Hello Mauri and others,
> rather than looking for anything else, I'd like to point out my doubts
> about ability of standard antenna modeling software to give correct
> results in case of sharp wire angles.
> Moreover, my experience with modeling of moxon rectangles (AO6) has
> been quite disappointing with F/B, to the point I never thought to
> build any.
For those who would like to play a bit: From the equations used by MoxGen
(AC6LA) and as described in L.B. Cebiks page
(www.cebik.com/moxon/moxgen.html) I created a 40 meter 4nec2 model
containing similar equations. See below, 19 dB F/B. Just change the 'Fr=7.1'
value to create/calculate a model for a different frequency.
All this without saying something about the reliability of the model,
because I have no means of comparing things with practical results.
Arie Voors.
******************
CM Moxon rectangle by equation as descibed by
CM L.B. Cebik in www.cebik.com/moxon/moxgen.html
CM Comparison with model created using MoxGen
CM (www.qsl.net/ac6la/) yields equal results.
CE
SY Fr=7.1 ' Specify frequency
SY WD=1 ' Specify wire diameter
'
'SY WLI =11802.71/Fr, DW=WD/WLI ' If wire diameter in inches
SY WLI =299792.5/Fr, DW=WD/WLI ' If wire diameter in millimeters
'SY DW=WD ' If wire diameter in wavelengths
'
SY Wl=299.7925/Fr ' Wavelength
SY D1=.4342945*LOG(DW)
SY AA=-.0008571428571, AB=-.009571428571, AC=.3398571429
SY A=(AA*(D1^2))+(AB*D1)+AC
SY BA=-.002142857143, BB=-.02035714286, BC=.008285714286
SY B=(BA*(D1^2))+(BB*D1)+BC
SY CA=.001809523381, CB=.01780952381, CC=.05164285714
SY C=(CA*(D1^2))+(CB*D1)+CC
SY DA=.001, DB=.07178571429
SY D=(DA*D1)+DB
SY A=A*Wl, B=B*Wl, C=C*Wl, D=D*Wl ' Dimensions in meters
SY rad=DW*WL/2 ' Wire radius in mtr.
'
SY hgh=20 ' Height above ground
'
GW 1 35 C/2+B -A/2 hgh C/2+B A/2 hgh rad
GW 2 5 C/2 -A/2 hgh C/2+B -A/2 hgh rad
GW 3 5 C/2+B A/2 hgh C/2 A/2 hgh rad
GW 4 35 -C/2-D -A/2 hgh -C/2-D A/2 hgh rad
GW 5 7 -C/2 -A/2 hgh -C/2-D -A/2 hgh rad
GW 6 7 -C/2-D A/2 hgh -C/2 A/2 hgh rad
GE
FR 0 1 0 0 Fr 0
GN 2 0 0 0 13 .005 ' Use average ground
EX 0 1 18 1 0
EN
******************
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