Wayne
Doing Plenty, Kinda Slow
The matter could be clearer-than-currently-stated in the rules. but maybe think of it this way instead:Color me dense but doesn't the unit(s) the DC is being placed on have to lose ? in order to fire on the placing unit? The placing unit would then need to survive all Dfire before the unit DC is "operable placed". At this point the defending unit is unconcealed and, therefore, not subject to Area Fire. If the fire came from other than the location the DC is being placed on, that's a different story.
You're Placing a DC (vs a Concealed unit).
When you announce "Place DC - x MFs" -- the "vs Concealed" is implied.
Opponent responds w/D1F, including w/the target unit, say -- and that shot costs that DC-targeted unit its Concealment.
Re that/all D1F vs the Placement MFs, your placing unit survives unbroken/unpinned -- thus, the DC is now "operably Placed," but "vs Concealed" is still implied, because that was the target state when you announced "Place DC - x MFs"
In summary,
o you Declare vs Concealed, inviting D1F;
o there is none of affect;
o [your DC is now deemed operably Placed vs Concealed;]
o in your AFPh, aside from possible malf, your DC auto-Detonates vs Concealed -- not matter the target's Concealment state at that time.
Hope that helps.