Bob,

N9NEO {Bob} has the #43 Ferrite for building his own
Baluns so a 4:1, 9:1 or 16:1 should not be a problem.

4:1 (2T-to-1T) = 24 Turn Primary Antenna Windings
and 12 Turns Secondary Coax Cable Windings

9:1 (3T-to-1T) = 30 Turn Primary Antenna Windings
and 10 Turns Secondary Coax Cable Windings

16:1 (4T-to-1T) = 32 Turn Primary Antenna Windings
and 8 Turns Secondary Coax Cable Windings

The other Part of the T2FD is the Terminating Resistor
and an In-the-Attic T2FD Antenna may require some
Adjustment {Play-With} the Terminating Resistor to
get the Antenna to yeild the All-Band Coverage that
is sought from the T2FD Antenna.

more to think about - iane ~ RHF