The W1AB Killer Antenna
I finally got XYL approval to hang some wire up in the woods! But I had to compromise and relocate my shack...
...just kidding, of course. The dog house belonged to Meicha, our black lab mix. She passed away two days after 9/11 -- yes, it was a really bad week. But now it makes a great place to stash the end of the feedline from my first outdoor antenna when it's not connected to the shack (more on that later).
The antenna is W1AB's Killer antenna that is described in his book "Low Profile Amateur Radio". The picture below was taken from the book -- and I followed the design quite closely (not that there's alot to it -- such a simple design for a "killer antenna").
My antenna's feed point is approximately 15 feet above the ground with the ends of the radials sloping down to about 8 feet. In the picture below, the antenna itself is just about invisible so I added bright lines to show the wires - pink for the vertical and green for the radials. If it wasn't for the 450-ohm ladder line (which is rather ugly stuff) this antenna would be just about impossible to see in the midst of the trees.
The missing link
The compromise that allowed me to obtain XYL approval is the removable segment of ladder line. This goes up when I want to operate and comes down when I'm done -- which is going to get old very quickly, but the performance over the attic dipole is very motivational. I picked up one of those extension cord spools with crank handle for $5 which makes the set-up and take-down operations take about 3 minutes each.
The first connection is well back in the woods and is shown below. I've improved the rope "support" since the picture was taken to include a plastic hook on one end so there's no need to tie and untie knots each time.
Here's a shot (below-left) of the objectionable span that comes down each night -- it takes a bit of a turn as it leaves the woods, supported by a cup- hook that is as high up as I can comfortably reach. And another shot of the ladeer line as supported by the corner deck post.
The second connection is down where the line enters the lattice work as shown above, and in more detail, in the photo below. Each of the connections uses gold-plated banana jacks/plugs and I've tried to make then somewhat waterproof (for what it's worth).
The line then crosses diagonally under the deck supported by pvc stand-offs (same technique as I used for the attic dipole, more or less) and emerges just outside the basement window. The window is plexiglass and contains two banana jacks to which the line is connected. Inside the basement the feedline (with banana plugs) continues to the shack, again with pvc stand-offs guiding the way.
Initial results are very encouraging as compared to attic dipole. The K2 can switch between the two antennas with the touch of a button, so it's quick and easy compare. I am definately transmitting a stronger signal (and louder audio) according to receiving stations, and reception is definately better -- some weak stations disappeared completely when I toggle to the attic dipole.
I've made contacts on 17m, 20m, 40m and 80m with this antenna, but 20m is still the best bet for a lunch-break DX contact or two with 40m as a close second (and not so DX).