Hi Tim and thank you for the quick reply. I have recently returned to amateur radio after a 20+ year break so have some catching up to do, please me patient 
Hope the following makes sense. For portable operation I would like to use the 88ft doublet with a 300ohm ladderline feeder. On the radio end of the ladderline I was planning on putting a 1:1 current balun which is 2x12 turns of 18awg wire on a type 43 ferrite as per this link…
This takes me from the balanced feeder to the coax to the radio.
What I am confused about is, is this enough or do I need something else on the coaxial side of the balun towards the x6100.
The other question would be if I use a different antenna such as a G5RV would that be a better if less efficient option for an antenna?
Best Regards,
Paul G4HLF