From NEC2 to the real world with accuracy
			 
			 
			
		
		
		
			
			On Mar 12, 9:50 am,  wrote: 
  If I might anticipate because the copper oxidizes and presents a high 
  resistance to current, I would point out that enamel is even more 
  resistive and the current isn't going to travel through it either (the 
  current will travel through the proverbial path of least resistance - 
  under the coating of resistive layer covering no matter what it is 
  composed of). 
 
 (I am addressing more than one post with this response) 
 
 Basically I want to use copperweld for durability. Its not a matter of 
 saving money over hard drawn copper. I have no experience with (bare) 
 copperweld,  but I have read that if you get a nick in the copper 
 layer, basically the steel will start rusting away at that point (very 
 quickly). So I don't have problem using some enamel to protect it (and 
 have done this in the past with hard drawn).   I am using copperweld/ 
 insulated wire for my low band antennas  - but anyone who has actually 
 built a quad knows insulated wire is much too heavy, esp. when you are 
 dealing with 5 bands. 
 
 I have used hard drawn copper with enamel on it on 10 meters and never 
 had a problem with a wire breaking in 10 years. So, I am not really 
 sure if I need copperweld, but I have no expierence with larger quad 
 loops. The goal is to have this thing be reliable. 
 
 Regardless still - whatever I wire I use - even if it was bare #12 
 solid copper wire, I still want to go through the exercise of getting 
 the wire I actually used in sync with my model. So, I'd rather focus 
 the conversation on that topic. 
 
 With respect to manually tuning the quad (reflector) after its up, 
 yes, that seems to be the conventional wisdom.  How practical and 
 possible is that for me? Mine will sit on 72' US Tower crankup/tilt 
 over - short of renting some huge bucket/boom, I can't see myself 
 manually tuning it when its up. The best I will do is take some type 
 of field measurements and see if it displays anything close to the 
 pattern NEC2 predicts - or better yet, just see if I am happy with it 
 as is. I did not have to make any adjustments to the monoband yagi 
 that went right from NEC2 to the tower, so, I am hoping for the same 
 good fortune. 
 
 -Scott, WU2X 
 
Scott, you are introducing sharp corners to your new antenna so NEC 
will stray from accuracy. 
Art 
		 
		
		
		
		
		
		
		
		
	
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