[Elecraft] KX3 connection to doublet question

[stan levandowski]

For several years, I've been using my multiband non-resonant 94' 
doublet, fed with a short run of 450 ohm window line, to a remotely 
mounted SG234 autocoupler and then a 25 foot run of 50 ohm coax to my 
KX3.

Has been working with perfection; no complaints, except I cannot operate 
QRP below 3 watts because that's the minimum RF required for the 
autocoupler.


Now, if I wanted to extend my 450 ohm line and connect it directly to 
the KX3 and use the KX3's internal tuner, would there be any benefit in 
a 1:1 isolation balun at the KX3?


I can't think of any reason this would be necessary except as a 
transition from the window line to a convenient coax output to the KX3.


What would the KX3 prefer??


Thanks,
 Stan WB2LQF