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Hi Richard,
I think at least one of the metal masts I will be using to hang the 160m loop might lend itself to the vertical antenna you suggest. It is the one that is a full 50' in height, and will be out in the middle of the orchard where ground radials can be installed easily. Unfortunately this particular mast is the one farthest away from the shack, approx. 500 feet. Questions: 1. For reference purposes, what is the exact description (name) of this vertical? Any recommendations for information in print about this concept? 2. What band, or bands, would it be good for? (Assuming the guy wires are generally in the position of effectivenes as guy wires.) 3. Would it be monoband, tuned to an exact f, or possibly multiband? 4. Where would one attach the feed line and would a run of 500' to the shack still be worth the effort? 5. If I understand, the antenna is comprised of the mast itself (with telescoping sections securely and electrically bonded to each other) plus the "extension" of calculated lengths of the four guy wires, utilizing insulators at precise points before being attached to ground anchors. 6. How would the mast be mounted to the ground? Should it ideally be isolated from ground or contiguous with the ground? Theortically I could build a short wooden platform or something. 7. Other than the mast itself, the four guy wires, and some kind of system of radials in the ground, are there any other elements to this antenna that I should know about or be thinking about? Bill Richard Clark wrote: On Sat, 17 Apr 2004 18:14:58 GMT, zeno wrote: I am getting ready to put up my masts (5 of them) for a 160m full wave loop. For the most part I am using recycled telescoping tv masts which will be up around 50+ feet. Hi Bill, You are on the threshold of being able to do much more for slightly more effort. Let's suppose you use wire with insulators to break them up (generally only advised as a must below tower mounted beams so that opportunistic resonances don't mess up directionality and tune). Further, let's suppose all wires at the top have a good metal connection to the mast. Further, let's suppose each of these wires is broken such that the first insulator(s) is more than 25 or 30 feet above ground (straight down, I am not measuring along the wire). Nothing else matters beyond what you would then do for general construction. I presume that all masts are driven into the ground (or at least are not insulated from ground); and that at each mast you could build a radial ground screen of eight to a dozen wires as broad as those first set of insulators are out from the mast (probably 20 to 30 feet each). You then have the opportunity of developing four broadband vertical antennas (each with a gamma feed because of the grounded situation). There's a good chance they would operate on 80M without too much effort (you might push them to 160). Most of the work is in the top connection, and the first set of insulators - beyond that no commitments are needed if you simply decide to walk away later. That is easy with little difference in the up front effort. 73's Richard Clark, KB7QHC |
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