CTR2-Flex Firmware Manual – v2.05.01b

May 25, 2026

• Added a note about turning the CTR2 keyer type to OFF so you can use the radio’s internal keyer.

There is a separate manual for CTR2-Dial firmware. You can download it here.

• Starting with v2.04.00 I’ve split the hardware descriptions out into three separate manuals:
  • CTR2-Uno
  • CTR2-Duo
  • CTR2-Quad
  • You can use the hardware manual for CTR2-Uno and CTR2-Duo for the older single and dual-knob CTR2-Dial and CTR2-Flex hardware.
• You can download the CTR2-Flex/CTR2-Dial firmware here.