Picked up this rig from a fellow on eBay and it had a Drake mic with keypad.  Doesn't seem to activate the DTMF feature, or maybe I am doing something wrong.

There is a DIN jumper plug to install on the rear panel that is supposed to enable the DTMF pad on the mic - at least that is what it appears to do, based on the manual.

The seller never used this feature, so he can't help me figure this out.

Anyone have some suggestions, or run into something similar?