Tom,
first thoughts are about grounding.
Though not familiar with the antenna, I assume it is basically a loaded
dipole and that the manufacturer claims it's matchable on all bands.

What is your R.F. grounding system like? is all the gear, particularly the
xcvr, amp and tuner, well grounded together and to a good heavy lead to at
least one ground rod?

Tom Fowle WA6IVG

On Mon, Aug 17, 2015 at 10:13:49AM -0400, Tom Behler wrote:
> Hello, everyone.
> 
>  
> 
> I guess this question is best directed to those who are familiar with the
> Cobra Ultralite Senior antenna made by K1JEC, but I'll take thoughts from
> anyone who is interested in replying.
> 
>  
> 
> Several years ago, I purchased a Cobra Ultralite Senior antenna from K1JEC,
> or Granite State Antenna in New Hampshire.  My main reason for making the
> purchase was to have operating capability on 80 and 160 meters.  The antenna
> itself is up about 35 to 40 feet, and is strung between trees on my
> property, and on a neighbor's property.
> 
>  
> 
> The antenna works well on 80 meters, and much of 160 meters, when tuned with
> my MFJ 998 auto-tuner.
> 
>  
> 
> However, I have never been able to get it to tune on 40 meters.  In
> addition, the tuning and performance are questionable at best on 20, 15, and
> 10 meters.  In fact, one problem I have noticed recently is that when tuning
> it on 20 meters, using my MFJ998 auto-tuner and my ALS600, I actually get RF
> coming through the PTT switch on my Heil gold line mic.  This, of course, is
> not good.
> 
>  
> 
> All of this is prompting me to try to correct the situation.
> 
>  
> 
> Several months ago, I contacted Joe at Granite State Antenna in New
> Hampshire, and he suggested that I make sure the excess ladder line is
> coiled in several loops, and is off the ground. I just double-checked this,
> and it is what we did when we installed the antenna. 
> 
>  
> 
> A ham friend of mine has suggested that I cut off the excess ladderline, and
> see if that helps.
> 
>  
> 
> I am reluctant to do this, because the instructions say not to do so, and it
> is one of those steps that will be difficult to reverse.
> 
>  
> 
> I am thinking of purchasing some RF chokes to help with the issue, bbut I
> still think there is a basic problem with my instalation.
> 
>  
> 
> Fortunately, my Alpha Delta DXCC tunes well on40 through 10 meters, but it
> would be nice if I could get the Cobra to do the same.
> 
>  
> 
> Any thoughts on this would be appreciated.
> 
>  
> 
> Tom Behler: KB8TYJ
> 
>