My flight instructor told me they were taking the ADF system out of service, has anyone else here had to track one for their instructor or had to learn to use one?

Yes, it's no big deal. I'm not surprised they are dumping ADF. I started flying back when GPS was just getting underway so we still had lots of ADF around. I haven't been up in years though, so I'm not sure what its current status is. A big part of my instrument training was ADF and VOR approaches with a few ILS thrown in for fun.

Yeah, I've heard the same thing. It makes me wonder if its going to be U.S. wide, or just in the lower 48. Where I'm intending to fly (Northern Canada), the only thing to navigate off of (aside from GPS) is ADF. Makes you wonder though...