Monday, March 16, 2015

Ladder Line and Loop

Finished install of 9 foot high NVIS 40 meter Horizontal Loop antenna.  Fed with 125 feet of Window line.  Window like e was run on ground and behind metal shed.  Syste. Was resonate at around 6.7 or so. SWR at rig was abt 1:1.5 at 7.0. 15 and 6 meters would not tune but 20 and 10 would. 
Today I cut feed line by abt 35 feet.  Now 20 and 10 tune  But not 40 and 15.  I am thinking kind g that impedence at 40 and 15 is too high due to either 4th and 3rd harmonic at 15 and 40 respectively.  Will add on more window line to test that feed line length is the problem.

Great NVIS article