Spektrum DX7 vs. DX6i

"While the Spektrum DX7 is the cream of the crop,
the DX6i may be all you need!"

Having found this page, you're more than likely familiar with Spektrum RC radio systems. Chances are you are doing some research to determine if the advantages of choosing a Spektrum DX7 over a DX6i justifies the price difference. I'm sure you don't want to waste money for features you will never use, at the same time you don't want to buy a radio that you will soon outgrow. I will point out the differences between the two systems so you can make an educated decision.

You will also find a table summarizing the major differences between the Spektrum DX7 and DX6i radio systems.

Programming Differences Between Spektrum DX7 and DX6i

The programming capabilities are what really set Spektrum's DX7 apart from the DX6i. While the DX7 allows airplane pilots much more flexibility for mixing channels for complicated setups, the advantages of the DX7 over the DX6i are much more profound for heli pilots. The following are the major differences between the two radios and should not be mistaken for a complete list of features.


Complete details of the Spektrum DX6i	Complete details of the Spektrum DX7

Model Memory

The DX7 allows you to store up to 20 different model airplanes or helis, where as the DX6i has only a 10 model memory. Both systems allow up to 8 characters for naming each of your models.

Training Mode

The Spektrum DX7 has 3 different training modes which are Normal, P-link and Slave/P-link where as the DX6i only has normal.

In normal mode the master TX must have the same reverse, travel adjust, dual rates, mixes, sub trims, etc. as the master transmitter.

In P-link mode the master TX maintains control over all of the programming such as reverse, travel, dual rates etc. and gives only the control over the stick movements to the slave TX. P-link/Slave mode is the mode that the slave must be in when the master TX is in P-link mode. Even though there are 3 different settings available, there are really only 2 modes of training. P-link and Normal

If you're considering buying the DX7 you're probably not a new pilot that needs training anyway. But this is a difference between the two transmitters that's worth noting.

Flap Mixing

Flap mixing allows you to set the elevator and flaps to a predetermined positions for taking off and landing. The DX7 allows for three different such settings, one for normal flying, one for landing, and another setting in between. The DX6 only allows for two settings which are normal flying and landing.

Airplane Mixes

Both the DX6i and DX7 are pre-programmed for three common wing types which are your normal wings, flaperon wings, and delta. Both the Spektrum DX7 and DX6i also have a preprogrammed v-tail mix

The airplane version of the DX7 allows for up to 6 programmable mixes where as the DX6i only gives you two. It's important to note that only 2 of the DX7 mixes allow trim settings to be used on the slave channels. Both of the programmable mixes of the DX6i have the option of allowing the master trim settings to affect the slave's trim settings.

Heli Mixes

The Spektrum DX7 offers more cyclic/collective pitch mixing (CCPM) capabilities than the DX6i. The DX6i will operate 1 servo/90 and 2 servo/120 type swash plates. The DX7 will operate 2 servo/180, 3 servo/120, and 3 servo/90 type swash pates.

The DX7 allows you to program 3 throttle curves and 3 collective pitch curves, where as the DX6i has only 2 throttle curves and 3 collective pitch curves. Each throttle and pitch curves for both transmitters have 5 programmable points.

The heli version of the DX7 allows for up to 3 programmable mixes and the DX6i only gives you 2 programmable mixes. If you're new to helis and need some more explanation of these features, I strongly suggest checking out this excellent RC helicopter website!

Summary of Programming Differences

I find it helpful to construct a table summarizing the differences between two products when making a big decision. So hopefully the chart below will help you feel more comfortable about your choice. Keep in mind that this table only points out the major differences between the two transmitters and aren't necessarily the only differences.

