[Elecraft] KAT100 tuning ability for bad antenna match

[barry]

I live in an upstairs flat (apartment in us!), and have a small loft
space about 23ft long at the ridge and about the same across. 

Would a KAT100 tuner be able to tune a random length dipole strung along
the ridge?

If not can you suggest an alternative antenna that would, I am seriously
limited in my options for aerials as you can see.

Any advice most welcome ... Barry G0MPA