RE: ARLA/CLUSTER: Re: [CT-Com. & Tec.] HF multiband beam "MARÍA MALUCA"

[Filipe Ferreira]

Boa tarde colega Já construi e operei uma antena destas com resultados muito razoáveis nos 18 e 14MHz, por vezes bons nos 21, 24 e 28 MHz. Muito simples de construir, tenho um artigo mais detalhado no meu blog:
 http://filipect1ddw.blogspot.pt/ Há várias variações técnicas de construção mas a que mais me convençe é a do colega alemão cujo esquema está no artigo do meu blogue.Boa construção e Boas Festas. CT1DDW - Filipe FerreiraDate: Thu, 20 Dec 2012 12:31:23 +0100
From: ct1ilt  gmail.com
To: ct-comunicacoes-e-tecnologias  googlegroups.com
CC: cluster  radio-amador.net
Subject: ARLA/CLUSTER: Re: [CT-Com. & Tec.] HF multiband beam "MAR�A MALUCA"

Já alguem testou esta antena ?

F. Lopes CT1ILT




2012/12/19 Carlos Fonseca - CT1GFQ <ct1gfqgrupos  gmail.com>





HF multiband beam 
"MAR�A MALUCA"
Published as an article on URE's magazine 
"Radioaficionados" on January 2009
 
    Invented by José 
Salvador Luiz Victor Marinaro (PY2BBP) in 1957, this antenna is more than a 
dipole, it is a dipole with a passive element which works as a director or 
reflector element so there is a directional gain. Works from 20 to 6 meter 
bands. In 12, 10 and 6 meter the passive element works as reflector instead of 
director, then a 180º rotation is needed to work the same 
direction.
 
         
   

    To build the elements can be used 
aluminium pipes of several diameters, linked and fixed by screws, to get the 
needed lengths. The dipole stands its two parts by a pvc pipe and a methacrylate 
plate.
 

                       
                              
   
 
    To feed this antenna a 450Ω 
ladder line is 
needed and antenna tuner too. Also a BALUN is 
needed which can be 1:1 or 4:1. Mine is a 1:1 current BALUN wound on a FT-240-43 
core (12 bifilar turns).
 

                                                                        
   
 
    Ladder line length is important 
because according to the length you cut it and frequency, impedance values can 
be so high than the tuner cannot match. Minimum length is about 13.7 meters. 
Then I added a RG-213 to reach my radio room. This length must be also adjusted 
to be matched by the tuner with SWR 1:1. The following diagram shows the 
instalation.
 

  
    
 
    The ladder line must be insulated 
from metalic objects about 15 to 20 cm. Can be replaced by two parallel 
RG-62 (93Ω) coaxial cables, then feed line will be 186Ω.  

  



  
    
                                             
      
    Map shows contacts I made when 
testing the antenna "Maria Maluca". In black color are 20 meter band QSOs, blue 
are on 17m. and red are on 15m. Mode was BPSK31 in all contacts, power 30-40W. 
The 80% of QSOs reported RST 599.
                                            


  
    
      
 
 
Technical 
data:
Bands:                        
20, 17, 15, 12, 10 y 6 meter
Gain:                         
7.26 - 2.25dBi
Front/Back relation 
(F/B):    6.63 - 0.48dB
Bandwidth @ SWR 
2:1:          20m.: 
135kHz
    17m.: 
>100kHz
    15m.: 
260kHz
    12m.: 
>100kHz
    10m.: 
390kHz
Max 
power:                    
1000W
Boom 
length:                  
1.46 m.
Longest 
element:              
7.56 m.
Turning 
radius:               
3.9 m.
Windload:                     
0.2 m² 
Weight:                       
3.6 kg
 
http://perso.orange.es/isaac.dg/antena%20maria%20maluca.htm

 
73's de 
Carlos CT1GFQ
SKCC#466
REP#1406



-- 

Para mais informações/opções visite o site, e edite a sua conta:

http://groups.google.com/group/ct-comunicacoes-e-tecnologias?hl=en?hl=pt-PT



-- 
Regards,
Filipe Lopes 
CT1ILT aka CR6K




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