On Jan 31, 6:34 am, Tim Shoppa wrote:
I've got a 130-foot doublet hanging 90 feet up in the air between two
trees. A pulley and a counterweight (a gallon of sand) keeps 20-some
pounds of tension on the line. Not a lot of tension but works great on
non-windy days. If the trees were stronger up at the top I
might try a heavier counterweight, but I'm not sure I'd be comfortable
doing this because I am really hanging from the treetops right now.

The feeder is approx 70 feet of 450-ohm window line (like twin-lead
but with little gaps every so often) to a standoff on the side of the
house. Yesterday when we were having 50MPH gusts this was billowing
out like a sail. I had twisted the window line a while back after the
last big windstorm, and that seemed to mitigate the sailing-ship kind
of effect, but not by a lot.

The counterweight and pulley did a great job of absorbing the wind
gusts. It was really impressive - when the big gusts came up, the
feeder billows out, and the gallon of sand shoots up in the air 30 or
40 feet above its usual position. I'm pretty confident that as long as
the trees didn't fall over in a hurricane, this antenna would stay up.
I even put a real stainless pulley with bronze bearings in, replacing
the one-dollar hardware store pulley, and am happy that I did. I have
seen the one-dollar pulleys get visibly corroded in a year or so on a
previous antenna.

But I'm thinking... if I just used two conductors of #16 copperweld
and some spacers to get true ladder line as opposed to window line,
would this billowing completely disappear, or drop to a tiny tiny
fraction of what it is now? Or would it just continue billowing the
same way?

What's preferable for such homebrew ladder line: solid copperweld,
stranded copperweld, solid copper, stranded copper, ???.

Tim N3QE

Hi, Tim.
I don't think you will want to use copperweld of any size for open
feed line. The wire will twist on itself in an uncontrollable manner.
Even with closely spaced spreaders, it will still be a mess.

I had then same problem with constantly windy conditions and window
line like you are using. One wire would break about once a year and I
would have to bring the antenna and feedline down and try to find the
break. We don't have real trees here in the Central Oregon desert, so
I use 4 section masts.

When we moved last year to a bigger place, I decided to put up a 160
meter lazy quad or horizontal loop and home brew 600 ohm open line to
feed it at a corner. I am still using 4 section masts, putting the
antenna at about 35 feet, but I used almost 125 ft. of feedline from
the house to the antenna. There are two supporting poles for the
feedline run, plus a rope and pulley for the house end.

I bought a 300 ft. roll of #14 copper motor winding wire on Ebay. It
has nylon or something similar for insulation. I doubled the wire by
tying one end to a fence post and walking out till I hit the end of
the wire, then brought it back to the post and tied it. I wound the
doubled wire back on the reel. I had a bunch of phenolic rods about
1/4 inch in diameter that I cut to 6 1/2 inch length. I drilled a hole
large enough to pass the wire about 1/4" in from each end of a rod.
Then I spent several evenings threading the rods onto the doubled up
copper wire. They were all bunched up together at one end. A real pain
to do!

More evenings were spent in the shop creating the feed line with the
spacers set at about 6' apart. I set a 2X12 plank on saw horses and
the wire and spreaders on one end and an empty take up reel on the
other. Each spreader is tied tightly to the feed line copper by
tightly winding a short length of #26 copper wire on the feed wire,
over the spacer and winding the rest on the other side. A blob of Duco
cement was then spread on the joint. Th section of finished feedline
was wound on the take up reel and then it was done all over again on
the next segment. This is a lot of work, but the old way of soldering
the tie wire to the feedline wasn't practical for this wire.

Eventually all was done and the feedline was installed. It works
quite well and the wind barely moves the feedline. I can detect no
stretching of the copper wire. Your installation may place more weight
on the feedline than mine, but should still work. The soft copper does
not try to twist.

Hope this gives you a little help from actual use.

73's
Paul, KD7HB