It was originally designed as a "proximity loop". Set it on top of the R-8 and try it on MW just using the tuning capacitor until you can get it repaired, it should work.
I came very close to buying one of the originals at the estate sale of of a radio & t.v. station owner 25 plus years ago. That was before the patch cable days, they were pure proximity loops in those days. When I got back to where it was, it was gone.
You may find it hard to believe, but the guy had two mint T.V. studios in his basement, the huge 60's/early 70's studio cameras, the whole nine yards. I was stunned by the place. I must have walked around bug-eyed for a solid hour before I went upstairs.