The Spektrum DX18 is capable of transmitting on 18 channels proportionally and will competently fulfill the demanding requirements even of the most challenging aircraft. Supplied with an AR9020 X-Plus capable nine channel receiver, expansion is easily achieved with the addition of and X-Plus expansion module(SPMXP8000). Just plug the module into the AR9020 and bind it. The DX18 will automatically detect the extra channels and give the menu options needed to assign the extra functions. It's just what anyone who flies complex scale models or high-performance sailplanes needs.
Advanced Ergonomics are the key to a well-balanced radio; one that is comfortable in the pilot's hands with easy to reach sticks and all of the switches and knobs. The large backlit LCD display ensures setting up all of the multiple channels and assigning all of the controls is easy on the eye and Spektrum's AirWare™ software has all of the programming functions a pilot could want. The intuitive SimpleScroll™ interface makes navigating menus and changing settings as simple as "roll and click". It's almost like using a mouse.
It's easy to always be up to date with the latest version of Spektrum AirWare thanks to the Spektrum Community and the Spektrum Data Interface (SDI). Registering the DX18 at community.spektrumrc.com will see users receive alerts whenever a new version of Spektrum AirWare is available. They can then download the new version onto a standard SD card and upload it to the transmitter via the SDI. The SDI can also be used to upload setups for specific models from the Spektrum Community site, share model setups with other DX18 owners or store extra model memory. An SD card is included advantage can be taken of this handy feature right away.
The DX18 is equipped with a built-in telemetry feature that delivers real-time information on things like the model's battery voltage, signal quality, engine or motor temperature, airspeed, altitude and more. And it all appears right on the big LCD screen so can be easily seen at a glance.
Special DX18 Features
New with the Spektrum DX18 is Absolute Servo travel definition that limits the travel to a programmed limited value even if the total values of the mix would create a longer throw.
Ten flight modes are available in glider mode, which covers all required parameters. The innovative Flight mode matrix gives perfect assistance for fast and safe programming.
A programmable time shift in the integrated sequencer of the DX18 activates mix functions. That enables two functions, for example Gear and Gear doors, to one programmable function.
Side rotary knobs
18 Channel with X plus
Mode 1 -4
Twin antennas, one fixed and a second antenna in handle
50 internal Model memory plus nearly unlimited Model memory storage capacity on SD Card
Large backlit 192x96 LCD Display
AirWare™ Software with heli, aircraft and glider modules
10 Wing type configurations
6 Swashplate types
2 Motor glider configurations
Free assignable channels
Free assignable switches
LiPo battery and integrated global charger
Up to 10 individually customised flight modes
Individual Flight mode names
Flight mode priority switch
Absolute Servo travel definition
Balance Function with 7 point curve for all servo channels
Sequencer for servo mixes with time shift
Telemetry with Flight log
12 programmable Mixes
Spread Spectrum technology uses different digital formats to transmit and receive radio signals on the 2.4GHz band. The band actually spans from 2.400 to 2.4835 making eighty channels available with a band width of around 1 MHz. it has been I use for some time by government agencies all over the word and has proven over time to be very, very reliable. It is also controlled by a set of rules agreed to by agencies and governments all over the world.
DX7 features DSM2™, which is second generation DSM. DSM2 provides all the benefits of DSM but with the added bonus of doing it faster. By processing the signal faster than any PCM radio system available today and at 1024 bit resolution the link that connects pilot and plane is sharpened making him feel more in contact and control of his plane.
This is a system of transmitting a radio signal to a receiver where rather than being fixed onto one channel it hops from one channel to another constantly, using a random sequence. In short the transmitter sends a stream of control data at the end of which there is a code that tells the receiver which frequency to hop to next. It does this hundreds of times a second and so the chances of any type of interference are virtually nil; if two devices did end up during their sequences on the same frequency at one time it would only be for milliseconds so you simply wouldn’t detect it. Unfortunately there are two big drawbacks for FHSS with regard to using it for models. Firstly the latency (response time). Ideally we want it to be zero but practically it tends to be around five milliseconds for most conventional radio systems. Some a quicker, some slower but FHSS at best has proven to be around twenty five milliseconds but more generally around fifty. Secondly is its response to interference. Should there be a break in signal it can take from two to four seconds for the transmitter and receiver to resynchronise and this clearly when controlling a plane, helicopter or car travelling at speed is unacceptable.
