Many thanks to SWLing Post contributor, Jason Harvey, who writes:
Just thought I’d share, I’ve seen the bandaid dial scale mod for the D-220 to help with tuning. Not sure if anyone else has been able to mod the actual dial marker yet to make it more visible on the orange D-220 though, but it’s really not hard if you’re used to working on electronics. I just pulled the 2” plastic dial “string” out of mine after removing the back and lifting the circuit board, painted the front tab black, and reinstalled it in reverse. The end of the “string” has a tiny tab that just plugs into the front of the tuning pot cover, and when reseating the board it all slips back into place with a little guidance. This is made easier if you leave the tuning pot in the same spot it’s in when you lift the board, which one should note when they start.
[…] I came across this video that describes modding the XHDATA D-220 dial for better visibility.