[OKDXA] K9AY loops

[Kim Elmore]

Hi Jim,

My tower is only about 48 ft tall with an 8 ft mast, KT34A and a 
40CD2 on it. I didn't modify the KLM, so all the elements are 
insulated form the boom, That means I really have only the booms and 
one element of the 40CD2 as top loading, so mine is pretty short electrically.

I think I'll run the shunt all the way to the of the tower, and space 
it about 24" or so. I have a couple of vacuum variables, 1000 pf and 
500 pf, good for 8 kV and 10 kV, respectively, so I have capacitors. 
I think I also have a coil I can use if I need to lash together an 
L-network to get a match. Once I have something that works, I'll get 
an enclosure and maybe a motor drive for the capacitor so I'm not 
essentially rock-bound.

I'll only use the tower for 160 as I have a F12 Sigma 80 for 80 m. 
Last night, I could barely hear the E7 on 80 m using the Sigma 80. I 
really wish I'd had the loops up and going to do a rx comparison. 
Maybe this weekend...

73,

Kim N5OP

At 06:36 AM 11/6/2007, you wrote:
>Hi Kim,
>
>I am using a shunt fed tower on 160m.  Just use a
>variable capacitor in series with the shunt.  I vary
>the cap for lowest SWR.  I have a 30 foot shunt out
>abt 18 inches on a 70 foot tower and the cap is abt
>560 pfd's.  Any variable cap will work for testing but
>you will need to get something that will handle your
>power for operation.
>
>Jim
>
>--- Kim Elmore <cw_de_n5op at sbcglobal.net> wrote:
>
> > Well, I've finally put up my K9AY loops, obtained
> > from Array
> > Solutions.  It includes the fiberglass mast and
> > phase switching box
> > at the base, along with control head/preamp.
> >
> > That said, it's not all wired up yet. It's a bit of
> > an ordeal to get
> > the thing up, though nothing terrible. The
> > instructions have some
> > rough edges that led to some minor confusion, though
> > nothing serious.
> >
> > I still need to fabricate a coax line and control
> > cable out to the
> > control box, dig a shallow trench to put 'em in, and
> > do some final
> > trimming on the loop wires to get everything snugged
> > up. The antenna
> > will be at the end of about 300 ft of transmission
> > line, and the
> > instructions say that long lines can lead to
> > ground-loop issues.
> > Burying the wires helps alleviate any such problems
> > (so Array Solutions says).
> >
> > I'm anxious to try this thing out given everything
> > I've read about
> > it, but I gotta do one thing at at time.
> >
> > I still need to attach the shunt feed to my
> > relatively short tower.
> > Anyone with experience in this regard have any
> > suggestions?
> >
> > 73,
> >
> > Kim Elmore
> >
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