[Elecraft] Antenna Feedline Question

[Tom McCulloch]

Hi all,
  I am running a barefoot K2 with various options, including the auto-tuner 
and am getting ready to put up a new antenna.  I've decided on a 40 meter 
dipole that I will feed with 450 ohm 'window' line.  This will be my only 
antenna, at least for a while.  I operate mostly on 40 meters (CW) but also 
a bit on 20 (psk31) and 15/10 (also CW) when they are open and hope to tune 
the 40 meter dipole to those bands with the auto-tuner.

 I am planning to run the 'window' line all the way into the shack to the K2 
(which is about 5 or ten feet from the outside wall).  My question is should 
I also use the BL1 at the K2 and will I have any trouble tuning to the other 
bands.  I guess I don't understand what 4:1 means, in this case as I'll be 
using 450 ohm feedline to the K2.

Thanks in advance for your comments.

Tom
WB2QDG
K2 1103