80 meter dipole :

When I was a Novice, that is what I used, a center fed 40 meter dipole,and worked 40 and 15 meters with it. I made a couple of contacts on 80 but stayed mostly on 40. Coax connected directly to antenna at the center insulator. Now days, I am using an 80 meter bent into a U shape and fed off center and I get better results. Not much is needed for it except 135 feet of wire, three insulators (in my case, I only use one insulator and insulated wire and attached to the rain gutters with Christmas decoration clips), and a 4:1 balun.

Here is a website that explains how such a simple antenna works.

http://www.yccc.org/Articles/Antennas/N1IW/OCFD_basic.ppt

Courtesy : Jim (ham-antennas@yahoogroups.com)