[Towertalk] Need EZNEC model for 40-2CD  40-2CD EZNEC Model
   
    Bill Tippett
     
    btippett@alum.mit.edu
       
    Tue, 09 Jul 2002 14:15:02 -0400
    
    
  
        Here's a quick look using EZNEC models I had on hand, 
all assuming EZNEC high-accuracy "Good" ground (0.005, 13):
                                     dBi  @ peak TOA
4-square (EZNEC's 4square.ez)        5.34 @ 25 deg
4-square (EZNEC's 4sqtl.ez)          5.29 @ 25 deg
Dipole @ .5 wl                       7.63 @ 27 deg
2 el Yagi 16' boom @ .5 wl          11.56 @ 26 deg (+6.2 dB over 4SQ)
The 16' boom model happens to be the only 40M 2 element I had but it 
should be a reasonable comparison to the 40-2CD (23' boom should give 
higher gain but probably +0.5 dB loss due to loaded elements).  The 
above gains for the dipole and Yagi would drop at lower heights and I 
would not personally not use them at less than .5 wavelengths.
        The above is essentially what I posted previously so my
memory did not completely fail me:
        "This should be no surprise.  Even a dipole up 1/2 wavelength
will beat a 4-square.  I recall a dipole's gain is in the order of 2-3 
dB over a 4-square for equivalent grounds.  Add another 4-5 dBd for a 
2 element Yagi and you are around 6-8 dB over a 4-square.  The only 
place a 4-square can realistically compete with a Yagi is if you are
over salt water."
                                                73,  Bill  W4ZV