I have used Hi-Z receive arrays, starting with the four element Hi-Z 4 (a square, 60’ on a side) and then moving to the three element Hi-Z 3 (a triangle, 50’ on a side) because it fit on my property better. The bulk of my comments below will pertain to the Hi-Z 3 and my experience has been almost all on 80m, and though I used the original element pre-amps that Hi-Z provided when the system was first introduced I have migrated to the newer PLUS6 designs. I have been impressed with the Hi-Z 3 and recommend it.
My Hi-Z 3 array works well. Eight years ago I began playing around with basic Beverage designs on 40m, where experimentation is easy because dimensions are more manageable. Like many low band operators before me, I was stunned at the improvement in receive ability. On 40m – after years of wire antennas, vertical arrays, and some serious yagis – a 145’ Beverage based on K1FZ hardware surprised me at how such a simple, inexpensive receive antenna could make such a big difference. I then played around with 300’ and 450’ Beverages on 80m, which also worked well. But I also learned their limitations – they aren’t steerable, they take up a lot of space, winter animals get snagged in them, and the need to put them up in the fall and take them down in the spring was wearing on me. I tried a Hi-Z 4 array and saw that it was a very viable alternative to Beverages and solved all the problems that Beverages presented – they WERE steerable, I COULD leave them up all year, and winter animals managed to leave them alone. I then swapped the Hi-Z 4 for a Hi-Z 3 and spent three years doing A/B testing between it and some 450’ Beverages, and though the testing was not “scientific” I concluded that the Hi-Z 3 array “heard” every bit as well as the Beverages AND it had all those other benefits. For the last two winters I have not put up my Beverages and now I have no plans to ever do so again – the Hi-Z family of receive antennas will be my low band receive antenna choice. There are other things worth knowing – one is that this is an antenna that “wants to work.” The owner of Hi-Z, K7TJR, cautions against abuses – for example, he advises that the antenna should be placed clear of other antennas, metal, and trees. But in my experience with the antenna, as well as from posts from other owners, the system is “forgiving” and these antennas seem to do just fine when located in compromised places. Mine are near, and even right under, trees and close to other antennas. Though it’s possible that a detailed analysis, with near and far-field signal sources, and some sort of informal antenna range, would reveal shortcomings it sure doesn’t feel like I’m giving up anything. In summary, the Hi-Z 3 has made casual operation on 80m much more of a pleasure and has also enabled me to get more serious in working DXCC countries that I never dreamed possible on 3.5 mHz – countries like XW, HS, BY, S2, XX9, VK9C, and 9M2 – all hard to work from W1 on ANY band.
K7TJR has made it easy to install and operate one of these arrays. Though there is ample reading available on the theory behind these systems if one wishes to pursue it, the Hi-Z array will work quite well if one just follows the directions laid out in the user manual. There are very few rules that need to be followed, and from my experience all that needs to be done is for the (1) element spacing to be as precise as possible, (2) RG6 coax feedlines from the array controller to the element base amplifiers to be equal, and (3) length of the short delay line on the controller to be consistent with the spacing of the elements (all this is explained in the manuals). Perhaps the only challenge you will face is in fabricating the vertical elements that compose the array itself. Hi-Z makes this easy by selling, through DX Engineering, a kit for building 24’ elements. I elected to fabricate my own and use 18’ elements, which seem to do fine, and system performance is not hypersensitive to whether you use 24’ or 18’ elements.
Superb product support is provided by the company owner, Lee, K7TJR. Lee is quite passionate about the technologies used in his products and he’s committed to making his users happy and successful with his arrays. The product line has evolved in response to feedback from users, he’s responsive in answering technical and operational questions, and he’s very patient with those of us prone to making self-inflicted errors or who fail to read manuals. In short, Lee is a good guy and he stands behind what he designs and builds.
By the way, if you got this far in the review, one question you might ask yourself is whether you ought to just go with a Hi-Z 3, instead of considering bigger and more complicated arrays (like the Hi-Z 4). Well, I implied that I wasn’t going to get into any antenna theory, but there’s one concept worth knowing about called “receiving directivity factor,” or RDF (see W8JI’s website). This is a case where “more is better,” and by going from a three element array to a four element array you gain enough directivity to make the change worthwhile. But that may not be for everyone, and you might just find that the three element array improves your life enough to install it and leave it alone. And by the way, with 50’ sides on the array’s triangle I have found that it receives well on 160m, 80m, 40m and 30m.
Hi-Z arrays are available through DX Engineering, and they are responsive in filling orders and getting the product to you as fast as possible. Give a Hi-Z array a try, I believe you will be pleased with the outcome.
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