I think I know the answer to this and I could just try it and find out
on my own- but this is easier and funner to ask you guys. ;-) If I
were sitting out in my yard in the general vicinity of my Alpha Delta
DX sloper and had for sake of discussion my DX398 could I drop my
little coil (coupler) over my whip antenna and clip say a 10 ft. lead
directly to any part of the sloper? Would I receive the full benefit
of the sloper this way?

Just thought about that the other day. Curious minds want to know.
TIA