[TowerTalk] NA8V on 10M (Story)

[Bill Fisher, W4AN]

Subject: Re[2]: too high antenna?
To: Bill Fisher - W4AN <w4an@contesting.com>

     Well, guess I have to disagree w/ you.  Talking 10 m., I was comparing 
     170' with 90'.  90' is already relatively high in terms of wl., 
     therefore one won't see the difference from a REAL high antenna as 
     often, which most often is at the lowest angles.  Also, I was speaking 
     in reference to 1) a stack - where if you have big beams you get 5db 
     over a small, single beam and 2) frequently  the "off" or multiplier 
     antenna needs to break a pile-up.
     
     I agree with you about 20 meters, having used Duffy's stuff, and 
     having had antennas at all different heights.  Remember that in your 
     example of 210' on 20 it's only 105' on 10 - I think that that may be 
     a point where diminishing returns begin to come into play - Anecdotal 
     evidence aside (K6EBB worked a G on 10 w/3el at 180', nobody out here 
     worked one) - in single op contesting particularly rate is a key 
     factor, and the REAL high antenna won't give you that very often 
     (still talking 10 here - REAL high must be defined in terms of wl, NOT 
     in terms of common hardware - 200' is not real high on 40)
     
     I remember 2 specific instances on 20:  listening to a UA9, stack of 
     5el/46'boom at 65/125 and a 205ba @80'- bottom beam, barely readable, 
     205 - s5-7, top beam - s9, and stack well over 9.  The other was a WPX 
     with a single 205ba at 160' - at 10z sunday morning, I could hear all 
     the west eu talking to each other, not working any US.  It was like I 
     was on their continent.
     
     Bottom line:  very low angle is often far superior, BUT is there a 
     point where the lower angle doesn't propagate any better?  
     
     On 10, where high (w/l) antennas are easy (100-120'), one needs to get 
     as much gain as possible to differentiate from the crowd.   That would 
     be as big (boom) a stack as practical- and 3 or 4 high would be a way 
     to go.  Note how dominating w9re has been on 15 the last few years 
     since he went to his 4 high, both gain AND low angle.
     
     As far as gain goes, I would expect my 42' yagi (a dl1bu) to have 
     2.5-3db gain over the 20'(w2pv) one.  That is the same as a doubling 
     of power.  While the g3 may not notice a big difference, the t77 will 
     pick you out of a pile a HECK of a lot quicker.
     
     btw, you'll love a full size 3 el 40.  Might want to keep it on the 
     low side?  100-120'?  Mine was frequently too high in the mid-opening, 
     although a killer at 0800z and before sunset (2nd lobe?).  it was at 
     170'.
     
     Greg

Bill Fisher, W4AN (EX KM9P)
http://www.contesting.com 






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