Spektrum NX20 20-Channel DSMX Transmitter

An innovative connection to our RC aircraft

By Jay Smith | [email protected] Photos by the author

As seen in the February 2024 issue of Model Aviation.

HORIZON HOBBY AND SPEKTRUM RC released the first Android-powered transmitter, the iX12, in December 2017. In 2019, the company released the iX20, which was also powered by Android. That release led to some people requesting a similar release of a non-Android option with a high number of channels because the NX series peaked at 10 channels. Spektrum responded with the NX20, which provides many of the features found in the iX20, sans Android and at a lower price.

A case, short and long optional stick ends, USB magnetic adapter cable, orange grip set, and a NX20 decal sheet are all included with the radio.

Included in the box is everything that you need to be successful with your new transmitter, except for an AC adapter. A charge cable is provided but without the adapter to plug it into a wall outlet. Granted, most people probably have one or more with other devices; however, I want to keep one available in the transmitter case.

When supplying your own AC adapter, for optimum results, the manual recommends a USB power supply capable of at least a 2- to 3-amp output.

First Impressions

The NX20 transmitter will be familiar to those who have experience using the NX6, 8, 10, or the older DX line of transmitters. It feels slightly larger than those, but it is still comfortable to hold. The size difference is likely to accommodate the larger 5-inch 800 × 480 display screen.

The location of the memory card port has been moved to the back of the radio next to the USB-C port. I really appreciate that because the other NX radios had it on the bottom and I was concerned about dust or moisture getting in if the radio was placed on the ground.

Another appreciated update to the transmitter is the length of the antenna. It has been shortened so that when it is folded down, it no longer protrudes past the carry handle. This change does not impact the radio’s range and helps if you choose to lay your radio on its back because the radio sits on the carry handle and not the tip of the antenna.

The NX20 includes a magnetic USB cable and micro USB adapter for charging. This is nice because it will easily pull free if the cable is accidentally pulled or caught on something instead of the radio potentially falling.

Also included are additional orange transmitter grips and optional-use short and long stick ends. This provides a level of customization to have a radio that is most comfortable for you.

The NX20 is preloaded with model files for many Horizon Hobby BNF aircraft, saving you time if you fly those types of aircraft and like to use the setup files.

At a Glance

Specifications

Band: 2.4 GHz

Channels: 20

Flight modes: 10

Frame rate: 11 ms or 22 ms

Model memory: 250 internal

Modes: User-selectable modes 1 to 4

Modulation: DSMX/DSM2

Range: Full

Receiver: Not included

Resolution: 2048

SD card/AirWare capable: Yes

Telemetry: Yes

Transmitter battery type: Lithiumion; 10,500 mAh

Price: $1,299.99

Included

• Spektrum iX20 transmitter
• 10,500 mAh Li-Ion transmitter battery pack (installed)
• Custom carrying case
• Custom neck strap
• Short and long optional stick ends
• USB magnetic adapter cable
• Magnetic micro USB adapter
• Orange grip set
• NX20 decal sheet

Pluses

• 5-inch 800 × 480 color interface.
• Wi-Fi and USB connectivity.
• Good ergonomics.
• 250 model memory (internal).
• High-capacity transmitter battery.

Minuses

• Does not include an AC adapter.

Using the Transmitter

The built-in charger requires a USB power supply capable of at least 2- to 3-amp output. After connecting it to charge, I read the manual. A printed version is provided with the radio and a digital version is available online.

The NX20 uses Clear, Back, and Function buttons, as well as the scroll wheel, for programming and navigation. This should be familiar to anyone who has used an NX or DX radio in the past.

A closer look at the switches, trimmers, sliders, and knob on the left and right sides of the transmitter.

The next step was to register the transmitter, which then allowed for updates. I decided I would use the Wi-Fi option with the transmitter to register. Before trying that, I went to the Spektrum RC website just to confirm my login information. I ran into an issue logging in from the main page, so I reached out to Horizon Hobby support with a phone call.

A recording advised me that phone support was not an option and that I could email or chat with support on the company’s website. I took that route and my issue was resolved in a timely manner, but I am sorry to see that phone support is no longer available.

I was able to update the transmitter quickly and easily. A quick note about Wi-Fi: I leave it turned off and only turn it on if I want to check for updates. I haven’t found a reason to keep it on at all times.

If you are unfamiliar with the more recent Spektrum transmitters, the radio is turned on and off by pressing and holding the Spektrum bars logo below the nameplate for a few seconds. The transmitter is designed to prevent you from inadvertently powering it on by touching the power button. It boots up quickly and is ready for use.

All of the radio programming is done using the Clear, Back, and Function buttons on the left of the screen, as well as the scroll wheel situated to the right of the screen.

Behind the battery cover is a 10,500 mAh Li-Ion transmitter battery. The back of the transmitter provides access to the USB-C port, memory card port, wired trainer and CSRF port, and a headphone port.

