[R-390] 1000' vertical delta loop

[blw]

>post it, Barry, for everyone to enjoy.
>
>
>> If anyone is interested in how I made a 1000' delta vertical loop
>> by myself
> >between 2 trees contact me and I'll try  to put together some
> >plans to send
> >you. Each side was about 24', and I think I had 12 turns of wire. It was
> >very small, compact, and hard to spot even with orange wire. I
> >think it took
> >less than 2 hours to build these once I knew how to do it alone.
>
>Don Reaves W5OR
>w5or@comcast.net
>R-390 list manager



Don and list,

Here is how I made and raised a 1000' vertical antenna with a delta shape
between 2 trees. One point of the antenna was towards the ground and the
other 2 points were at the top for suspending between the trees. The bottom
point was tied to a stake. This was a very good point for controlling sway
and twisting forces in high wind conditions. I also untied the bottom a few
times when the weather was extremely destructive here in Alabama to give the
antenna room to sway with the trees. It remained in good condition for 2
years and never tore.

Each side of the antenna was the same length and not assymetrical. I had 2
trees that were about 50' apart, so that gave me roughly about 12' on each
side to suspend the antenna. I'm not sure of the measurements at the moment,
but I think each side was 24' long and I had 12 wraps of wire all the way
around. This was a problem at first because I lived in the country and
didn't have anyone to help raise it once I built it.

I put 3 stakes in the ground for the outer dimensions that I wanted. 2 of
these stakes were in line with the trees I wanted to use. I tied a short
line to each stake with an insulator egg on the end of the line. This was to
provide a suspension line point and to begin the first wrap of wire for the
outside of the antenna. I wrapped each egg twice for strength with the first
turn of wire. This gave me the outer shape.

Doing the inner turns meant using weather resistant wire ties. I got the
thickest I could find. Each subsequent turn was several inches inside of the
previous turn for spacing. At each point of the antenna I put a loop of wire
tie to give stretching room and that inch or so of spacing. The next turn I
would tie the wire tie loop to the previous tie like a chain. I periodically
pulled the wire a bit taut to keep the shape and the antenna off of the
ground. 

I ended up with each turn going inward towards the center. Each point of the
antenna was a large wire tie loop tied to the previous wire tie loop. You
can pull the wire tight as you unreel it from point to point to keep a good
shape and to keep the wires from crossing over each other. You have big
problems if that happens and you don't correct it right away.

I had painted 9 thick wooden dowels for spreaders. I used the wire ties to
tie off each turn of wire to the dowels, 3 dowel spacers per side. This took
the most time in the construction process, but this worked well over several
years. I've thought that if I build another one I should drill however many
holes for the turns in the dowels instead of using wire ties. I could put
the spool of wire on a stake and pull the wire through the holes as I build
the sides. That probably would be best if long term stress and pulling
evened out throughout the wire. It seems that it should work and balance
out. I would have to tie some of the wire to the dowel spacers to keep them
from sliding, if you can picture what I'm talking about.

Once I had the antenna finished it was only a matter of of getting the lines
over branches and pulling each side up a few feet at a time. I would tie off
the line temporarily and go do the other side. After a few iterations of
this the antenna was up in the air and the top side was straight and taut. I
tied off the bottom point to a stake. My feed point was one of the top
corners so that I could pull the wire at a 90 degree angle away from the
face of the antenna. I wasn't completely sure about the feed point part of
this, but I did get 90 degrees angle away from the antenna.

I used this antenna for a lot of HF and MW DXing. It did get some noise but
nothing that I couldn't live with. I chalked it up to a good gain. It worked
well as a general purpose antenna and even better for MW. It was never
planned based on frequency formulas as I just bought a 1000' spool of wire
and wanted a 1000' antenna. I had built a 1000' Beverage and was completely
disappointed in it. I'm sure that this isn't the best way to approach things
for everyone, and maybe my next one will be cut to a length somewhere in the
160m band for MW. You can get some impressive logs from random lengths like
mine on LF, so length isn't all that critical. Maybe I'll go for 2000' if
this is going to be a permanent LF/MW antenna. I didn't have my RBL-5 back
then, but I bet I would have had some good logs. It seemed directional, but
not sharply so when I checked stations with other antennas.

The thing that always surprised me about this antenna was the small size of
it and how hard it was to spot from a short distance away. Sides of 24' is
not all that big.  It was always hard to believe that there was 1000' of
wire in the small triangle shape. The spacing of either 2 trees or 1 tree
and the side of a house isn't that critical either. I think you could run
long lines to the closest trees and still have good support.



the other other Barry