. If you have difficulty viewing this video, please enter this title link in your browser: http://youtu.be/3j3BsYbzwvw. Excellent, basic introduction to the design, construction, and use of the Double Extended Zepp Antenna from Stan Gibilisco (W1GV). This antenna delivers approximately 3dB gain over a dipole antenna at the same height above ground. The antenna works best when it is fed with 450 ohm ladder line or 300 ohm TV twinlead. You will need a balanced antenna transmatch (i.e. "tuner") or a tuner/4:1 balun combination to present the proper impedance to your transceiver. According to Stan, the extended double zepp antenna is "a collinear array of two 5/8 waves in phase." You can design the EDZ antenna for any HF amateur radio band you chose. To determine the proper length of the EDZ, you can use the general formula 585/f(MHz). Divide this by 2 to find the length of each element. You can determine the length in meters by dividing your length by 3.28.