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 well for over five years, for sport and F3F competition.

Times change, though, and the design is starting to show its age: the processor struggles to keep up with EdgeTX, and the MPM is no longer the 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

The Mk3 is a conventionally styled high end transmitter. While the general layout is similar to the Mk2, the shell is all new. 

Key features are derived from other units: the Gemini RF module comes from the GX 12, while the H7 processor is from the TX15. 

As with other RadioMaster tx's, the TX16S Mk3 is available in two versions. 

• Standard, with regular gimbals and a plain finish. 
• MAX, with AG02 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

Unboxing a new radio is always fun, and the TX16S Mk3 was no exception! The first thing to greet you is RadioMaster’s signature carry case, with the transmitter packed inside.

Before we move on to the transmitter, a few words about the carry case. It's a quality item, made of semi rigid foam with a tough fabric finish. It lacks a zipper pocket however there's a stowage area next to the tx. The overall size of the case is 270 x 250 x 105 mm.

Semi-rigid padded case.

Included in the stowage area are the following:

• 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

Okay, so let's move on to the transmitter! 

The TX16S Mk3 MAX looks and feels like a premium product, and it has the build quality to match. Fit and finish are good, and it feels reassuringly solid in the hand.

The first thing that strikes you is that huge on/off switch... it's going to be controversial, but I love it!

The faux carbon finish looks smart and is flawlessly applied. The side cheeks are made of a leatherette material 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 switches and controls work smoothly. 

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

The shell

The new shell is all curves and rounded edges. In terms of ergonomics, the biggest change is the grip. On the Mk1, your fingers glide over a prominent ridge at the back, so you can choose your own grip style. On the Mk3, your fingers fall into a valley for a more locked in feel. Which is the better grip will depend on personal preference.

Multi-purpose handle

The folding handle is unusually sturdy, which make sense when you realise that it has a second function: it also houses the second antenna. 

Carry handle houses second antenna.

When extended, the handle can act as a stand. On a flat surface the radio sits at the perfect angle for programming.

Rather annoyingly, the handle rests over the grip when retracted. This means you have to extend the handle 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 fine when using 18650 batteries.

Switches and controls

Let's take a look at the switches and controls:

Switches

The switch layout is similar to the Mk2, though with subtle tweaks, for example I find the top switches (SE - SH) are easier to reach on the new set. 

Here's a quick summary:

• 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

Just like the Mk2, the motherboard will accept two two additional momentary switches SI and SJ, however these will require holes to be drilled in the case.

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. They are smooth with a positive centre detent. The new location is okay for thumbers, however pinchers 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 find them difficult to manipulate precisely. A longer arm is available for 3D printing, see link at end.

Trims

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

Main trims

As with previous versions, there are two auxiliary trims designated T5 and T6. These are treated by EdgeTX as regular controls. As with the primary trims, these trims can store different values according to the flight mode.

Auxiliary trims T5, T6

Programming controls

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

The SYS and MDL keys sit closer to the edge than the Mk1/Mk2 and are more prone to inadvertent operation. It's not an issue in normal operation, but something to be aware of when holding one handed, for example when carrying the model or launching a DLG.

Function switches

Above the screen is an array of six buttons SW1 - SW6. These look similar to those on the Mk1/Mk2 except they are 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 RadioMaster's latest AG02 gimbals. These are CNC units, and have a smooth, refined feel.

Compared with the AG01, there are some differences. The obvious one is the design of the faceplate - it’s more restrained than the older unit. More importantly, the stick limits can be adjusted in both horizontal and vertical axes. 

Also, the connectors are JST GH. Unlike the AG01 connectors, these have locking tabs. When sold separately the AG02 comes with adapter cables for compatibility with the RadioMaster 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, a great feature as it means that adjustment can be carried out on the field.

Softer springs are provided in a separate bag. 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 using an allen key 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. 

One curious oversight (may not apply to all units): when adjusting for maximum friction, the adjustment screw protrudes enough to interfere with the throttle movement - the effect is to raise the idle end stop slightly. The cure is to grind off around 1mm from the end.

Side cheeks removed.

Adjusting travel limits

Unusually, the travel limits 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 the limits will also reduce the resolution. If you want to reduce the travel in both axes, a better option is just to screw down the sticks. 

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 readable even in bright sunlight.

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 occasionally found myself 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 has little 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. However, there is no built in way to detect shake gestures (tilt acceleration) which rather limits its usefulness.

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 new feature. 

Gemini RF module

The Mk3 features an upgraded RF module. Maximum output is 1W and it incorporates a heatsink and fan. Given the low ouputs (typically below 100mW) used in F3/F5x applications it's unlikely the fan will see any use.

Gemini-X RF board

The module 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. Let's take a look at the transmission modes in more detail:

'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 and is the one that I used for flight tests:

• 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 stronger 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, where 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 improved.

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 came 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 (yes, some people are still using the older operating system on their Mk1 and Mk2's). 

The review unit came with a pre-release factory build version of EdgeTX 2.12.0. The Mk3 is supported in 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 some 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, then do some 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. I can't see much use for a card, except to be able to switch quickly to a backup transmitter. The card slot is located in the battery compartment.  

Flight tests

So far I've had a single session with a 3m F3F slope sloper. Total flying time 30 minutes... just long enough to get a feel for the tx. Max distance was around 250 meters.

The transmitter felt good in the hand and I gelled with it quickly. For maximum security touch was disabled during flight.

The logs tell an excellent story! Tx power was steady at 10mW with very occasional spikes to 25mW. Link quality never dipped below 98%. All in all, it felt pretty effortless. Test conditions as follows:

Model

• Sting F3F

Hardware

• TX16S Mk3
• ER6 receiver
• GPS sensor

EdgeTX

• Companion 2.12.0 rc3
• EdgeTX pre-2.12.0-selfbuild (as installed in review unit)

ELRS config

• ELRS V4.0.0 EU/LBT with Arming mode = Switch
• 100 Hz / 8Ch full, Antenna mode='Switch'
• Dynamic RF = On
• Max Power = 100mW

Model template

• F3F

Widgets

• ShowItAll
• Crow aware trim
• GPS-F3F tracker

Summary

The TX16S Mk3 is solidly built, comfortable to hold and incorporates several improvements over its predecessors. It's undeniably an impressive piece of hardware. 

As with any advance, though, you have to lose to win - and there are one or two compromises. 

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 may feel too short - there's a 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

Who's it for?

The TX16S will appeal particularly to:

• TX16S Mk1 / 2 users looking for a snappier and more modern experience
• Pilots looking for a quality radio with dual band capability

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