What I did with my Philco 39-116 was attach a Kraco FM converter to the AM
terminal running on a 12 volt power supply...tune radio to 1440kc and..voila!
One FM radio coming up.Now I can listen to all the old-time radio shows on our
FM stations Saturday and Sunday nights..It does not harm the Philco in any way. no modifications to it of any kind..more than one way to get FM on an older radio, and it sounds great!