Featured in the September 2015 issue of MAN, the new JR 28X from JR Americas is an amazing radio system.
I have been a JR radio enthusiast for many years and have always found the brand to be rock solid in the performance department. One of my first serious, “go to” radios was the touch screen equipped JR 10X. Eventually it was eclipsed by the pro level JR 12X. Recently, when JR Americas decided it was time to replace the 12X, the plan from the start was to create, from the ground up, a new system with quality and features to make it a true Flagship radio. Well, I was very impressed the first time I saw the 28X transmitter, and after using it for a while now, I can definitely say that it has indeed accomplished JR’s mission. Without exaggeration, the new JR 28X sets a very high standard for professional grade programmable radio systems. Let’s take a closer look and see what this amazing system beings to the party.
Located above the display, a total of 24 switches, give you wide open device assignment and location options. These include digital trims, rotary knobs, 2- and 3-position switches, and side mounted slider switches. The biggest and most obvious feature setting the 28X apart from the rest is its large colorful and easy to operate touch screen with clear icons and “swipe select” page displays. Also, the radio’s operating system is Android based so working around the menus is like adjusting a cell-phone or a tablet.
(Above) Standard Main Screen Display
The learning curve is similar to learning a new cell phone, at least it was for me. In the basic list of functions there is everything you would expect including dual processors for extremely smooth interfacing and ultra-reliable RF output. The user interface, (the main screen), is very customizable; you can even change wallpaper and color schemes to personalize your programming experience. Having an Android operating system also provides Wifi connection to the internet. This allows downloads of photos as well as control program data. In all, there is 4GB of internal memory and 512MB of RAM. The 28X also has an external SD card slot for additional memory storage space for models, images sound and telemetry data.
Looking at the 28X’s basic makeup, the transmitter is housed within a cast aluminum chassis and it comes with an integrated USB host controller and USB device port allowing easy data and PC interfacing and connection. Its stick units are supported by CNC aluminum ball-bearing supported gimbals and the stick step resolution is an amazing 65,536 steps which is 16 times more precise than other RC radio systems.
(Above) Precision Stick gimbals give a ultra-fine control feel.
(Above) look close. There’s something special about the control sticks
Unique to the 28X are small but very useful stick dials located midway up each of the control sticks. Two additional channels can be assigned to these for various functions. The transmitter comes configured with sixteen 14ms (14 microsecond refresh rate) channels. If you require more than that, you can add four (56ms) channels at a time, in place of one 14ms channel. So the final 28 channels are in a configuration of twelve 14ms channels and sixteen 56ms channels, all of which are proportional. For normal pilots, you won’t be able to feel the difference between the 14ms and 56ms channel performance. The transmitter uses the ultra-secure 2.4GHz DMSS (Dual Modulation Spectrum System) signal modulation which maintains high servo response speed and simultaneous telemetry functions.
There is a small compartment under a sliding cover that includes a USB and mini USB port, a microphone jack, a trainer connection and the charger port. The slot for the SD Card is on the right side of the transmitter also under a protective cover. The radio comes with a 3200mAh Li-Ion transmitter battery and the battery compartment is arranged to accept a second battery pack for greatly increased power duration.
Another unique feature with the 28X is the throttle stick travel adjustment. As well as being able to adjust the length and tension of the throttle stick, you can add the optional stroke adjustment blocks to the gimbal, to adjust the throttle travel. The same feature can also be used to adjust the elevator stick’s stroke if desired. The blocks provide angle reductions of -5, -10, -15 degrees, as well as an option for fixing the throttle stick in the neutral position with no movement. When using these limiter blocks, the control function does have to be recalibrated, (information for this is provided with the blocks).
(Above) my customized Main display setup with the wallpaper and widgets I use the most.
I really like the look and functionality of the main display, which in the instructions, is referred to as the Desktop. You set up the available screens by pressing various icons from the sub-menus and position them onto the main display. Four frequently used icons can be added to the Docking section to the right of the desktop. This Drag-n-Drop icon feature really speeds up your screen customization. Across the top of the screen is the model name, (at the top left), while smaller standard icons to the right show for the model type, wifi-connection, transmitter battery voltage (an optional second battery pack icon if installed), and local time.
