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Hi Earl,
There is another way to skin this cat. It trades height for
horizontal space and it is mechanically simpler than the top
loaded version. Since the corners are farther apart, there is a
bit more directivity than for the smaller equilateral designs.
You could think of this as top loaded with the loading
incorporated into the loop wires.
See what you get from modeling this.
1. Apex at 90 to 95 feet (not critical)
2. Equal length side conductors
3. Bottom conductor at 12 to 15 feet above grade.
4. Length of bottom conductor as required for resonance at 1.83
MHz
5. If modeling with tower, spacing from tower 5 to 10 feet.
6. Plane of loop perpendicular to earth's surface.
7. Feedpoint at either of the bottom corners (not part way up
side conductor)
That should match 50 ohms close enough to connect the cable
directly through a number of beads sufficient to isolate the
feedline shield from the antenna currents. We have built a
number of these. They are relatively low Q and quite effective.
73, Eric N7CL
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