Using the Wi-Fi option with the radio, you can register it, as well as download updates, without using a micro SD card or USB cable. The author is downloading the latest update.

This shows the Function screen.

Here is a quick overview from the manual regarding navigation.

The scroll wheel is used to move through the screen content or change programming values. Press the scroll wheel to make a selection. Use the Back button to go to the previous screen (for example, to go from the Mixing Screen to the Function List). Use the Clear button to return a selected value on a screen to the default setting.

Direct Model Access enables you to access the Model Select screen without powering off the transmitter. Anytime the transmitter power is on, press the Clear and Back buttons to access the Model Select screen.

I appreciate the quick access to the Model Select screen because it is one of the most commonly accessed screens when using the transmitter.

From the main screen, when you depress the scroll, it provides the Function List. This list is used to select and change details specific to your model’s setup, such as servo travel, reversing, mixing, etc.

One handy screen found in the Function List is the Charge Status. This provides the status of the battery, including the percentage of charge. When the transmitter is connected to a USB power supply, the page will also show the charge current and input voltage.

At the bottom of the Function List is System Setup. Enter the System Setup menu to define baseline settings for your model, such as the type of aircraft, wing type, flight mode setup, etc. The options chosen in the system menu configure the Function List for the chosen model number for your requirements. Some options, such as the flap menu, will not appear at all in the function list until they are selected within the System Setup menu.

When you access the System Setup menu, the radio-frequency functions of the transmitter will be disabled. It is not recommended to access this menu while an aircraft is being controlled by the transmitter.

The radio includes a balanced neck strap mount, as well as a neck strap. This is appreciated since that is my preferred way to hold my radio when flying.

The Hall-effect gimbals are smooth and their tension is easily adjustable from the front of the radio. Simply remove the screw covers. Using a small Phillips screwdriver, turn the appropriate screws near the sticks clockwise a small amount to tighten the stick tension and counterclockwise to loosen it. The manual provides the locations of the screws. You can also add or remove the rachet on the throttle stick the same way.

The back of the transmitter provides access to the USB-C port, memory card port, wired trainer and CSRF port, and a headphone port. The radio also includes M3-threaded mounting holes for a CSRF module, if you choose to add one.

Advanced Options

Because it a 20-channel radio, the NX20 has a few advanced features that I want to mention. Multiengine aircraft are cool, and the NX20 is ready to support them with Multi-Engine Control. In Acro mode, the Multi-Engine screen is available, allowing programming for up to four-engine aircraft. You can select any configuration of two, three, or four engines, allowing the engines to be independently controlled.

The System Setup menu is used to define baseline settings for your model, such as the type of aircraft, wing type, or flight mode setup that you are using.

The Charge Status provides the status of the battery, including the percentage of charge. When the transmitter is connected to a USB power supply, this page will also show the charge current and input voltage.

The NX20 includes programming for airplanes, sailplanes, helicopters, and multirotor models, with 14 programmable mixes and up to 10 different flight modes and eight sequencers.

The NX20’s telemetry system is compatible with all generations of Spektrum DSMX systems, including module-based receivers with integrated telemetry, and Smart technology.

Using the Sequencer on a Scale model frees the pilot to focus on flying while other actions are taking place, such as opening the gear doors, lowering the gear, and closing the doors. You can also control the speed at which these things happen. The Sequencer menu option provides this-then-that mixing with a time delay. Eight sequences are available to control two functions each (A and B) in two timing directions (forward or reverse). Sequences appear throughout function screens as assignable switches.

The switch setup on the NX20 allows for analog, digital, logical, and combo. Analog allows all sticks, knobs, and sliders to be used as a kick point to turn on functions such as mixes. A kick point is the position along the travel where the stick acts like a switch. Digital Switch Setup allows you to define the position values of each digital switch and flight mode switch.

Logical Switch Setup enables you to use two inputs to select as many as nine different switch positions. There are 16 logical switch setups available. When the table is set up and defined, you can select the logical switch positions anywhere in the programming menus where switch selections are available. Combo Switch Setup enables you to use two input devices to activate a switch, with an and/or option to tie the two input devices together.

Conclusion

The Spektrum NX20 is now the flagship offering in the NX line of radios and will be familiar to anyone who has experience with the lower channel-count offerings of the NX line and the DX series of transmitters.

Spektrum has continued to build upon its 2.4 GHz radios that date back to the DX6 that was released in 2005. Some of the features, such as Model Match, BNF models, aircraft setup files, and telemetry, seem commonplace now, but all have led to a more streamlined experience.

Those who are flying more complex aircraft will greatly benefit from the additional channels that the NX20 has to offer at a lower price tag than the iX20, as well as those who don’t want or need an Android operating system. If you are looking for additional information about the differences between the NX20 and the iX20, Steve Petrotto did an excellent video addressing that. A link is provided in the "Sources" section.

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