The original CTR2-Mini appeared in the September 2022 issue of QST. The Mini has since been upgraded to the Mini+ in order to provide additional functionality at a cheaper cost.

This information has been archived and presented here for your reference. If you would like to purchase the PCB kit or an assembled original CTR2-Mini, please contact me for discounted pricing.


The PCB kit for the original Mini includes PCBs for the Main, GPIO interconnect, Encoder, and one Radio I/O module. SMT devices are preinstalled as shown in the photo below. Use the Mouser BOM project link below to order the through-hole parts and Wio Terminal to complete your kit.

NOTE: The original CTR2-Mini-PCB-Kit is still available if you prefer this version. I just took it off the order form to simplify things. If you prefer this version over the Mini+ contact me for special discount pricing.

CTR2-Mini Remote Function Keypad PCB

For those that have, or want to build a CTR2-Mini but want a function button keypad to use with the latest firmware update, I can provide an inexpensive function button PCB. This keypad installs in a Hammond 1551 box (the same box used for the Radio I/O module) and plugs into the Remote PTT jack on the Mini using a standard mono or stereo 3.5mm cable. Information on this option can be found here.

CTR2-Mini Remote Function Keypad

Mouser BOMs

I do not supply the through-hole part required to build the Mini. Instead, I have created custom Mouser BOMs (bill of material) that you can use to easily order the necessary through-hole components to complete the PCB kit above. You can order directly from Mouser or use the BOMs to order the parts from your favorite supplier. You can find the BOMs and schematics here.

Enclosure Options

For the Mini I can supply fully assembled enclosures for either right-hand or left-hand mounted encoders, or for two Minis mounted in the same 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.

Enclosures come with the base pre-assembled as shown below, one Encoder/Speaker and one Radio I/O enclosure, two 2mm screws to mount the Wio Terminal to the base and mounting hardware to mount the Main PCB. A 1.3″ knob is provided for the encoder. Silicone rubber feet are included.

Right-hand enclosure kit
Left and Right-hand CTR2-Minis

Single Mini enclosures come with the following items:

  • 1 ea. Assembled CNC cut acrylic 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 dimple

A Dual-Mini enclosure is also available. It can hold two Mini boards, two Wio Terminals and two encoders and speakers. This is an ideal solution if you want to run two Minis to control different slices on your Flex radio or both VFOs on your FTdx101. It also makes a pretty compact SO2R interface when used with the CTR2-Mini SO2R Controller. This option is also available as a completely assembled and tested.

The Dual Mini enclosure comes with the following:

1 ea. Assembled CNC cut acrylic dual Mini stand
4 ea. CNC cut Hammond 1551HBK enclosures – one for each encoder/speaker and one for each radio I/O
8 ea. M3 screws, standoffs, and nuts to mount the main boards to the stand
4 ea. M2-5mm machine screws to secure the Wio Terminals to the stand
8 ea. tapered screws for the Hammond enclosures
6 ea. silicon rubber feet
2 ea. Black 1.3″ knobs for the encoders

Assembled Dual Mini

I have a limited number of PCB kits and assembled enclosures for the original Mini available. Contact me for discount pricing if you interested in building this unit.