What Mod Is This?

Hi, I just received a PRO-2006 from eBay and after replacing the backlight (about the only mod I know how to perform) I noticed another modification had been done at some point in this radio's life. The seller either knew about it and had a good reason not to mention, or simply had no idea. Maybe an estate sale buy...

At any rate, from the pics provided, can anyone tell me what this mod is meant to do?

Thanks,
Dominic

Discriminator tap.

Discriminator Output PRO-2006 / COM-205

nevermind