Friday, 31 July 2020

RadioMaster TX16S review: can it crush my X9D Plus?

It's a great time for OpenTX fans! While FrSky still dominates with its proprietary systems, new manufacturers like Jumper and RadioMaster are offering an alternative path. 

One such transmitter is the RadioMaster TX16S, a full feature radio at a budget price. The centrepiece is its built-in 4-in-1 multi-protocol module (MPM), a clever gismo which works with different brands of receiver including FrSky, HOTT, Spektrum and Futaba. 

The TX16S is an interesting transmitter, but can it succeed where the Jumper T16 failed, and replace my old faithful Taranis X9D+? Read on and find out!


RadioMaster TX16S
RadioMaster TX16S
Full disclosure - RadioMaster sent me this unit free of charge to evaluate and keep. RM did not seek or receive access to this review prior to publication, and all opinions are my own. 

Roots and branches

RadioMaster may sound like a new company, but it was formed from the team which produced the Jumper T16. No surprise, then, that the TX16S bears more than a passing resemblance to the T16 Pro (a radio which I also own).

Similar spec, different character: Jumper T16 Pro(left) and RM TX16S
Similar spec, different character: Jumper T16 Pro (left) and RadioMaster TX16S

Another transmitter which looks similar is the Jumper T18, however I won't mention it further as it is reported to suffer from reduced range on 2.4 GHz due to the antenna arrangement (an indirect result of its support for R9).


What's in the box

The first surprise is the packaging. Instead of the usual polystyrene, the TX16S comes in a semi-rigid foam case with the RadioMaster logo embossed on the lid. It fits like a glove and is perfect for slinging in the back of the car. 

Semi-rigid foam case
TX16S as delivered


The following accessories were supplied: 
  • Neckstrap with the 'RadioMaster' logo + carabiner clip
  • Quick Start guide
  • 1 meter USB-C charge/data cable
  • 4 x gimbal springs. These are softer than the ones already fitted.
  • Sticker sheet (I'm a sucker for these!)
  • Key ring (cute!)
All hardware is of decent quality, however, the carabiner clip will inevitably scratch the screen, so I've kept the screen protector in place for now.

Styling and ergonomics

The plastic shell has a smooth semi-matt finish. Fit and finish are good, and I think it looks rather smart.

The side and rear grips are made of a flexible plastic. Compared with the Jumper T16, the material is less tactile, however the rear grips are deeper and there's a useful finger rest near the top. The grips may seem less comfortable on first acquaintance, but ultimately they provide a more stable hold.

Rear grips T16 left, TX16S right
Rear grips T16 (left) and TX16S.

The power switch is 'soft' and incorporates a 3-colour LED: blue for transmit, red for transmission blocked, and green for charging. There's a delay when powering on and off. The 'off' delay is adjustable in OpenTX (being impatient, I have it shortened it to 1 second in the Sys/Radio menu).

The unit balances nicely with a neck strap when using 18650 cells.

Power switch
Power switch and neckstrap point

Switches, knobs and sliders

[If you're already familiar with the T16, T18 or X10 then you can skip this section as they're all pretty similar in terms of knobs and switches....]

Eight switches are provided – six 3-position and two 2-position at the rear. The switches have a decent action with minimal play. All switches are mounted on daughter boards for stability - the downside is that swapping them around will involve some tricky soldering. 

In common with its peers, the momentary switch is at the rear right, not the best place for right-handed DLG pilots.

The TX16S switches have a nice feel
Switches have a nice feel


There’s a slider on each side. They're not great - too little friction and too short throw - but they are usable (I use the left slider for motor control).

TX16S Sliders
Sliders are not the TX16S's strong point


Near the top are the two analogue knobs (S1/S2). They're quite small and a little fiddly, but usable. 

Below these are six illuminated 'chicken feet'. These behave as radio buttons (one button is active at any one time), and are programmed as a 6-position switch. 

Below the chicken feet are the auxiliary trimmers (T5/T6). These could be programmed as mix adjusters for rates, diff etc.

