[TowerTalk] Choke on feed point of dipole

[David Gilbert]

I already explained all of that.

Default ground specs were used.  (0.005/13 over Real/MININEC)

The ground plane antenna had four 1/4 wave horizontal radials 4 feet off 
the ground.  The bottom of the vertical dipole was also 4 feet off the 
ground.

Yes, the vertical dipole had greater field strength at low levels, but 
as I stated the difference was only a few degrees ... the max was at 17 
degrees for the vertical dipole and 23 degrees for the ground plane and 
there was barely a couple of tenths of a dB difference at the two maximums.

You can easily model this yourself (I used EZNEC Pro/2+ v2 with NEC5) if 
you don't believe me ... but I suspect that you already have in the past 
so I don't understand the questions.

Dave   AB7E



On 1/13/2026 1:21 PM, Jim Brown wrote:
> On 1/13/2026 11:09 AM, David Gilbert wrote:
>> but the maximum gain is almost identical.
>
> How did you model ground loss? What radial system? Any vertical with a 
> current maxima near the ground will need a return, and current in that 
> return has some loss.
>
> Once you've done all that correctly, save the vertical pattern of one, 
> then compute the vertical pattern for the other, and add the saved 
> plot to it. The half-wave antenna will have greater field strength at 
> low angles, and depending on your soil, may have less ground loss.
>
> http://k9yc.com/AntennaPlanning.pdf
>
> 73, Jim K9YC
>
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