ARLA/CLUSTER: As Yagis revolucionarias em fotos.

[Joel Lobão]

Olá Colega Matias,

Este sistema de alimentação também funciona para yaguis de HF acima dos
28mhz?

Joel Lobão - CT1HXB

2009/5/28 antonio matias <ct1ffu  hotmail.com>

> Olá Gomes. A LFA   : loop feed array não é uma moxon, mas  sim um
> loop, rectângulo fechado.
> Este sistema é muito interessante, pois apresenta uma isenção de lóbulos
> laterais quase nula
> o que permite que a antena tenha uma temperatura de ruído
> Kº extremamente baixa.
> Este loop saiu ainda com bonus, pois além das vantagens do
> ruido, melhor sustentabilidade mecânica, permite que seja
> alimentada de duas maneiras.
> Uma a antena fica com o ganho máximo, mas com perda de largura de banda.
> Outra é o oposto, sacrificando um pouco do ganho, a antena permite
> cobertura de mais banda.
> Isto sempre garantindo uma impedância de  50 homs e reactância sempre perto
> de j 0.
> A diferença consiste simplesmente no ponto de alimentação.
> Alimentado como na foto ( elemento perto do reflector), é onde tem mais
> ganho, se alimentar no lado
>  da frente do rectângulo ( elemento perto do 1º director)tem mais largura
> de banda.
>
> em anexo algumas antenas por mim desenhadas no sistema FLA.
> Pode-se ver nas fotos como ligar a alimentação.
> Plot de radiação e diagrama de SWR ao longo da banda.
> Note esta antena é para 144mhz e tem 6 metros de boom.
>
> 73's
>   Matias
>
> ------------------------------
> From: ct1hix  sapo.pt
> To: cluster  radio-amador.net
> Subject: Re: ARLA/CLUSTER: As Yagis revolucionarias em fotos.
> Date: Wed, 27 May 2009 18:43:46 +0100
>
>
> Boas
> Não é uma Moxon com elementos parazitas!!!!
>
>
> 73 Gomes CT1HIX
>
> ----- Original Message -----
> *From:* Gomes <ct1hix  sapo.pt>
> *To:* Resumo Noticioso Electrónico ARLA <cluster  radio-amador.net>
> *Sent:* Wednesday, May 27, 2009 6:12 PM
> *Subject:* Re: ARLA/CLUSTER: As Yagis revolucionarias em fotos.
>
> Boas
> Uma Moxon com elementos parazitas!!!????
> Pelo menos é o que me parece....
>
>
> 73 Gomes CT1HIX
>
> ----- Original Message -----
> *From:* João Gonçalves Costa <joao.a.costa  ctt.pt>
> *To:* 'Resumo Noticioso Electrónico ARLA' <cluster  radio-amador.net>
> *Cc:* 'radioamadores_algarve  yahoogrupos.com.br'
> *Sent:* Wednesday, May 27, 2009 5:15 PM
> *Subject:* ARLA/CLUSTER: As Yagis revolucionarias em fotos.
>
>   Written by G0KSC
>
> <http://www.vinecom.co.uk/>
>
> Vine Antennas are the appointed UK manufaturer and distributor of the LFA
> Yagi
>  KMA Have just been appointed as North American Dealer for LFA Yagis.
> Contact them for more information
> <http://www.kmaantennas.com/>
> Today I am pleased to announce the launch of the new Loop Fed Array (LFA)
> Yagi antenna. The LFA Yagi is not fed with a dipole as would be traditional
> Yagi antennas. Instead it is fed with a full wave loop which is laid flat on
> the boom between the Reflector and first director elements.
> DUBUS Magazine has the exclusive release of the details into this antenna
> with some of the first models although I will be releasing
> build-yourself-models and full information on performance and how it works
> in the very near future.
> In short, the LFA provides superior performance over the traditional Yagi
> in many areas and provides a platform which provides Quad and Yagi features
> in one visually pleasing package.
>
> [image: lfa] A 70MHz LFA Yagi with a massive 10.9dBi Gain
>
> Please bookmark this site and check back over the comming weeks for details
> of how you can build and own one of these exciting antennas!
>
>  Driving was difficult with this one. 2 X 9el LFA for 144MHz portable use
>
> *NO matching device needed, 50 Ohm Direct feed, NO POWER RESTRICTIONS!
> That's the beauty of the LFA!'*
>
>  3 element 28Mhz LFA with an incredible 9dBi Gain!
>
>  The above 3 element 28MHz LFA is now installed at M5ADX. First 'on air'
> tests against a CB 18 foot vertical showed a signal increase from S1 to
> S9!when switching to the G0KSC LFA.
>
>
> Above is the 5 element 50MHz LFA in use now at G0KSC. This antenna is 4.7
> metres long, has just over 11dBi forward gain and 22dB front to back ratio
> at worst. More importantly, the antenna shows a 1:1 flat SWR curve from 50
> to 50.50MHz and a return loss no lower that -30dB down, peaking at -60dB
> down!
>
>
>  a wide-spaced 5 el Yagi for 70MHz ready for the G0KSC Tower. This
> produces 11.3dBi and 25dB F/R
>
> With all LFA's *fine* tuning is made easy by the end pieces of the loop
> being made out of a smaller gauge tubing and hence, a trombone effect allows
> the loop to be increased or decreased in size.
>
>
>
> *Tired of all that noise you pick up from around your own home and other
> building near where you live?*
> This is the first of my new Low-Noise LFA Yagis. Massive suppression side
> lobes in both the H and V plane means minium local noise pick up and minimum
> interferance when transmitting. Details on this antenna and others like it
> will be in the next issue of DUBUS Magazine. The above antenna is a 5
> element LFA for 50MHz with a 6.6 metre boom made from 1.5 inch box section
> tube. Elements are 16mm thick while the loop is 22.23mm thick with 19.05mm
> end sections. *11.5dB Gain, 28dB Front to REAR*. The suppresion extends
> forwards by 15 degress in order to remove straight up and straight down
> lobes.
> *If you are not into building Antennas..*
> *www.vinecom.co.uk *- Vine Antennas are going into production with the LFA
> so check their site out and give them a call with what you are looking for!
>
> *Best DX,*
> *Justin G0KSC *
>
> ------------------------------
>
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