambient light' option. 

The idea is good, but it didn't seem to have much effect on my unit.

Sound

Sound on the review unit is excellent - at maximum volume the speaker is commendably loud with no distortion.

Tilt sensor

The TX16S Mk3 features a 2-axis tilt sensor. These appear in the source lists as TltX and TltY and return the tilt angle. If you want to detect shake gestures (tilt acceleration), this will involve 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 on the Mk3 incorporates a balancing circuit - a worthwhile improvement. 

Gemini RF module

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

• Standard ELRS (single frequency)
• Gemini (single band/dual frequency)
• Xrossband (dual-band)

2.4 GHz or sub-900 MHz operation is supported in all modes. 

Gemini-X RF board

Maximum RF power is 1W, and there's 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.

Let's take a look at the transmission modes available:

'Standard' ELRS mode

Most sailplane pilots will be using receivers such as the RadioMaster ER6, ER6G, ER8G etc. For these, only a single transmit path is used. The following configuration is well proven:

• Packet rate: 100 Full 2.4G or 333 Full 2.4G
• Antenna mode: ANT1 or ANT2 or Switch (do not use Gemini mode!). 
• Switch mode: 8ch
• Max power: 100mW
• Dynamic RF: On

When using Switch antenna mode, both antennas are used, transmitting alternately. 

When receiving telemetry, regardless of antenna mode, both antennas operate and the better signal is used ('antenna diversity').

Note: RadioMaster recommend that the top antenna be rotated 90 degrees when using Switch antenna mode.

Top antenna rotated 90 degrees

 

Gemini and Xrossband modes

Also supported are Gemini and Xrossband. With both these modes, each packet is transmitted simultaneously over parallel transmission paths. Gemini is single-band (2.4 GHz or sub-900 MHz), while Xrossband is dual-band (2.4 GHz and sub-900 MHz). 

The result is better link quality (fewer dropped packets) compared with standard ELRS, in areas with high levels of interference. Note, however, that maximum range is not affected.

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

While the new modes will be welcomed by drone pilots, I feel that they will be of limited interest to sailplane flyers, at least for now. 

This is partly because regular ELRS is good enough for most sailplane 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 tools.

The RF module came with v3.6.3 FCC firmware, and I have since updated it to v4.0.0 LBT. The ExpressLRS script was already installed and accessible from the System>Tools menu.

First time with ELRS?

ELRS is well proven, 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. 

The review unit came with a pre-release factory build version of EdgeTX 2.12.0. This works fine with  Companion 2.12.0 RC3. 

Performance

Thanks to the upgraded H7 processor, the Mk3 provides a much smoother experience. Lag when scrolling is considerably reduced, though 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.

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

Lua script compatibility

One consequence of the higher screen resolution is that some Lua scripts may break. 

I have updated my crow aware trim and channel changer scripts to support the Mk3. My F3F GPS tracker script is already compatible. 

Ease of 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!). 

Flash memory 

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, comfortable to hold and incorporates several improvements over its predecessors. In short, it's an impressive piece of hardware. 

As with any advance, though, you have to lose to win - and there are one or two compromises. Whether they matter will depend on your particular application. 

Bearing in mind that flight tests are not yet completed, here is my preliminary assessment:

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)
• Dual antennas offer benefits, even in non-Gemini mode
• 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 RGB colour LEDs and are programmable (like the 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 arm is 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 lacks polish
• Flush screen is susceptible to accidental swipes
• Heavier than Mk1

A personal wrap

So... will my Mk1 be gathering dust from now on?

In truth, my Mk1 continues to be rock solid running OpenTX and MPM. So, I'll need some persuading before making the jump to a new operating system and hardware, especially since F3F competition is a particularly demanding environment.

As soon as the weather allows, I will be stress testing the Mk3 with a complex F3F setup (55 mixes)  and multiple Lua scripts. 

Watch out for an update after flight tests!

More images

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

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

Stickers, quick start guide and screen protector

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)

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
• RC-Soar.com - author’s website
• EdgeTX Clinic - ETX tutorials and templates
• ELRS Gemini - what is Gemini?
• Introduction to ELRS - RC-Soar blog
• RadioMaster TX15 Review - RC-Soar blog