[TowerTalk] 80 mts four square or yagi?

[Pete Smith N4ZR]

The *magic* of 1X/2X spacing is that it tends to cancel the second 
vertical lobe.  Depending on your takeoff angle needs, this might not be 
a good thing, but on the other hand if you can switch to use just the 
lower antenna you'll find that it emphasizes the same angles that the 
stack cancels. You might look at 50/100 ft spacing too.  HFTA's problems 
with close spacing begin *much* closer than that - IIRC, <10 ft.

73, Pete N4ZR
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On 3/9/2015 9:11 PM, W0MU Mike Fatchett wrote:
> What values did you get using HFTA.  HFTA has some issues with very 
> close spaced stacks.  The numbers are wrong.
>
> Mike W0MU
>
> On 3/9/2015 7:09 PM, Jorge Diez - CX6VM wrote:
>> Thanks Jim
>>
>> Sorry for the delay, just returning from along trip after ARRLDX SSB
>>
>> Is curious HFTA. It stopped my project for a two stack for 20 mts yagís.
>> Since many contesters told me to put it at 69/139 ft, HFTA told me 
>> that this
>> is not the best distances.
>>
>> OK about your document, will read it, but here we don´t have such 
>> facilities
>> than in USA to know ho´w the ground conductivity, the terrain data, 
>> etc, etc
>>
>> 73,
>> Jorge
>>
>>
>> -----Mensaje original-----
>> De: TowerTalk [mailto:towertalk-bounces at contesting.com] En nombre de Jim
>> Brown
>> Enviado el: domingo, 08 de marzo de 2015 02:44 p.m.
>> Para: towertalk at contesting.com
>> Asunto: Re: [TowerTalk] 80 mts four square or yagi?
>>
>> On Sun,3/8/2015 10:06 AM, Jorge Diez CX6VM wrote:
>>> Wish someone have some analysis or field test to compare a 4SQ with
>>> sixty 1/4 WL radials each vertical and a 3 element wire yagi with boom
>>> at 115ft
>> This is not exactly the answer, but it should help you think about it.
>> http://k9yc.com/VertOrHorizontal-Slides.pdf
>>
>> Also, if the land around you is not flat, you also need to study and use
>> HFTA extensively. It comes on the CD with the ARRL Antenna Book. HFTA 
>> tells
>> only about horizontally polarized antennas, NOT verticals, because they
>> interact with the earth very differently. The slides tell a big part 
>> of that
>> story.
>>
>> 73, Jim K9YC
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