[Elecraft] 80m KPA1500 High reflected power problems

[Peter Dougherty]

John, I know there were some issues with my old tube amp, but it did load
enough to get me 275-odd DXCC entities with 1500W on 80 CW. The KPA has
never been used in the past on 80 since I was having antenna trouble (one
end was down all winter and it just got fixed today).

Everything's snow covered out the back so I don't want to play around at the
coax switch at the moment. I'll try bypassing the switch when it's a bit
warmer and the snow is gone.

Of note, last year with the weird SWR, the "old antenna" (same physical
space and height, just all different materials) was cut to 3750 and I used a
tuner for the bottom end. I found the tuner kept giving me "unable to find a
match" when I tried tuning with high power from my tube amp. I figured
replacing every factor in that chain would fix the issue; the only thing
that's the same is the antenna switch and the physical orientation of the
wires themselves. New amp, new coax, new balun, new wire, insulators and
even the support ropes were changed out.

 - pjd

-----Original Message-----
From: john at kk9a.com <john at kk9a.com> 
Sent: Saturday, March 9, 2019 4:55 PM
To: elecraft at mailman.qth.net
Cc: lists at w2irt.net
Subject: re: [Elecraft] 80m KPA1500 High reflected power problems

So above 3.675 it works fine?  Weird. When you say it was happening
previously, is that also with the KPA1500? First I would try another amp and
watch the SWR. I would also try bybassing any lightning protection devices
and coax relays so you just have coax and an antenna connected to the amp.

GL
John KK9A