Sunday, 27 October 2019

Jumper T16 Pro - is it ready for prime time?

The Jumper T16 has been attracting an awful lot of attention recently, which should come as no surprise - it's well equipped, runs OpenTx, and is aggressively priced. Droners and sport flyers love it... but is it good enough for high value sailplanes? Could it replace my faithful X9D Plus?

There was only one way to find out, which was to get one and play with it.

A bit of background: I fly sailplanes, both for sport and F3F competition. OpenTX is the perfect o/s for this, and for the last six years I've been a FrSky fan, first with the X9D and more recently with an X9D Plus. Both have been reliable and easy to manage - essential qualities when doing a weekend competition.  In short, the T16 would have to be seriously good to replace them.


The T16’s specification is strikingly similar to the FrSky X10 - they have similar switch layouts, identical screens, and run almost identical variants of OpenTx.

T16 has a same similar spec to X10, but adds an MPM

The big differentiator is the T16's multiprotocol module. This supports more than 50 protocols including DSM2, DSMX and ACCST/D16/D8. The T16 Pro version - which is the subject of this review - has the module inside, leaving the external bay free for an additional JR-style module.

Getting it working: JumperTX or OpenTX?

My transmitter came with JumperTX installed. If the name rings a bell, it's because it's a fork of OpenTx - Jumper created it when the OpenTX developers initially declined to support the T16. However, JumperTX has a major shortcoming in that it's not compatible with OpenTX Companion. This means that setups must be typed into the transmitter, with no means of backing up.

Fortunately the OpenTX devs have had a change of mind - the T16 Pro will be supported in OpenTx 2.3.2 after all. In fact future units will come with OpenTX preinstalled. I therefore decided to get rid of JumperTX and flash OpenTX (a nightly build of 2.3.2). I used the ‘power off’ method familiar to FrSky users.

The next step was to transfer the setups from my X9D Plus, using Companion 2.3.2. No problems were encountered - all my models, F3X templates and Lua scripts work fine.

It works! My F3F setup with adaptive trim script under OTX 2.3.2. Bubbles are from screen protector (my fault!).

Flashing the multi-protocol module (MPM)

The MPM is an open source project by Pascal Langer and is well proven in products such as the iRangeX. It's also very well documented.

After installing OpenTx, the next tasks was to update the firmware in the MPM. Normally this would be done by copying the firmware file to the SD card and flashing from OpenTX. However my MPM didn't have a bootloader, so it was necessary to flash the MPM directly. This required a USB to serial adapter, a custom cable, and the installation of flash-multi software on my PC. The procedure is well described here (thanks Benzo99!) and I had no problems. A bootloader for the MPM was installed at the same time, so further updates will be easy.

I understand that future MPMs will be shipped with the bootloader already installed.

Using the MPM with ACCST

One nice feature is that both EU and non-EU receivers are supported, and I had no problems binding to three receivers, an X8R and RX6R (non-EU), and a G-RX6 (EU-LBT). All worked fine, including telemetry.

Before flying with ACCST for the first time, the MPM's frequency must be calibrated using a FrSky receiver as a reference. The procedure is straightforward, and once the calibration setting is known it can simply be copied into subsequent setups.

The interface between OpenTX and the MPM is well designed - either can be updated independently, and OpenTx will always list the available protocols.

The case 

The case could be straight out of the Futaba catalogue! It’s a good quality moulding with rubberised panels at the side and on the back, and I find it comfortable to hold, though I prefer the slightly chunkier feel of the X9D (I'm a thumber). Unlike the X10, I have no difficulty pushing the sticks into the top inner corner.

The carry handle has a thin moulded grip - a nice little detail. The handle itself projects backwards quite a long way, so extra space may be needed in the backpack.

Top view, showing substantial carry handle

Sticks and switches

The gimbals are Hall effect units. Stick length and tension are adjustable. The sitcks are very smooth, and there's none of the 'creaky spring' sound which I get on my X9D Plus. However stick feel is marred slightly by a curiously asymmetric feel - I prefer the more progressive action on the X9D.

The layout of the switches is similar to the FrSky X10, except that the 6-position switch is replaced by six illuminated buttons. From a programming perspective they work the same. Like the X10, a couple of extra trimmers are provided (T5 and T6) - great for mix adjusters or auxiliary functions.

Top view showing mini-USB and trainer ports

The only complaint is the side levers - the travel is too short for precise control, there's insufficient friction, and the centre detent is too weak. Some users are attaching felt pads to increase friction.

