helical antenna boom question.

Discussion in 'The Projects Forum' started by Son of a genius, Jan 9, 2011.

  1. Son of a genius

    Thread Starter New Member

    Jan 7, 2011
    I have many 1950 books in my library, including "Radio Eng. Handbook" Terman, the entire McGraw-Hill series of electrical engineering books that i inherited from my dad. I bought several others including the ARRL 2010 antenna and the 2010 handbook. I am highly interested in RF for data transmission and have invested much time reading as much as time permits.

    I want to construct a helical antenna for 1900mhz that can connect to one of my Verizon air cards. I have already removed the internal antenna and examined it. I have built a yagi and a dipole. I am currently using the yagi with the internal air card removed. Works great, but i have no idea if the impedance is matched. I read about the letcher line and am thinking of incorporating it into my feed line somehow, but not till i have a more thorough understanding.
    I read the sections in the Kraus antenna book pertaining to helical antennas, and also the Terman "Radio Eng. Handbook". They were both over my head in their technical explanations. The ARRL books were very clear and informative, more at my level. I believe that I comprehend the basic design variables that determine spacing, diameters, and helical ratio. The one part I can't seem to find is how the boom affects the helix. Some of the examples show channel or square tube, others show no boom at all.

    My question is: how does the boom mount both physically and electronically to the reflector. I am happy to read any book and struggle through the learning curve, but I would like to get started building this thing.

    Thank you
    Todd Daggett
  2. bertus


    Apr 5, 2008
    Son of a genius likes this.
  3. Son of a genius

    Thread Starter New Member

    Jan 7, 2011
    Thank you Sir. That is an excellent website. I was going to go forward with a 1 1/2 ID abs pipe with 14AWG bare wire hot glued at the S .25 ratio intervals, cut a hole in the solid 5" OD flat reflector to allow joining of abs components for structural strength, but now I'm going to study a bit more. Thanks much