up: [[project:hgg:Antenna Design|Project HGG: Antenna Design]]

====== Project: HGG - Antenna Design / J-Pole ======

[[http://shackspace.de/gallery/index.php/Projekte/HGG/jpoledesign|{{http://shackspace.de/gallery/var/thumbs/Projekte/HGG/jpoledesign.png}}]]

  * A = 3/4 λ
  * B = 1/4 λ
  * C = adjust to 50 Ω wave impedance between solder joints
  * D = 4 turn balun to keep coax line from becoming part of the radiator



TODO
  * describe how to fine-tune C

  * HAM Operators use SWR-Meters, these show the overlay-ratio between in- and out-flowing wave.
  * An SWR ratio lower than 1:1.5 is ok. 1:1 is perfect
  * Sadly you need an transmitter to use this methode (you may ask a nearby HAM)
  * SWR-Meters for 2-meter/70-cm band cost about 50€ for a cheap one
  * The Cheap CB SWR-Meters are only useful for 11-Meter band

===== How to tune =====
  * Nibble away bits on both arms while maintaining the (3/4 λ) / (1/4 λ) ratio.