Topband: K9AY Loop Questions

[Artek Manuals]

Comments below

On 1/7/2022 6:23 AM, Roger Kennedy wrote:
> <SNIP>
>
> But I picked up on people saying that EZNEC doesn't model these antennas
> near the ground very well.

This is very true of EZENEC based on NEC -2....EZENEC PRO 4 based on 
NEC-4 depending on attention to detail and uniformity of soil conditions 
can produce results for models near ground that represent reality.  
NEC-5 was intended to address  the lack of uniformity in the ground 
medium ( i.e having half your ground plane consumed by 3 story apartment 
building as an example) but the modeling could becomes quite an 
exercise. Unfortunately the father of NEC-5 passed away unexpectedly and 
left its development in limbo  and a fair share of questions and 
possible bugs. When last I talked to LLNL they were still searching for 
a replacement for Jerry

<SNIP>

> I think part of the reason is that DX Propagation on 160 is usually much
> higher angle than on 80m . . . but I also think that there is more low angle
> radiation from my Dipole than EZNEC would suggest !

This is very true especially near gray line. I have noticed on numerous 
occasions the the F/B on my Beverage and BOGS becomes very poor at 
gray-line only to return to expected performance later in the evening. 
Popular wisdom suggests that most 160 DX occurs at 15-25 degree arrival 
angle . I suspect that gray line propagation arrives due to "ducting" at 
even higher angles. I am toying with the idea of building a loop on a 
gimble that would allow  rotation not only for azimuth but for elevation 
as well. I suspect however that I will find that the arrival angle can 
change quite rapidly making it hard to track and is one of the reasons 
for deep QSB

Dave

NR1DX

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Dave Manuals at ArtekManuals.com www.ArtekManuals.com

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