User interface (OpenTx)

The Jumper T16 Pro uses a 4.3 inch 480x272 pixel colour display, just like the FrSky X10 and X12S. It also uses the same widget based variant of OpenTX. It looks pretty, but the default screen is almost bare; it shows just the model name (to which you can add a photo), and small icons for RSSI and battery level.

Default screen is a bit bare.

If you want to show some proper info on the opening screen, you have to configure additional widgets, and this can rapidly get tiresome if you have several models. This is not helped by the less than intuitive navigation system.

I have to say that I much prefer the simpler interface on the the X9D. It may not be as pretty, but all the basic info is just a couple of clicks away - and the monochrome panel consumes less power.

To try and improve matters, I’ve written a widget which displays all the basic info in one pane. You can download the widget from here.

My 'show it all' widget

External module bay

The external JR-style module bay adds a lot of flexibility. For example, you can use a protocol such as Crossfire or M-LINK which are not supported by the MPM. Also, by sharing a module between different transmitters, you can swap tx’s without needing to rebind. Or you might just be happier using your favourite module. (The MPM depends on reverse engineering the various protocols - if you want the real deal, then you must use the appropriate external module.)

Curiously, Jumper skimped a little on the bay’s dimensions - my XJT just module only just fits (after pressing hard), and my M-LINK module refuses to click in place at all. An extra millimeter in depth would have made all the difference.

External module bay with FrSky XJT module

My unit was provided with an empty external module to cover the hole. It looks awkward and rattles, so I made a proper plate for it (downloadable from Thingiverse). I rather like the colour accent from the pink PLA!

Printed module bay cover

The insides

Access to the electronics is easy - just pull off the rubber panels and undo six screws. The internals look very neat and tidy.

The switches are soldered to small daughter boards, so there’s no chance of them working loose or being misaligned. On the downside, it  means that swapping out a switch is not a simple task. So if you like the momentary switch on the left hand side (for DLG), this transmitter may not be for you.

Ribbon cables

Unusually, almost all the interconnections use ribbon cables. On the plus side, it avoids cable clutter, however various users on RCGroups have reported misaligned and even reversed connections. Moreover the sockets reportedly lose their effectiveness after a few insertions. I checked out a couple of the cables on my tx (those with more of the blue leader visible), and while the contacts were fine on both, one of them had not been fully inserted into the socket.

Neat innards. Note use of ribbon cables.

Battery and charging

Power is supplied via two 18650 LiIon batteries (not supplied); these fit into a tray which connects to the tx via a short balance lead.

Takes 2 x LiIon 18650 batteries, requires external charger.

To charge the battery, it's necessary to use an external charger which means accessing the battery and pulling out the cable. This is a bit of a pain, not helped by the battery hatch being rather stiff. In short, the T16 is crying out for USB charging; in the meantime various aftermarket solutions are available.

In summary

The T16 Pro is a radio of contrasts. On the one hand, it's nicely designed and built, feels comfortable in the hand and comes with a good pair of gimbals. The multi-protocol module apparently works well, although I haven't had a chance to test it.

There are some negatives however. These include: lack of USB charging, rather feeble sliders, inflexible switch layout, and (on some units) poorly assembled ribbon cables. And while the colour screen is undeniably nice, the Horus-style user interface feels cumbersome compared to the X9D.

There is also a question about the operating system: JumperTX looks like a dead end, while OpenTX 2.3.2 is still under development. At the time of writing I do not regard the T16 as flight ready.

Overall, though, it's a thoroughly modern transmitter at a remarkably low price (around £145 at the time of writing). However I would wait until it ships with OpenTx, preferably the production or release candidate version.

Finally, if you wanted to know if the T16 is replacing my X9D Plus... well the answer is that I haven't decided yet. The T16 Pro is more modern, but my old X9D+ still hits the sweet spot with excellent ergonomics and a rock solid version of OpenTx. More time, and some flight testing needed - watch this space.


Anonymous said...

I have done a very easy internal charger for it to use the built-in usb. I did it with the old version without internal module, but all that’s needed is to place the charging pcb under the transmitter module.

rumbey said...

Interesting Mike

Im nearly ready to buy this. Probably early 2020 once a few features are sorted

Anonymous said...

Where can we get the widget script "show it all" can you share it?

RC Soar said...

Yes it'll be shared on OpenTX Clinic once it's fully shaken out.

Vladimir said...

Thank you for the MPM bay cover. Nice piece of art... :-)))

William Parker said...

May I please request you to share the Show it all widget as is, for the time being. Just as we use the openTX nightlies would it not be good to keep working with it while you're shaking it out? Honestly I'm being selfish. One look & I simply must have it. It's that good.

RC Soar said...

The Show It All widget is now available from OpenTx Clinic