[Antennaware] Antennaware Digest

[Billy Cox]

CORRECTION: My spacings are for 80m, not 40m,
but the process is the same ... start with 
33' x 33' for 40m and away you go.

73/bc/NU

-----Original Message-----
>From: Billy Cox <aa4nu at ix.netcom.com>
>Sent: Feb 18, 2009 1:24 PM
>To: antennaware at contesting.com
>Subject: Re: [Antennaware] Antennaware Digest
>
>Paul, lets talk about the modeling first, and then 
>when the focus in more on the hardware side, that 
>would be a good time to transfer the discussion to 
>another forum perhaps.
>
>Back to the modeling now ... reflect on what others
>have shared with you as to their experiences ...
>
>Here's mine ... I had a 4x 80m array around my 80'
>tower with the "tie off point" for the full size
>wire elements being at 70', just below my 40m yagi
>which was on a TIC Ring Rotor at the time.
>
>Rather than having the 4 vertical bases spaced out 
>at about 65' for the typical 4 x setup, I ended up 
>using mine at 105' ... why you ask? Good question!
>
>When you "lean the elements tops in" using ground 
>mounted or elevated feedpoints, the average spacing 
>between the elements is decreased. 
>
>So instead of having 4 elements, spaced at 0.25, we
>end up with <depending on the slope> 4 elements at
>a spacing of less than 0.25, and more like 0.125w,
>which then causes challenges as to the proper way
>to phase and match the array.
>
><And I believe this is why we have mixed results
>reported with some of the K8UR type setups ...>
>
>Time spent with EZNEC confirmed the need to move
>the bases out ... so I offer that as a suggestion
>to try there with your situation.
>
>I would build up the 4x model, elements 100% vertical,
>and the 66' x 66' spacing noting the gain/F-B/SWR/etc.
>
>Next add in the 68' support and then tilt the verticals
>toward that ... note the changes in gain/F-B/SWR/etc.
>
>Now, moving all the bases outward by equal amounts, see
>what you can do to restore the gain/F-B/SWR/etc back to
>the values you noted in the typical 4x vertical setup.
>
>That help?
>
>73 de Billy, AA4NU
>
>-----Original Message-----
>>From: kg7hf at comcast.net
>>I must be subscribed to the wrong list.   I didn't know this was only for antenna models, what a surprise, but then again, I've only been subscribed for about 2 years now, and seen maybe 10 messages go by the entire time. 
>>
>>If it's for modeling, why not make a model then talk about it?    
>>
>>How about this to get it started (and I am not so good of a model maker).   Basically, a 40m 4sq, sitting on the ground but using the ~70ft mast to hold it, they slope a littel inward.     I'm sure it could be tweaked to make it much better.   I can send the entire model if desired. 
>>
>>Paul, kg7hf 
>>
>>                 EZNEC Demo ver. 5.0 
>>
>>Offset Fed Yagi -Uda for QEX                 2/18/2009     12:56:36 PM 
>>
>>              --------------- WIRES --------------- 
>>
>>No.          End 1   Coord. (ft)              End 2   Coord. (ft)       Dia (in)  Segs        Insulation 
>>      Conn.      X       Y       Z     Conn.      X       Y       Z                         Diel C  Thk(in) 
>>1       GND        0,      0,      0                0,      0,     70       #14   1           1        0 
>>2       GND       15,      0,      0              7.7,      0,     33       #14   5           1        0 
>>3       GND      -15,      0,      0             -7.7,      0,     33       #14   5           1        0 
>>4       GND        0,     15,      0                0,    7.7,     33       #14   5           1        0 
>>5       GND        0,    -15,      0                0,   -7.7,     33       #14   4           1        0 
>>
>>
>>
>>
>>Sources: 
>>
>>Wire #   % from E1   Phase 
>>
>>2                0                   0 
>>
>>3                0                  -90 
>>
>>4                0                  -90 
>>
>>5                0                 180 
>
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