[amsat-bb] Yagi Stacking,

[Mike Thompson]

I replied to this earlier, but I thought it would be worth sending to the
whole board.
The idea is to get each antenna out of the aperture of a smaller antenna as
much as possible.

Hope this helps.

http://www.ifwtech.co.uk/g3sek/stacking/stacking2.htm

On Tue, Feb 21, 2017 at 1:01 PM, Dave Mann <cwo4mann at comcast.net> wrote:

> Same Question here, RE placing the two 2-M Yagis directly next to each
> other and 90 degree angles.
>
> I read where I can put both of my Cushcraft 3-element Yagis together,
> spacing the elements on one so that they are ahead or behind the other set
> of elements.  Then binding the two Yagi booms together.  Feed line would be
> one 1/4 wave and one 1/2 wave, "I think".  Then the two feed lines would be
> soldered together and attached to a PL-259.
>
> I put a couple of photos of my construction project on the AMSAT Facebook
> page, but it only shows the 70cm Cushcraft Circularly Polarized Yagi at one
> end of the cross-boom and a single 3-element Cushcraft Yagi at the other
> end of the cross-member.
>
> I originally placed the second 2-m Yagi at a 1/4 wavelength away from the
> end Yagis, but saw some pretty high SWR readings on both the 70cm and on
> both 2-m Yagis.
>
> This is more difficult to explain in writing than to actually do.  I will
> get some photos up to my Ham Radio DropBox account and post the link here,
> "real soon now".  Photos here might be more illustrative than my written
> explanation (pun intended).
>
> I appreciate all of the comments and other advice received here and on the
> Facebook AMSAT page.
>
> -------------------------
>
> Esto es para mis amigos de habla hispana:
>
> La misma pregunta aquí, RE colocando los dos Yagis 2-M directamente al
> lado del otro y ángulos de 90 grados.
>
> Leí donde puedo poner ambos de mis Cushcraft de 3 elementos Yagis juntos,
> espaciando los elementos en uno para que estén por delante o detrás del
> otro conjunto de elementos. Luego se unen las dos barras de Yagi. La línea
> de alimentación sería una onda 1/4 y una onda 1/2, "creo". A continuación,
> las dos líneas de alimentación se soldarían juntas y se unirían a un PL-259.
>
> Puse un par de fotos de mi proyecto de construcción en la página de
> Facebook de AMSAT, pero sólo muestra los 70cm Cushcraft circularmente
> polarizado Yagi en un extremo de la cruz-boom y un solo 3-elemento
> Cushcraft Yagi en el otro extremo de la cruz- miembro.
>
> En un principio colocé el segundo 2-m Yagi a una longitud de onda 1/4
> lejos del extremo Yagis, pero vi algunas lecturas bastante altas de SWR en
> ambos los 70cm y en ambos 2-m Yagis.
>
> Esto es más difícil de explicar por escrito que hacerlo. Voy a obtener
> algunas fotos hasta mi Ham Radio DropBox cuenta y publicar el enlace aquí,
> "muy pronto". Las fotos aquí pueden ser más ilustrativas que mi explicación
> escrita (juego de palabras).
>
> Agradezco todos los comentarios y otros consejos recibidos aquí y en la
> página de Facebook AMSAT.
>
> 73's
>
> Dave
> N4CVX
>
>
>
>
> On 02/21/2017 10:23 AM, Joe wrote:
>
>>
>> OK using this image as a reference,
>>
>> http://i67.tinypic.com/28mpzkh.jpg
>>
>> Ok the yagis are 8 elements on 2 meters and 21 elements on 70 cm.
>> Similar boom lengths.
>>
>> Now when vertically polarized and stacked side by side as in the top
>> picture how close can they get to each other before starting to mess
>> with each other.
>>
>> Same thing in next image but horizontally polarized so above and below
>> each other.
>>
>> Now if they are 90 deg in rotation IE: one is vertically polarized and
>> the other horizontal, I'm thinking they could even be on the same boom
>> correct?
>>
>> So that brings in the third drawing same antennas but at 45 deg to the
>> horizon but 90 to each other, How close can they get without bugging the
>> other?
>>
>> Now with the 45 deg angle thing,  how much will a metal cross boom mess
>> with them?
>>
>> Joe WB9SBD
>>
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