[Elecraft] High SWR below 40 meters

[Jan Ditzian]

My K3 has been having RF feedback problems with an 80 meter antenna.  In 
order to resolve things, I built an 80-meter dipole to use as a test 
antenna.  While all this was happening, over the past few months, I also 
added a used KAT-3 tuner and a KXYN3A to replace the original synthesizer.

After building the dipole, I was puzzled that it would not tune up on 
80.  I do not know why it took me a week, but I finally checked out the 
rig on my dummy load.  It shows a high SWR on the dummy for all 
wavelengths greater than the 40-meter band--60, 80, and 160. The rig 
works just fine on 14 mHz. and up, and I can certainly tune it up on 40 
meters.  Further checking shows that there is no output on 60-160, 
whether using the Tune mode at 5 watts or CW mode at 70 watts.

I have no idea when or why this happened, but I really need to know the 
how it happened, so I can fix it.  Can someone give me some guidance on 
what to look at to figure this out?  It is possible that resolving this 
problem will also result in a resolution of the RF feedback problem, 
although I won't count on that.

73,

Jan, KX2A