I'd bet it's the coil of extra coax. Any time I ever dealt with a coil of 
extra coax, it's caused some sort of similar problem unless it's the 10 
turns at the feed point to the antenna some antennas like. Other than that, 
I've seen more than one coil of extra coax, and not once has it ever led to 
anything good..
----- Original Message ----- 
From: "Tom Behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, June 25, 2015 9:16 PM
Subject: Interesting Problem With Alpha Delta DXCC Antenna Out Here At The 
RV Camp Site


>               Hello, again, all.
>
>
>
> Well, my Alpha Delta DX CC antenna is  finally up out here at the RV camp
> site.
>
>
>
> It is up a good 30 feet in the trees, with the  center and ends being at
> about the same height.
>
>
>
> I have done some preliminary testing of the antenna, and all looks good,
> with one exception.
>
>
>
> Specifically, the antenna tunes with the TS480 internal auto-tuner across
> the 10, 15, and 40-meter bands.  It even tunes across much of 80 meters,
> from about 3600 to about 3900 KHZ.
>
>
>
> However, I cannot get it to tune at all on 20 meters, once again, using 
> the
> TS480 internal auto tuner.  I even put my MFJ auto-tuner extender in line,
> with no luck.
>
>
>
> This is a bit disappointing to me, since 20 meters is one of my favorite
> field day operating bands.
>
>
>
> As I am scratching my head here to try to determine what might be going 
> on,
> I have two theories.  First, it has to be understood that I am limited to
> keeping the antenna within my lot space, and have to work with the 
> available
> trees.  This means that the legs of the antenna are probably only about at 
> a
> 60-degree or so angle from the center.  In other words, the antenna is 
> kind
> of like a folded  dipole in some ways.  I wonder if this could be 
> de-tuning
> the antenna on 20, although I'm not sure why it also would not bbe 
> de-tuning
> it on the other bands I mentioned.
>
>
>
> My second theory has to do with my coax feed line.  It turns out that I
> probably have about 40 extra feet of coax that I have coiled up underneath
> my station operating area.  I wonder too if this might have something to 
> do
> with the strange 20-meter behavior.
>
>
>
> Obviously, I'm happy that the antenna is usable on 10, 15, 40, and 80, so
> I'm sure I'll have a good Field Day exxperience.  But, the 20-meter 
> problem
> does puzzle me.
>
>
>
> Does anyone have any thoughts, or suggestions that I might try to get 
> things
> working on 20 meters?
>
>
>
> Tom Behler: KB8TYJ
>
>
>
>