This is the system used buy Spektrum® (with a K). DSSS is unlike any other system we have had before in that it is aware of what is going on around it. When turned on a transmitter scans to find one of the eighty channels that is not being used, locks on and occupies it and then starts to transmit it’s GUID code. While this has been happening the receiver had been scanning the bands also looking for it’s transmitter GUID. When it detects it the two lock together to form a solid RF link. Once functioning the data transmitted is actually spread across the complete bandwidth using a random noise code which has the effect of digitally increasing the range of the equipment. The receiver is aware of its transmitters spreading code and can distinguish its intended signal.
A unique code that is programmed into every Spektrum transmitter. During the binding process the receiver assimilates the code and from that point in time will only respond to that transmitter. There is no limit to the number of receivers that can be bound to one transmitter so it can be used for several models. The GUID remains with that receiver until it is bound to a different GUID (transmitter). The GUID is actually a multi-digit code that makes possible 4.2 billion different individual ID’s so it’s going to be a while before they all get allocated.
The process whereby a receiver assimilated the GUID code of a transmitter. Once done the code remains with the receiver until it is bound with another transmitter. Once a receiver is bound to a transmitter there is no need to at any point re-bind it unless new failsafe settings need to be adopted.
SmartSafe deals subtly differently with two differing safety critical scenarios, one of which is especially important for electric powered planes. Fail-safe settings are established during the binding process at the positions of the sticks, usually low throttle and neutral on other channels.The first scenario is that the receiver is turned on without a signal from the transmitter. In this event all of the channels go to the fail-safe positions set during the binding process but receiver doesn’t send any signals out on the throttle channel, so the speed controller cannot arm and start the motor.Once the transmitter is turned on and an RF link is established the receiver will send out a low throttle signal and arm the speed controller once the stick is positioned at low throttle. From that point it functions, as do the other channels, as normal.
The second case scenario is that the signal is lost whilst both transmitter and receiver have an established RF link. In this event, as unlikely as it is, SmartSafe will take the throttle channel to its setting programmed during the binding process, while all other channels stay at last position held.
With a surface radio system the vehicles, be it cars or boats, move in two dimensions, the third one being the fixed surface they are moving on. Because of this their aerials are for the most part pointing upwards so that orientation to the transmitter remains constant. Planes are different in that they manoeuvre in three dimensions and as such are prone to what is called ‘fade’. This has the effect of momentarily reducing the output of the transmitter, which can obviously have disastrous consequences. Obviously it depends of the orientation of the receivers aerial too but it can usually be provoked by pointing the aerial of a transmitter directly at the model.
When a plane flies and performs aerobatic manoeuvres its aerial’s orientation to the transmitter is constantly changing and because of this it can at any time find itself in a sub-optimal position and subject to fade.
Spektrum radios feature DualLink, a system that is specifically designed to resolve this problem. Every DualLink receiver is in actual fact two receivers, each with its own aerial, the two of which are oriented at ninety degrees to each other. When the transmitter if turned on it scans for and occupies two free channels and then starts to transmit the same data simultaneously on both. Because there are two paths (the term for the relationship of the position of the transmitting aerial relative to the receiving aerial) should one be lost due the other will continue to supply the signal.
A new feature on DX7 that re-sequences the bits of data based on the type of mixing selected. So if dual elevators or 3-serco CCPM has been set-up ServoSync will see to it that those servos are performance optimised by receiving their impulses together. This results in a more positive feel to control input. Not featured in DX6.
It’s not uncommon to forget to check that the model that is about to take off is the one that’s profiled in the transmitter display. The consequences can be disastrous though. Once again Spektrum redefines flight safety with ModelMatch by making this kind of error a thing of the past. With DX7 a profile code is embedded into the receiver and if it doesn’t match the one embedded in the signal, indicated by the model name on the display, the model’s controls simply won’t respond. Not featured in DX6.