An idea,
so if one took a random length say 30 foot length of twin feed,
stuck a big 50 ohm resistor on one end and a ballun to bring it to 50 ohm
resonance at the other,
in the tuner via coax. would it be 50 ohms wide banded because it sees the
50 ohm 'dummy load' at the far end as a match, and radiates a signal 'of
sorts' from the twin feed. If one used the tuner to miss match the
'antenna' The worse the match the more signal would squirt from the feeder.