VHF-UHF Antennas

VHF-UHF Antennas

Verticals

J-Poles

• ARRLWeb: VHF J-Pole Antenna
  http://www.arrl.org/tis/info/JPole-V.html
• The Copper Cactus
  http://archimedes.galilei.com/raiar/cactus.html
• Copper Dual-Band Super J-Pole
  http://www.n7qvc.com/copper.html
• Copper J-Pole 2 Meter Antenna
  http://home.att.net/~dale.keller/ham/antenna/jpole.htm
• Design Your Own J-Pole Antenna
  http://www.packetradio.com/jpol.htm
• J-POLE ANTENNA
  http://www.vk1.wia.ampr.org/bulletins/jpole.html
• TCARS Virtual Elmer - How to Build a 2-Meter J-Pole
  http://www.tcars.org/elmer/jpole.html

J-Pole Choke

It is recommended that a current choke be used with the J-Pole when being fed with coax since it is an unbalanced feed-line. The choke helps keep the transmission line from radiating and altering the radiation pattern of the J-Pole. Most descriptions I have read have suggested four or five turns of coax within a 5 inch diameter loop.

Directional VHF/UHF Antennas

• Quagi Antenna
  http://commfaculty.fullerton.edu/woverbeck/quagi.htm

Resources

• Online helix calculator
  http://vhf.worldsbest.com.au/Helix.htm