[TowerTalk] Vertical plans

[David Gilbert]

The top hat tubes sound pretty unwieldy to me.  You're going to need to 
guy the vertical section in a couple of different places anyway, so why 
not just make the top set of guys partially out of large diameter 
aluminum wire?  I built a similar antenna several years ago, and 48 feet 
of 2 inch diameter tubing required four 1/8 inch diameter wires each 
about 11 feet long to resonate on 80m.  I modeled it ahead of time with 
EZNEC and it required almost no trimming when I built it.  The aluminum 
wires were each wrapped once around the tubing and fastened  with a 
sheet metal screw, then angled out at about 45 degrees if I remember 
correctly.  Each of course had insulated line for the rest of the length 
to their anchor points.  I don't guarantee that these dimensions will 
work exactly for you, but they should be close.  The diameter of the 
tubing and the top hat wires both make a difference.

73,
Dave   AB7E


W5CPT wrote:
> Here is what I plan to do for an 80M vertical.  Please feel free to advise what else I might do or to warn me what not to do.  
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> I am going to Dallas TX in June for HamCom and while there I plan to visit Texas Towers and purchase enough aluminum to build an 80M vertical.  I plan on getting 4 each 12 foot pieces of tubing starting at 2" for the main radiator. I also plan on getting 3 each 12 foot pieces of 3/8ths tubing for the top hat.  This will give me a 46.5' tall radiator with a six part 6 foot each top hat.  My plan is to cross drill the top section which will be 1.625" and space the three sets of spokes about an inch apart as close to the top as I can drill. I will use hose clamps to keep them in place. The base will be a set of insulated clamps from DXEngineering to a plate attached to a 4X4 sunk in the ground. 
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> I then plan to erect it over about a mile of ground mounted radials evenly distributed in a circle in my yard (I love living out in the country) and sticking my MFJ-259 on the feed to determine the amount of matching I will need.  I assume I will need some inline L to bring it to resonance.  I realize it will probably not cover the whole band but I will tune it for the center and let the tuner in my radio widen the usable bandwidth. 
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> Your comments please.
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> Clint - W5CPT
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