[Elecraft] Antenna question

[Tom McCulloch]

Hi all,
  I'm considering putting up a 40 meter dipole fed with a 450 ladder line. 
I have a K2 which I run at about 5 to watts (I do not have the 100 watt 
amp).  The K2 also has the internal ATU.

  I have always used 50 ohm coax up until now.  Is there anything I should 
know about using the K2 with 450 ohm feedline?  (Will I need a balun, or can 
I just feed the ladderline directly to the K2's ATU and that will take care 
of the match.

Thanks for your help.

Tom, WB2QDG

K2 1103