Access to the programming menus is via six buttons and a roller. Unusually, there are two Page buttons, for forward and back (personally I have got used to a single Page button and a short/long press, but some may prefer the extra button). The lettering on the four black buttons is embossed, and is not so easy to read.

The roller is made of metal with a knurled finish. It has a nice weight, and a pleasant click action - much better than the 'dead flesh' action on the T16. 


TX16S roller, made of knurled metal
Knurled metal roller

Looking inside

One of the first tasks will be to adjust the stick tension, ratchet action etc. To do this, you have to open the case. This is accomplished by peeling off the side grips and removing six screws (four cross-head screws at the back, and two Allen head screws on the antenna plate). The tensioners are adjusted with an Allen key - clockwise weakens the tension.

For the throttle axis, the usual ratchet and friction adjustments are provided.

This is a good opportunity to examine the rest of the insides. It all looks very neatly organised, with good use of cable ties, and the gimbal wires are well supported at the junction with the sensors. 

[Note that new sets have an extra speaker on the rear moulding, with a lead to the motherboard. Some extra care will be needed to separate the two halves.]

The SD card is accessible via a rubber flap in the bottom of the case. Care is needed when inserting the card - if you get it wrong it can slip inside the case.



A view of the electronics


Multi protocol magic!

The TX16S comes with a 4-in-1 multi protocol module (MPM), derived from the well proven open source project.

The emulations are all reverse engineered, so don't expect any endorsement from the original manufacturers. However problems are rare, and generally quickly fixed.

The list of supported protocols includes FrSky, Spektrum, HOTT, Hitec and Futaba SFHSS. Importantly, each model can be configured with its own protocol.

Operation with FrSky receivers

The MPM will work with FrSky receivers on D8 and D16, LBT and FCC. Both the v1 and v2 versions of D16 are supported. All these options can set on a per-model basis. The resulting flexibility is far greater than FrSky themselves offer. (With FrSky transmitters, most options are set in firmware and cannot be varied from model to model.)

Note however that FrSky's new ACCESS protocol is not supported, and it's unlikely that it will be.

Frequency calibration

If using FrSky protocols, the MPM's frequency must be calibrated using a FrSky receiver as a reference. The procedure is quite straightforward. The MPM documentation suggests that the calibration need only be done once and the setting copied to other models, however I have found that receivers do vary - I now calibrate for each receiver individually.

Cloning another FrSky transmitter

Although ACCESS is not supported, the MPM emulates one its star features, namely the ability to switch seamlessly with another transmitter - without rebinding! It can do this thanks to a special 'RX Clone' mode where it can bind to another transmitter, and capture its global ID. It can then be configured to transmit using the cloned ID.

Cloning is a great feature. After cloning my X9D Plus, and copying my setups using the Companion software, I was able to use the TX16S on all my models with minimal reconfiguration - and without the need to access the receiver to rebind. And not having to rebind is great if you need to switch quickly to a backup transmitter.

Cloning is available in more recent versions of the MPM firmware. OpenTX 2.3.9 or later is required.


Screenshot of MPM  configuration with D-16 clone mode enabled
The MPM can clone another D8 or D16 transmitter for seamless swapping


Spectrum analyser

The MPM has a spectrum analyser function, accessible from the OpenTX 'Tools' menu. 


Spectrum analyser function
Spectrum analyser function

External module

In addition to the MPM there's an external JR-style bay, so you can use an original FrSky, M-LINK etc. module if needed. Support for telemetry will depend on the protocol.


Batteries and charging

There's a generously sized battery bay with a holder for two 18650 cells. A rubber pad under the cover prevents the batteries from rattling around. 

TX16S and T16 Pro battery compartments compared
The TX16S (left) has a larger battery bay compared with T16


For those who fly all day and every day (I wish the weather in the UK allowed that!), the bay will accept two 21700 LiIon cells with a typical capacity of 5000 mAh. Ready made packs are available.

