Harry K7ZOV left this comment on AmateurRadio.com - thought I would re-post it here (for those of you who might not visit that fine site).
"I was in TX for the holidays. I brought 2 antennas. But used only one with both my TenTec Eagle and my KX3. No counterpoise. No Ground. 20 ft of coax. Worked 80-6 with the KX3 internal ATU. Worked Cuba, South America to Canada. The West coast from the far east side of Texas and lots of States.
Check out the link for more detail. Oh and the “wire” part was only a bit over 50 ft and hanging from a tree at about 30 ft at the highest point and 10 feet at the lowest point. My favorite antenna now.. LINK: http://www.earchi.org/92011endfedfiles/Endfed6_40.pdf
For a 40 meter and 20 meter only… Here is a second link:
Have fun and 73 one and all
Thanks, Harry - great links to EFHW antennas that you can buy or build.
And here's another thought - although I have never used them, I do have friends who have had great success with small magnetic loop antennas. Not only are they great for portable ops (WGØAT uses one) but they are also great for those of you who are antenna restricted. A friend of mine here in NJ thought his Hamming days were over when he moved into an apartment that was constructed from materials that in essence, created a live-in Faraday shield. He started using magnetic loops and was shortly working DX again at QRP power levels from inside the apartment! http://www.alexloop.com/
You might also want to check out the Yo-Yo-tennas that Bill WA8MEA sells - they look pretty good for taking out to the field - http://hamradiofun.com/, if you're not inclined to "roll your own".
72 de Larry W2LJ
QRP - When you care to send the very least!