No matter how I fooled with the DC jack legs I couldn't get it to stay put while I attached the nut.
Set it in the hole, tightened the nut, jack comes loose.
Set it in the hole with the legs spread out, tightened the nut, jack came loose.

Clipped a hemostat to one leg from underneath, tightened the nut, %#@&! jack came out.
Finally, I laid a straight edge across the switches and gauged the height of the jack from that and soldered it in place. aa