Wire Moxon Rectangles for 40.doc

Wire Moxon Rectangles for 40-10 Meters
L. B. Cebik, W4RNL
Since a posting on QRP-L, the Moxon rectangle has drawn considerable attention. A full analysis of the antenna appears in the Spring, 1995, issue munications Quarterly. Basically, the Moxon rectangle is a wire antenna that can be fix-mounted or rotated. It is directional with about the gain of a 2-element Yagi (6 dBi in free space) and has an outstanding front-to-back ratio (greater than 30 dB in free space), with a very broad frontal lobe (-3dB beamwidth = 70 degrees, usable beamwidth = nearly 180 degrees forward). The basic outline of the antenna appears in Figure 1.

Since the article and the posting appeared, I have heard of essful constructions of Moxon's, one for a Field Day Novice station. I have also had two types of requests. One has asked for dimensions for other bands. The other inquiry wondered if the feedpoint impedance might be brought closer to 50 ohms. The original design showed a feedpoint impedance close to 80 ohms.
I remodeled the antenna with good results on both counts. Table 1 provides dimensions for the Moxon rectangle for 40 through 10 meters. The dimensions are not perfect simple scalings, because the length-to-wire- diameter ratio changes for each ham band.

Table 1. Moxon Dimensions for 40 - 10 Meters

Band
Design
Frequency(MHz)
Dimension (feet)
A
B
C
D
E
10