Mountain Man:
The drill cycle G83 is for deep holes, with full retract each peck. G73 cycle is for a short retract to break the chip, but not a full retract. Perhaps you have given the parameters the wrong values. Check the use of the R,L,Q parameters in the G-code description list. The "Q" parameter is a "delta" increment along the Z axis, according to my G-code list.
Personally, the descriptions in the listing could have been done better, such as showing a list of the R,L,Q parameters for drilling type, with an example. There are better descriptions than what is in the Mach3 listing.
John