Steve:

I will try to get some visual clarification on how the excess ladderline is
arranged.  I think it is in about 3 or four loops, each three or four feet
in  diameter, and I think the loops are arranged in a zig-zag fashion.  I'll
also get clarifrication on how far they are from any metal structures,
including my support mast for my other antennas.

I am not at all opposed to cutting off the excess ladderline, but I don't
know if I would want to cut it more than once, since I'd want to bbe able to
put things back together if cutting off the excess makes things worse.  Of
course, I could always solve that problem by just ordering some new ladder
line and making one replacement segment.

Regarding the hot mic issue on 20 meters, I don't think it is a new problem.

I say this for two reasons.

First, the antenna has never worked all that great on 20 meters, and is
significantly out-performed on that band by my Alpha Delta DXCC.

Second, I do not experience the hot mic with 100 watts;  I've only
experienced it when using my ALS600 amp with about 400 to 500 watts out.  I
don't remember ever trying my older AL811H on 20 meters with the Cobra, but
I don't think I did because of the antenna's degraded performance on that
band since I  put it up.

I did check the connections on my 4 to 1 balun, and they feel very sound.
They also don't seem to be corroded.

In summary, I agree with you;  I want to see if I can get to the bottom of
my problems with the antenna on 40, 20, 15, and 10 rather than masking the
symptoms with ferrite chokes or something like that.  In addition,  I'd like
to do it before contest season starts, and the snow flies.

I am  happy that the antenna does so well on 80 and 160 meters, which is why
I bought it, but having it perform better on the higher bands would be a
definite plus.

Tom Behler: KB8TYJ




-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Steve Forst
Sent: Monday, August 17, 2015 3:51 PM
To: [log in to unmask]
Subject: Re: Question About Cobra Ultralite Senior Antenna

Tom,


You may wind up having to cut the ladder line some as John has done. 
Even though the builder says snot to, I think many people cut the line to
resolve problems. Maybe in 5 foot increments until problem is solved, or
until the line gets so short that he antenna is useless.

Before I got out the snips, I would try rearranging the excess line. 
Maybe a zig-zag, or some other configuration other than coils. If the excess
is close to the house, maybe get it out in the yard more.

Ferrite chokes are nice, and I use a ton of them here, but you should try
and resolve the problem if possible, rather than just cure the symptoms (hot
mic). Did this just start? Did you check the connection from ladder line to
balun?

A quarter wave counterpoise for  the hot band may help.

If it came down to it, I would have no problem pruning the line. You can
always reattach it later, although cutting is the easy part.


73, Steve KW3A
 > Tom,






On 8/17/2015 10:13 AM, 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
>
>
>
>
>