I use the K3 internal tuner then to a BL2. Most bands are good with the 1:1 ratio. That little switch is handy to go to 4:1 for some bands.
I have a 85 m loop and have worked 160 to 6 meters with good results.
On 160 I do have to tie the 450 Ohm line wires together and feed it against ground. A DPDT knife switch does that for me.
73, Ty, W1TF, K3 #696