Installation instructions for the CTCSS Board How to add CTCSS in SR-94HPC 1. Remove R254/R255 as show in the photo： 2. Remove this 2 screws but keep them for next steps 3. Install 2 copper pillar： 4. Insert the CTCSS Plug 5. Screw into the copper pillar： Have more questions? Submit a request 0 Comments Article is closed for comments.