I’m pleased to announce that a new version of CTR2-Mini called the CTR2-Mini+ is now available to order. This version has several enhancements over the basic CTR2-Mini that make it easier to build, more flexible, and depending on how you configure it, cheaper.

In case you’re wondering, the original Mini is still available.

Mini+ Features

The new Mini+ runs the same firmware as the Mini and has the following upgrades:

  • A built-in 12 VDC power supply allows you to power the Mini+ from your station power supply. You can also power the Mini+ using the USB-C connector on the front of the Wio Terminal, just like the Mini.
  • A built-in Radio I/O circuit allows you to control one radio without using an external Radio I/O module.
    • The RJ45 jack is optional. Install it if you want to use the Mini+ with the CTR2-Mini Radio I/O modules in case you have more than one radio you want to control
  • A built-in 6-button keypad is provided so you don’t need an external function keypad. Mini firmware v1.08 and above takes full advantage of the function keypad. Each button has two functions (normal and shift). Each switch on the Wio’s 5-way switch can also be programmed for two functions giving a total of 18 functions that you can access with one or two button clicks.
  • A new sidetone amplifier with a volume control and on/off switch has been added. The front firing speaker is louder and more usable for group code practice and the headphone jack is conveniently mounted on the front panel.
  • Several enclosure options to choose from:
    • Install it in a PacTec KEU-5 case as shown in the lead photo. This gives you a rugged professional looking controller suitable for a wide range of applications.
    • A custom acrylic wedge shaped enclosure similar to the Mini’s will be available.
    • The front panel can be mounted horizontally above the base PCB.
    • The front panel can be rack mounted or built into your own console with the base PCB attached to the back,

Front Panel

Mini+ Front Panel

Here’s the new face panel of the Mini+. The first thing you’ll notice is the board fits into the recess on the KEU-5 enclosure so it sits flush to the top of the panel. The controls are conveniently arranged and are more intuitive. The encoder has been was moved toward the middle so there’s no need for a left and right hand version. The retro speaker grill protects the speaker. The function buttons have their own area and are easy to reach. Colored pushbuttons can be used to make it easier to remember the functions assigned to each button.

Here’s a right side view of the Mini+. The display is way brighter than what the camera captures.

Mini+ Right Side View

Mini+ Left Side View

Here’s the rear view showing the 25mm standoffs that give the enclosure an additional tilt. 1/4″ thread protectors on the end of the standoffs provide rubber feet. The 10 degree tilt of the stock enclosure is not quite enough for my liking. You can screw on additional standoffs if you want even more tilt.


The Mini+ is easy to build with just two PCBs. The front panel PCB (on the left in the photo below) forms the face plate. Controls mount to the back of this PCB. The front side is silkscreened to provide a professional looking control panel. This board will take an hour or so to build. The dual-row 20-pin header that connects to the Wio Terminal’s GPIO bus is pre-installed. The bottom, or Base PCB (on the right) mounts in the bottom of the enclosure and connects to the face panel via a 16-pin ribbon cable. It takes around 20 minutes to build this board.

The PCB board kit comes with the hardware and rear panel insert to install the PCBs in the PacTec KEU-5 enclosure.

Controls connect to the front panel PCB using short jumper wires that are easy to install, and easy to remove if you need to replace anything. The photo below shows the pushbuttons and encoder wired to the PCB.

You’ll need to do a little drilling and grubbing to remove most of the recessed area on the enclosure. This work can be done using basic hand tools. I offer a pre-cut KEU-5 enclosure on the order form that has all the holes drilled and the recess area machined out if you don’t want to bother with preparing the enclosure.

Once the boards are assembled, mount them in the KEU-5 enclosure. The boards connect together using a short 16-conductor ribbon cable as shown in the photo below.

The rear panel is another PCB that only contains the cutouts and silkscreen labels for the jacks. It drops into a recess in the enclosure. The supplied 25mm extension legs can be added to the rear mounting screw locations to give the Mini+ more ’tilt’ for better visibility and control.

All in all you can plan on spending around 2 or 3 hours building the Mini+. The end result will be a great looking station accessory that you’ll be proud to show off.

Single or Multi-Radio Control

The Mini+ gives you the option of using the internal Radio I/O circuit to interface directly to one radio using the CAT I/O and PTT/K OUT jacks on the back of the unit. Just install jumpers on the internal radio I/O configuration header for the type of CAT interface your radio uses and plug your adapter cables directly into the Mini+, no external Radio I/O module required!.

If you have two or more radios to control, remove the jumpers on the internal Radio I/O configuration header and plug a CAT5 cable into the RADIO I/O jack for multi-radio control. In this mode the Mini+ works exactly like the Mini. A separate Radio I/O module is required for each radio you want to interface to.

Now the GOOD news…

The Mini+ is in production now! You can order just a PCB kit with mounting hardware and build it yourself, or you can order a fully assembled, programmed, and tested Mini+. If you want to build your own I have a BOM in the manual.

And even BETTER news!

I have found commercially available cables for the radio interface cables that up until now had to be custom built by each user. Commercial cables greatly simplifies connecting your Mini+ to your radio. Most of the cables can be purchased and used without modification. A few need to have plugs replaced with different plugs to fit your radio. You can order the cables directly from Amazon and do the modifications yourself or I can supply them already modified and tested. For more information and the part numbers for the cables for your radio visit the Radio Interface Cable page. Cables can be ordered on the order form when you order you Mini+.

Let me know if you have any questions about the new Mini+.

73, Lynn, KU7Q