Thursday, 11 July 2013

FrSky Taranis - review and photo gallery

FrSky's new transmitter, the Taranis, continues to generate great interest. It has many advanced features, yet it's very aggressively priced at a shade under £160 / $210 - and that includes an 8-channel receiver with built-in telemetry.

One way FrSky have kept the cost low is by adopting OpenTx as the operating system. OpenTx is open source, so FrSky did not have the expense of developing an operating system from scratch. Don't be fooled by the 'open source' label, though - the OpenTx is without doubt the most flexible o/s of any transmitter on the market.

For this review, I'll concentrate on the transmitter hardware.

FrSky Taranis set contents
FrSky Taranis transmitter and accessories. (Note long-range antennae on X8R receiver. Normally it's supplied with regular antennae.)

Opening the box

The Taranis comes in an aluminium flight case with just a layer of corrugated cardboard to protect in from the outside world. Supplied with the tx are a 800mAh NiMH battery, X8R receiver, neckstrap, and mains adapter.

Picking up the transmitter for the first time, it was hard to avoid a sense of deja vu - it has the feel and style of those classic JR transmitters of years past. The form factor was originally designed for 35 MHz, so inevitably there are one or two compromises which we'll look at.

FrSky Taranis transmitter
FrSky Taranis transmitter

Styling aside, the box itself is quite comfortable to hold, and the quality of the moulding is pretty good. The Taranis may be relatively inexpensive, but it doesn't feel cheap.

Aerial and module bay

To provide correct balance with the small 2.4 GHz aerial, FrSky have thoughtfully provided a balance arm for attaching the neck strap. Unfortunately the arm partially obscures the on-off switch. If you've got big fingers, you  may find a more suitable balance arm on eBay. Also provided is a rather cheap feeling metal clip for attaching the neck strap to the arm. I have a feeling this will end up scratching the display so I will replace it.

In addition to its internal XJT module, the Taranis will also accept a separate external module, providing a very convenient way to use your existing DSM-2, DSMX etc. receivers. Note that the existing aerial cannot be removed. Selection of internal/external module is on a per-model basis via a firmware menu.

Sticks and switches

FrSky are highlighting the quad ball-raced gimbals - and with some justification as the sticks are very nice units, with a smooth feel. Stick tension was a little weak out of the box, but this was easily corrected using an allen key (not supplied). There have been one or two reports of double-centring in the first production batch, but mine are fine.

In spite of its compact size, the transmitter is chock full of knobs and switches - twelve in all. This is great news for scale modellers, but way over the top for most glider guiders. The switches are also quite closely spaced, so the ones you don't use just get in the way.

Fortunately, FrSky have designed a very open layout, so removing or replacing switches is not a major job. Options for ergonomic freaks: (a) re-locate the switches to taste, (b) remove unused switches, and (b) replace some of the 3-position switches with 2-position types (but note, not the other way around).

The physical 'feel' of the switches is a little harsh. I cured this by slipping some lengths of silicon fuel tubing over the stalks. The switches do seem pretty robust though.

The side levers have a slightly 'slithery' feel, with weak centre-detents. I couldn't find an easy way to adjust them so have left them as is. I'll get used to them - probably by not using them.

Taranis internals


The display panel is a decent size. Readability in daylight is only average though - contrast is quite low and the panel suffers from reflections - those coming from Multiplex radios will notice a difference.  The panel is not in the best location (bottom of the case, partially obscured by neck strap), though thanks to voice feedback there's probably less reason to look down anyway.

The panel has a backlight for use in dim light. This is controllable via a menu option, or you can assign a switch.

Programming interface

Programming is by means of six buttons located to the sides of the display. There's no rotary encoder ('digi-adjuster' in MPX parlance), so scrolling through lists requires an awful lot of button pressing, especially as some of the pick-lists contain dozens of entries. A kind way to describe the programming interface is 'traditional'. A less kind way is 'tiresome and somewhat error prone'.

A much more productive method is to create your setups on a PC using the excellent Companion9X software, and transfer them to the transmitter via the USB cable. No cable is supplied, but most people will already have one (it has a standard USB connector at one end and a mini at the other).

Companion9X is a open source and closely tied to the OpenTx project. While it has some splendid features, including an invaluable 'test' mode, being able to edit setups on both the tx and a PC does introduce issues with housekeeping and syncing unless you exercise discipline.

One nice feature is that model setups may be backed up to a micro-SD card inside the transmitter.

