Antena Multibanda

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| |A multi-band wire antenna that performs exceptionally well even though it confounds antenna modeling software| |
| |Click FAQ to read a list of frequently asked questions and answers about the W5GI Mystery Antenna. | |
| |The design of the Mystery antenna was inspired by an article written by James E. Taylor,W2OZH, in which he described a low profile collinear coaxial array. This antenna covers 80 to 6 meters with low feed | |
| |point impedance and will work with most radios, with or without an antenna tuner.  It is approximately 100 feet long, can handle the legal limit, and is easy and inexpensive to build.  It’s similar to a G5RV | |
| |but a much better performerespecially on 20 meters. | |
| |The W5GI Mystery antenna, erected at various heights and configurations, is currently being used by thousands of amateurs throughout the world.  Feedback from users indicates that the antenna hasmet or | |
| |exceeded all performance criteria. The “mystery” part of the antenna comes from the fact that it is difficult, if not impossible, to model and explain why the antenna works as well as it does.   The antenna | |
| |is especially well suited to hams who are unable to erect towers and rotating arrays.   All that's needed is two vertical supports (treeswork well) about 130 feet apart to permit installation of wire | |
| |antennas at about 25 feet above ground.   | |
| |The W5GI Multi-band Mystery Antenna is a fundamentally a collinear antennacomprising three half waves in-phase on 20 meters with a half-wave 20 meter line transformer. It may sound and look like a G5RV but | |
| |it is a substantially different antenna on 20 meters.  Louis Varney’s antenna, although three half waves long, was an out-of-phase aerial.  Mr. Varney had two specific reasons for selecting a 3 half waves on | |
| |20... he wanted afour-lobe radiation pattern, at least unity gain and a low feed point impedance.   The Mystery antenna, on the other hand,  presents a six-lobe pattern on 20 meters, gain broadside to the | |
| |antenna, and also low feed point impedance to simplify matching the antenna to the rig.   Additionally, the Mystery antenna is designed to work at least as well, on the other HF bands as aG5RV.  In short, | |
| |the Mystery antenna is a sky wire that incorporates the advantages of a 3 element collinear and the G5RV antenna. | |
| |In its standard configuration, a collinear antenna uses phase reversing stubs added at the ends of a center fed dipole. Thesestubs put the instantaneous RF current in the end elements in phase with that in | |
| |the center element. You can make these phase reversing stubs from open wire line or coaxial cable. Normally, a shorted quarter-wave stub is used, but an open-ended half wave stub would also work. The problem | |
| |is that the dangling stubs are unwieldy and or unsightly....