[Elecraft] [OT] High SWR on 20 and 40

[djmd]

Hello,

I have been trying to troubleshoot my antenna system, and have been trying
to avoid the dreaded "high swr" post, but I've run out of ideas, so I'm
turning here. 

First let me explain my system. 67' dipole fed by 16' of window line. That's
connected to an Elecraft balun. From the balun, there's a short piece of
coax going to a barrel and into the basement (through a piece of cement
backerboard. From inside the basement, there is another piece of coax, about
12', connected to the barrel, and going up into the bedroom directly to a K2
with an autotuner.

Before the K2, I was using a Yaesu FT840 with an MFJ tuner. After tweaking
the window line length and the actual length of the dipole, I never really
had a problem with SWR (well, according to what the MFJ was saying, which
may or may not be totally accurate.) Usually 1.5:1 or under on all bands.

With the K2/KAT2 in place, the SWR reported by the tuner is all over the
place. The only one that gets less than 1.5:1 is 30m. Most bands are pretty
random, anywhere from 3:1 to 7:1. However, on 20 and 40, it generally does
not get below 9.9:1. 

I've tried 4 different lengths of coax between the barrel (inside) and the
rig... 3', 6', 12' 20'. I've tried a couple different lengths between the
balun and the barrel on the outside. 

When I attach the balun directly to the K2 I get <1.3:1 on all bands (most
are 1:1.) With a short piece of coax between the rig and the balun, I get
the same results. I've also attached my dummy load to the barrel on the
outside of the house, and tested it from the shack, and I saw 1:1 no
problem. 

I totally understand the concept that if "A" works and "B" works, "A+B"
doesn't necessarily work. I understand it's a whole system. But I've tried
so many different combinations of coax on each side, and don't understand
why my SWR is basically infinity:1 on 20 and 40, when they seemed to match
reasonably with the old system. I have not tried different lengths of window
line between the dipole due to the fact that I had it perfectly trimmed for
my old system. But I have plenty of it and would be open to trying anything. 

Just trying to get the most I can out of my modest 10W. :) Any suggestions
would be appreciated!

73,

Dave
K8DJW
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