Several CTR2-Mini kits are available as are complete plug & play units.

Regardless of the options you choose you will always need to provide the Wio Terminal and micro-SD card to complete the system. I don’t supply these because I would need to increase their cost to cover handling and shipping.


Many hams like to build things from scratch and have their own junk boxes full of parts they’re just aching to put to good use. For these hams, I offer a bare board kit. This kit includes the main, GPIO interconnect, encoder, and one radio I/O PCB. SMT devices are preinstalled as shown in the photo below. You can use the bill-of-material list to order parts to complete your kit. Order CTR2-Mini PCB on the order form for this kit.


Not everyone wants to go through the trouble of ordering parts to build a project. With the cost of shipping now days project costs can add up fast. For these people I offer a complete package of parts to build the circuit boards. The photo below shows what the completed boards will look like after you install the components. These kits include the pre-built 16-pin ribbon cable. You’ll need to provide an enclosure for the boards or order one of the enclosure kits below.

Select CTR2-Mini-KIT on the order form for the complete part kit.

I only supply encoders with knurled shafts (as opposed to flattened (“D”) style shafts. The knob for these encoders costs a little more because they use a set screw instead of a spring retainer but I feel like they’re a better choice for this application.


I can supply enclosure kits in either right or left-hand versions if you don’t want to create your own enclosure. The right-hand version, CTR-Mini-ENCLOSURE-R, has the encoder/speaker mounted to the right of the display as shown below whereas the left-hand version, CTR-Mini-ENCLOSURE-L, has the encoder/speaker mounted to the left of the display. Choose the one that best fits your operating style.

Right-hand enclosure kit
Left and Right-hand CTR2-Minis with user supplied Wio Terminals

All enclosure kits come complete the the following items:

  • 1 ea. Unassembled CNC cut acrylic snap-together stand
  • 2 ea. CNC cut Hammond 1551HBK enclosures – one for the encoder/speaker and one for the radio I/O
  • 4 ea. M3 screws, standoffs, and nuts for mounting the main board to the stand
  • 2 ea. M2-5mm machine screws to secure the Wio Terminal to the stand
  • 4 ea. tapered screws for the Hammond enclosures
  • 4 ea. silicon rubber feet
  • 1 ea. Black 1.3″ knob with finger hole for encoder

You may need to do a little clean up on the stand. Sand the nubs off the sides then use a small square file to remove the rounded inside-corners on each tab. The stand snaps together tightly but I suggest you add a drop of super-glue to the inside-corners of the tabs before final assembly. The resulting stand is pretty rugged when glued.

Select CTR2-Mini-ENCLOSURE-R or CTR2-Mini-ENCLOSURE-L on the order form for these kits.


For those that don’t enjoy building equipment, or simply can’t do it anymore, I offer a complete plug & play CTR2-Mini. These units come fully tested and assembled and include one radio I/O module. You only need to provide a Wio Terminal, a 4 to 16 GB micro-SD memory card, and a CAT5 cable for a complete system. There are two options to choose from depending on where you want the encoder mounted. You can add additional radio I/O modules to your order if you want to control multiple radios using a manual RJ45 switch. Radio I/O modules are available as kits or fully assembled units.

I can also supply units without a Radio I/O module for Flex radio users at a reduced cost. Just let me know on the order form if you don’t need the Radio I/O and I’ll adjust the price accordingly.

  • CTR2-Mini-ASSM-R comes with a right-hand mounted encoder (shown below)
  • CTR2-Mini-ASSM-L comes with a left-hand mounted encoder
Right-hand CTR2-Mini waiting for Wio Terminal installation

I custom build and test each assembled unit so it may take a little longer to ship than the parts kits.


For those wishing to add additional radios to their CTR2-Mini system I offer separate radio I/O modules. These modules can be purchased in kit form or as completely assembled units. The kit includes the PCB, all the parts required to complete the unit, and a CNC cut Hammond 1551HBK enclosure. The photo below shows an assembled radio I/O module awaiting final assembly.

To order the kit, order CTR2-Mini-IO. To order a completely assembled unit order CTR2-Mini-ASSMIO.

Just connect them to the Mini through a manual RJ45 switch. Just select a port on the switch and then select the same Radio Port in the Mini to connect to each radio as shown in the diagram below.

Using multiple radios with CTR2-Mini


For those that only want to use their Mini on a Flex 6000 series radio I can supply kits and assembled units without the Radio I/O module. Recent changes in the Mini’s firmware allows you to send both PTT and KEY commands to your radio over the WiFi connection so a physical Radio I/O module is not required. Just indicate on the order form if you want me to remove the Radio I/O module from your kit or assembled unit.

NOTE: I still have some Flex-only kits available. These kits don’t include the main board or speaker for the sidetone (no main board = no paddle input and no sidetone). These were intended for users that only wanted a physical tuning knob and memory management for their Flex radio. This unit supports WiFi PTT control but not WiFi KEY control (again, no paddle circuit). Contact me for the price of the Flex-only kit or assembled unit.

Since I’ve added the ability to control PTT and KEY inputs to the Flex radio over the WiFi connection you’ll need the main board and sidetone speaker so I am now offering to reduce the price of the kit or assembled unit by the cost of the Radio I/O module if you don’t want it included in your order.

If you ordered a Flex-only unit and would like to upgrade your unit to include the main board and sidetone speaker, contact me for the price of the upgrade kit.


By default, CTR2-Mini uses solid-state Key and PTT outputs to your radio. These work great for newer rigs but older tube rigs typically use negative polarity grid-block keying so these outputs don’t work so well. I offer a reed relay upgrade kit that includes two reed relays that offer dry-contacts and can switch 200 volts at 1/2 amp. Order CTR2-Mini-RELAY on the order form to order this upgrade.

If you need this option, make sure you order it when you order the radio I/O boards. I need to cut two jumpers and add SMT snubber diodes to the board. I’ll also solder in the relays even on the kit board.

You can use the CTR2-Mini Order Form to order the options you want or you can contact me directly if you have questions or other requirements.

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