An internal charger provides balanced charging for two LiIon cells, with overload and temperature protection. Charging is very simple - just connect the transmitter to a USB source using the supplied cable. The power switch LED goes green, and turns off when charging is terminated. I simply leave mine to charge overnight.


Bottom ports
Bottom ports from L-R: UART, USB-C charging, SD slot, UART. 


Sticks / gimbals

The gimbals feature Hall sensors. They are beautifully smooth. Tension feels uniform and linear in all directions (yes, you'd think that would be a given... but the gimbals on the Jumper T16 fail this test due to poor gimbal geometry).

The tension as delivered was a little too firm for my taste, and I reduced it by loosening the tension screws as described earlier. For those who like their sticks even softer, a packet of 'soft' springs is provided - now how's that for attention to detail!

The sticks can be adjusted for height after releasing a grub screw in the top. 


Stick top
Stick top

Gimbal detail
Gimbal mechanism

On my unit, there was a calibration drift of +/-1% on each stick axis. Slightly annoying, and I have passed on this observation to RadioMaster. 

The sticks are also canted inwards very slightly (approx 1mm each at the tips) when centred, apparently due to a misalignment of the centring bar. It doesn't affect calibration and I haven't found it to be an issue. Another little oddity is that the gimbal markings apply to the horizontal-axis, rather than the usual ratchet axis.

Minor niggles aside, these are very nice sticks, and I would have no hesitation in using them for competition. 

Sound

Speaker volume on my unit is best described as adequate. I had no problem in a light breeze, but suspect I may struggle in anything stronger. [edit: new sets come with an extra speaker - see comments.]

Speaker grill
Speaker grill.


Screen

The LCD panel is a 4.3” colour device. It's touch-capable, however we won't see the benefits until the next major release of OpenTX (version 2.4).

As with all the colour-screen tx's I've used, I had some difficulty in bright sunlight. This time though, I decided to investigate to see if it could be improved. It turns out the problem is not so much the panels, but the confusing graphic in the default OpenTX theme. Happily, it's a two-minute job to suppress the graphic, as described in this post on RC Groups. The result is a colour scheme which is much more readable.


Screenshot of 'Show It All' widget
Show It All widget after the theme mod (see text)


Following my post, one of the lead OpenTX devs is creating a new 'Green' theme (thanks 3djc!).

OpenTX operating system

My TX16S came with OpenTX 2.3.8. It works straight out of the box - there's no need to flash to a newer version unless you need the MPM's 'clone' feature. For programming on the PC and for data transfer, it'll be necessary to download the latest version of Companion.


Data transfer port (USB-C)
USB-C port at left is for file transfer and flashing OpenTX

Telemetry and other data are displayed using 'widgets'. A number of widgets are supplied as part of the operating system, and others are provided on the SD card, as Lua scripts. You can choose which widgets to display, and how much screen space each one should occupy, all of which allows you to build highly customised screens. If you're into programming, you can write your own widgets in Lua.

Widgets are a great idea, but configuring them can be tiresome. To get you going quickly, RadioMaster have included my Show It All script which shows all the basic info in a single widget.

Another useful widget is BattCheck for monitoring your motor battery. These two widgets may be all many pilots will need.

Flight testing

So far I’ve had around ten hours flying, using three models:
The MPM configuration in each case was FrSkyX1 / D16 (clone), FCC. 

Test flying at Ivinghoe Beacon
Author with Pike Precision 2 at Ivinghoe Beacon

Flying has been uneventful, except for a single low RSSI warning when flying the Pike Precision. Bear in mind that this is a carbon rich model with a less than optimal antenna arrangement.

Additions

As I intend to use the TX16s regularly, I’ve made a few tweaks:
  • Replaced the fixed handle with a Jumper folding handle (fits perfectly).
  • Made a slimline Correx box (to fit in the backpack)
  • Added custom stick tops.
With folding handle from Jumper T16
Folding handle from Jumper T16 fits perfectly

Author's custom Correx box
Author's slimline box from Correx.