Getting familiar

I spent a couple of hours familiarising myself with the hardware - charging the battery, calibrating the sticks, and playing with the X8R receiver. Binding is easy, and the servos were soon singing merrily. The transmitter comes with a simple model pre-cooked in the EEPROM.

Documentation and failsafe

The manual consists of 9 sides of A5. It covers the main hardware features, plus binding, fail safe, and range checking. However information about the internal charger is rather scant.

Receiver and telemetry

The supplied X8R receiver is a really neat little unit. It includes basic telemetry of signal strength and rx voltage. A low rx battery voltage warning is enabled by default on the transmitter.

Telemetry data is displayed on a dedicated page on the transmitter.

The X8R has a Smartport socket for connecting telemetry sensors. Unfortunately there's currently a dearth of compatible sensors. You can use non-Smartport sensors but it's messy, as it requires a hub and a bridge.

Batteries and charging

The Taranis incorporates a switching regulator which supports various battery types from 6-cell NiMH to 2S and 3S Lipo. The set comes with a 6-cell 800 mAh NiMH battery (it's not stated if it's a low self discharge type). This provides several hours operation.

The battery compartment was designed for AA's, and is too narrow for standard LiPo's. 2100 Eneloops fit perfectly and are the best upgrade option.

The transmitter incorporates an internal charger which takes its power from a mains adapter (included). The charger is compatible with NiMH chemistry only. No specification is provided, however it appears to be a 400mA delta peak device, which works out to a C/2 charge rate with the stock battery - just about right. (Personally I prefer to use an external charger as I like to be able to monitor the charge process. If you substitute LiPo's, then of course you must use an external charger.)

The transmitter lacks a power-on indicator, and it's quite easy to forget to turn it off. Fortunately you can configure an 'inactivity' alarm. I strongly recommend enabling this option. I would also like to have seen an automatic low voltage cut-off as well to avoid accidentally deep-discharging the battery.

The battery connects to the motherboard via a JST-XH connector: On my set, the connector is a slightly loose fit in the socket. No doubt FrSky chose JST-XH as it allows 2-S Lipos to connect via their balance plugs, nevertheless I would have preferred a better quality connector in such a critical area.

Transferring settings from Companion9X

Transferring model setups between the Taranis and Companion9X is easy - once you know how. I hadn't intended to go into too much technical detail, but this is one area which does warrant some explanation.

Key points to note:
  • To read/write model setups, make sure the transmitter is switched on and warnings cleared before connecting to the PC.
  • To read/flash the firmware, first install the Zadig driver. Make sure the transmitter is switched off  before connecting to the PC.

FrSky Taranis transmitter
Channel monitor showing F3F setup after uploading from Companion9X


My F3F setup uses 37 mixer lines and various custom functions. Nevertheless, the response using the X8R receiver is very good - visibly better than the equivalent setup on the Multiplex Profi 4000.


So... first impressions: conservatively styled, adequate mouldings, nice sticks, though average overall ergonomics. Documentation is poor. Poor access to on-off switch due to neckstrap balance arm. Latency with the X8R Rx seems very good. The native UI is rather dated and most pilots will want to program it using Companion9X. Battery connector could be better.

If all this sounds a bit niggly in part, remember that the distinguishing feature of this radio is its OpenTx operating system and its - OK, I'll say it - its startlingly low price.

I have already posted about OpenTx, but to quickly summarise: OpenTx is an extremely flexible o/s with support for sound, integrated telemetry and many other features you'd normally expect on much higher price sets. OpenTx does have a steep learning curve though. If you understand Multiplex's style of programming, you'll have a head start. If you have trouble understanding programming of radio gear in general, however, OpenTx is not for you.

What next? Well the Taranis now has my full-fat F3F program installed, so the next task is to evaluate the radio in the field. This really is the acid test - features are all very well, but ease of adjustment on the slope is crucial, especially when trimming a new model.

Stay tuned.



Anonymous said...

Driver install details can be found in the manual for opentx.

Unknown said...

Hi, I have just used my Taranis and so far it performs well. I have a couple of niggles: Poor standard Tx battery supplied and if replaced by a 2100 mAh NiMH, or Lithium pack external charging requires the battery cover to be removed each time charging takes place. These covers are not designed to be removed so often and will eventually break in the retaining lug area. The second niggle relates to the Failsafe mode. This only works with the X series receivers, so the old Frsky 8VR-11 receivers will not have the failsafe feature - I'm not happy about this so I guess the only option here would be to use the old Frsky JR type Tx module.