As featured in the April 2009 Trail-Friendly Radio column in WorldRadio Online magazine by Richard Fisher, KI6SN, the W3EDP end-fed wire antenna is a great, versatile performer when you're out and about in the field. Spreaders, made of specially cut PVC pipe material, provide lightweight spacing for the antenna and accompanying matching section.
The 84-foot antenna, 17-foot matching section, spreaders and an antenna tuning unit don't add much weight or take up much space in your radio tote bag.
A test set-up in Southern California a few years ago (pictured below) put the W3EDP through its paces on 40- and 20-meter CW during an on-air competition. The antenna is easy to put up and take down, and under field conditions can be used with only one support - a great advantage when you're operating above the tree line.
Here are links to sites with information related to the W3EDP antenna:
THE FFD ANTENNA: A Field-Friendly Doublet, With Notes on Related Designs, by Charles Lofgren, W6JJZ
KB6NU's HAM RADIO BLOG: The W3EDP Antenna, by Dan Romanchik, KB6NU
DXERS UNLIMITED: Item 3 - The W3EDP Antenna, by Arnie Coro, CO2KK
Field-Deployable Antennas, by William Eric McFadden, WD8RIF