Features	Spektrum DX6i	Spektrum DX7
Channels	6	7
Model Memory (8 characters each)	10	20
Trainer Modes	1	3
Airplane Flap Mixing Positions	2	3
Airplane Programmable Mixes	2	6
Heli Swash Plate Types	1 servo/90 CCPM 3 Servo/120 CCPM	2 Servo/180 CCPM 3 Servo/120 CCPM 3 Servo/90 CCPM
Heli Throttle Curve (each 5 points/curve)	2	3
Heli Pitch Curves (each 5 points/curve)	3	4
Heli Programmable Mixes	2	3

Battery Differences

Another notable difference between the DX7 and the DX6i transmitters is the battery packs. The DX7 uses a typical 1500mah NiMH transmitter battery pack. The DX7 uses 4 "AA" NiMH batteries. Both come with appropriate chargers.

This doesn't seem like such a huge deal to me, but it is definitely something you should be aware of. Some people feel that using "AA" instead of a 4-cell pack makes the DX6i feel cheap and toy-like. I personally think it's an advantage because you can always throw in 4 standard "AA" batteries should you forget to charge the night before.

A typical 1500mAh transmitter battery should give you around 6 hours of flight time before having to recharge. That's a lot of flying!

Servos and Receivers

Spektrum's DX7 transmitter comes with digital servos which means you are definitely getting your money's worth with this system. Have you priced digital servos lately?

There is a hi-torque version and microlight version of both airplane and helicopter DX7 transmitters. Yes, there are two version of the DX7. One for airplanes and one for helis. It's the same radio with the switches in slightly different positions. The throttle comes unratcheted with the heli version, but includes the ratchet should you want to install it.

The hi-torque versions of both comes with (4) JR DS821 Digital High Torque Servos with Spektrum's AR7000 receiver suitable for glow powered planes. The microlight versions comes with (3) JR S285 sub-micro digital servos and a Spektrum AR6100 receiver. Only three servos are needed because small electric powered planes or helis use an ESC instead of a servos for throttle control. Details of each system can be found by following the links below.

High Torque Full Range Airplane Version

High Torque Full Range Helicopter Version

MicroLite Short Range Airplane Version

MicroLite Short Range Helicopter Version

You can buy the DX6i transmitter either with or without an AR6200 DSM2 6-channel receiver, but the DX6i is not available with servos as a package. You have to purchase the servos separately.

Spektrum Features common to DX7 and DX6i

Now that you're familiar with the differences between the Spektrum DX7 and DX6i systems, I'd like to highlight some of the Spektrum features that are common to both radios.

DSM2 Technology

Both the Spektrum DX6i and DX7 are full range transmitters utilizing Spektrum's DSM2 technology. This means that you can fly any size airplane or heli. You can even use the AR6000 DSM parkflyer receiver with these radios. Here are more details on the difference between Spektrum DSM vs DSM2 technology.

Model Match™

If you take off with your aileron or elevator servos working backwards, your RC plane is toast! Unfortunately many of us have watched very talented pilots nose plant their pride and joy because they selected the wrong model. Sure makes for a bad day at the field, that's for sure!

We're all human. If you fly multiple planes, chances are you will one day forget to switch models on your transmitter. In fact, this is such a widespread problem that Spektrum decided to put a stop to it with its Model Match Feature.

Spektrum's Model Match™ assures that this will never happen by mating each model stored in your transmitter with the specific transmitter installed in your RC airplane. If you select the wrong model, the receiver in your airplane will simply ignore the transmitter preventing you from even taking off. As you might imagine, there is a very good chance that this feature alone could end up paying for the entire radio system!

ServoSync™

Many larger size RC airplanes have redundant servos on control surfaces such as elevator or ailerons. The pulses from a conventional receiver get to the second servo a split second after the first servo. Spektrum's patent pending ServoSync™ allows these servos to receive their pulses simultaneously eliminating any binding or lag between the two servos. This subtle enhancement makes a huge difference to the response of the aircraft allowing you to feel more "connected" with your RC airplane.

ServoMonitor™

The Servo monitor feature common to both Spektrum DX7 and DX6i displays a graphical representation of each servo's movement in real-time. This is very handy when programming mixes on a new plane set-up as you can actually confirm that everything is programmed to move correctly without even switching on the airplane.