Conclusions

It's clear that RadioMaster have put a lot of thought into the TX16S, rather more than one might expect at this level. While it’s not perfect, it gets the important things right, with good ergonomics, very nice sticks and a simple and effective charging system. And at around £120 it represents excellent value.

For FrSky users, the MPM allows you to mix and match protocols. And thanks to the ‘clone’ feature, you can seamlessly swap between the TX16S and a FrSky transmitter. For non-FrSky users, the TX16S offers a low cost entry into the world of OpenTX.

Of course, the TX16S isn't going to suit everybody. For FrSky users who want to use genuine RF modules or who wish to migrate to ACCESS, an X10 or X9D Plus 2019 would be a better choice. Also, right handed DLG flyers will find the momentary switch on the wrong side. 

So how does it compare with my X9D Plus? In spite of their age the X9D and its derivatives remain very good radios for soaring. They may seem a little basic with their mono screens and stripped down user interfaces, but they are compact and reliable workhorses with good sound. On the other hand, the TX16S is more modern, and just feels more desirable. It's a tough choice! As for me... suffice to say that the TX16S is the first transmitter with a colour screen that I actually enjoy using.

Whether the TX16S replaces my X9D Plus will become clearer with time. In the meantime, I finding myself instinctively reaching for the newer radio. I just really like using it!

[Edit 16 Sept 2020: My TX16S has just had its competition baptism at the 2020 Welsh Open F3F, controlling my Pike Precision 2 for all three days of flying.]

Top view of FrSky X9D Plus and RM TX16S


Front view of FrSky X9D Plus and RM TX16S
Decisions! My trusty X9D Plus (left) v. the young pretender





11 comments:

Tronix123 said...

Really excellent Review .. touches on all the key Pro's and Con's. I have an RM TX16S and do like it a lot myself..
Thanks ,,
JimS

RC Soar said...

Thanks Jim! Looking forward to putting in some more hours.

Unknown said...

Owen from radiomaster ,we already added one more speaker on the back of the radio .Sound is fine now .For the sliders ,we are will consider how to improve the travel .

RC Soar said...

@Owen: Good to know, thanks... appreciate RM's engagement with users.

raknin said...

Hi

I will get mt radiomaster hall version soon. Di
Oes radiomaster will send the upgrade speaker to existing user?

Paul Stubley said...

Hi Mike
Really enjoyed reading your excellent report here.
I took delivery of a TX16S at the beginning of July and as my first Open TX transmitter and am now on a steep learning curve! My main factor for buying was due to the obsolescence of my trusty Hitec Aurora 9 TX and for which I had a lot invested in top of the range Optima 9 receivers in my F3f fleet and many other aircraft. So on receipt of the TX16S, my first task was a bench test binding to Hitec Optima receivers. The smile on my face could be seen for miles when all proved out successfully.
Prepare for lots of questions on the hillside at the comps! ;-)
Cheers Paul S.

RC Soar said...

@Paul: great, look forward to swapping notes on the slope :)

rumbey said...

Spot on review Mike. Had this on my radar for a few months now. Having confirmation that it's fully compatible with your f3f scripts and the Clone feature has swayed it for me. I may have it for this years Welsh Open.

Clive Jones said...

Good "warts and all" review. The small negatives (which seem to be being addressed) would not put me off buying one when the time comes to replace my less well equipped but satisfyingly capable QX7.

Bill Glover said...

An excellent real-world review. I'm still happily using an original X9D Taranis (to which I've added Hall effect gimbals, haptic and a better speaker), but I always keep a replacement/upgrade on my RADAR in case I need one in a hurry ... and that is currently the TX16S.

One small thing to be aware of is that the CC2500 RF chip in the MPM runs at a lower power setting than in OE modules, which will give slightly reduced range (I've seen this estimated at 90%) on protocols that use it - FrSky, Hitec, Graupner HoTT and Futaba SFHSS are the main ones. With modern receivers and decent installation this should be insignificant for LOS flying though.

RC Soar said...

@Dave, Clive and Bill: thanks for your comments!