HG>RW>The other issue is that Tom is thinking that a yagi and a LPA are   
   HG>RW>one and the same antenna, when in fact they are two different   
   HG>RW>designs and each is engineered differently.   
      
   HG>Agreed.   
      
   Abbsolutly NOT true. I know a great Deal about antennas them Roy   
   Thinks. What we have is a Termonology gap. Things like calling an   
   "Element" a "Boom" rwally complicats the situation.   
      
   HG>RW>i.e. The LPA antenna normally consists of a series of dipoles   
   HG>RW>(directors, radials) positioned along the antenna axis, which are   
   HG>RW>spaced following a logarithmic function of the frequency.   
      
   HG>Actually there are two different kinds of log periodic directive   
   HG>antennas.   
      
   HG>The LPA antenna you are writing about has several driven elements that   
   HG>are fed by crossing the feed to every element next in line. The lengts   
   HG>of the driven elements are staggered to achieve a broader bandwidth.   
      
   HG>I know this type particularly well because I have built and measured   
   HG>several concepts for both 2 m and 70 cm and used them actively.   
      
   HG>Behind the stack of driven elements there usually is a reflector and in   
   HG>front of the driven elements directors. This antenna is often called a   
   HG>KLM-yagi because the KLM company was the first to manufacture antennas   
   HG>of thes kind originally presented in an article in QST.   
      
   HG>The other kind of LPA is one built on two booms insulated from each   
   HG>other and fed from (often) the front end. The elements are not dipoles   
   HG>per se but are quarter wave length directors staggered on the twin booms   
   HG>so that each director is only half of a director the second half of it   
   HG>being placed where the next director (in a yagi) should have been.   
      
   Exactically and that is a prefect explination aobut the point i was   
   trying to make   
   ---   
    þ SLMR 2.1a þ 0     
    * Origin: Fidonet Since 1991 bbs.docsnetservices.com (1:123/140)