All the icons are found on the Function, System, Other and Widgets screens brought up by pressing the Menu Icon. Then by pressing the icon it is activated so you can move it. Also, you can select various wallpapers by pressing the sub-menu button to the left of the screen while the main desktop is displayed.
For my radio setup I included one of the timers, the transmitter voltage and the receiver voltage icons as well as the six trim input indicators. In the Docking area I placed my Dual Rate, Servo Reverse, Servo Travel and Sub-Trim icons. On the secondary screen to the left of the main display I placed the icons for Binding, Model Type Select, Mixing, Differential and the Servo Monitor. There are three additional secondary screens available.
Fifteen flight modes (FM) are available for each of the aircraft type, (Acro/Heli/Sailplane), with each FM being completely customizable. When it comes to alerts, the audio controller makes it very easy to setup. You can use Voice, Vibe, Music and Audio alarms with what every setting you wish including Telemetry perimeters.
A very cool feature is that the Trim input switches can be used to adjust almost all of the mix curves and other functions during flight. The entire curve can be increased and/or decreased using the trim input switch while the curve shape does not change, or alternatively individual points on a curve can be adjusted during flight.
On top of all these basic must-have features, the 28X also brings some new special features to the game. These include:
Channel Sequencing: (referred to as Gear Function). This handy function was introduced after many JR customers, especially RC jet and scale guys, continued to ask for it. It allows you to setup custom servo/control sequences with the flip of a switch. Basically it simplifies setting up the movement and combination of the retractable landing gear and timing it with the movement of landing gear doors in both directions of landing gear travel.
Voice Alerts: The voice is adjustable and you can adjust the priority orders for when the radio calls off the stats. You can also assign the function to a switch so you can turn the voice on and off during flight.
Cool Trick: If you plug in a wireless mouse adapter to the 28X’s USB port, you can actually use a wireless mouse to help navigate and adjust the programming menus. This makes bench setup faster and easier, especially if you have dried glue on your finger tips!
(Above) The 7-channel RG712BX antenna diversity receiver.
Included with the JR 28X is the 7-channel RG712BX antenna diversity receiver. It has seven servo outputs and an XBus port to allow expansion to utilize all the channels and features of this transmitter.
The optional XBus system capability employs serial data transmission instead of PWM (Pulse width modulation) signal control which is usually used to control RC aircraft. The XBus signals contain all channels. Each device selects data that is assigned to it and they respond according to the data. Before connecting the XBus products, continue with the normal channel assignment using the transmitter or other devices. If this is not done first the devices will not respond to the signals. Do not directly connect conventional PWM devices to the XBus output. Doing so can cause damage. The power supply can be separated for each device using the optional JR XBus “Hub”.
New radios come to market every day but a game changer like the JR 28X is a generational addition. It totally redefines programming in the JR Americas line and in my opinion, will remain their flagship system for a long time to come. It has become my new Go To radio and I plan to put it to good use. If you are looking for a truly unique pro-level radio, look no further, the 28X is here to stay.
Transmitter: JR 28X
Distributor: JR Americas (JRAmericas.com)
Type: 28 channel computer mixing
Radio Frequency: 2.4GHz
Modulation: DMSS (Dual Modulation Spectrum System) FHSS Spread Spectrum Method
Power source: 7.2V 3200mAh Li-Ion battery (option for 2)
Neutral position: 1.5ms
• Integrated Full Color touch screen with Android interface
• Advanced drag-n-drop screen graphic icons
• Dual Stick Aux. control levers
• 15 flight modes for Acro, Heli and Sailplane menus
• Curve adjustment by Trim device
• Audio Controller for voice, music, and telemetry notifications
Other Useful Screen Displays
(Above) Customizable Model Name/Select screen with digital image.
(Above) Additonal auxiliary screen on either side of the main screen, just a finger swipe away, you can add whatever additional function icons to these pages.
(Above) Well thought out management for servo control throws.
(Above) Function Menu with clear icons for selecting and adjusting what you want
X-Bus servo control setup could not be any easier with the available screens.
What’s the maximum time you can program a sequence for? I’ve heard you can only set a maximum of 10 which is pretty much useless when used with the latest electric retract systems from Robart for example as a full sequence can take almost 30 seconds in one direction.
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