[Antennas] Tilted Delta Loop

2002年10月10日 17:01:56 -0400

Steve, I once had two 80 meter loops up at the same time. One was about 60
feet up and parallel to the ground. The top of the other was about 70 feet
up and hung straight down with the bottom being only a few feet off the
ground and was broadside to Europe.. In general the vertically oriented
loop was about 10 db stronger into Europe than the horizontal loop. On the
other hand the horizontal loop in general was 10 db stronger than the
vertical loop within 500 miles. I eventually replaced them both with one
loop just as you describe sloping about 45 degrees toward Europe.
Unfortunately at this point I had nothing to compare against, but my feeling
was that I had pretty much split the difference as expected.
Over time I fed all three loops at a variety of points - top, bottom center,
bottom corner, 1/4 wave down one side. While varying the feed points made a
difference in the impedance I never saw any appreciable difference in
performance.
Incidentally, while it was a rare occurrence, there were nights when the
horizontal actually outperformed the vertical into Europe. I always assumed
that this was a "very high angle night".
Regards, Merv