The Lucky Strike, my M20C, is equipped with a KX155 with glideslope and a King NDB, in addition to a VFR GPS com. It also has an old KN86 ADF that is inoperable. I plan on using it as an IFR trainer in the Spring (it will also be my IFR traveling machine). I'd like an IFR GPS, but between the box and the installation it just isn't in the cards right now. On the other hand I could replace the inoperable ADF with one that works without spending big money. Should I?