Check these out. For 20m, this meets the "small and cheap" requirement, has gain over a dipole, and doesn't require radials or a "high" support and is close to invisible. You can substitute small dia aluminum tubing for the vertical wires. http://www.cebik.com/scv/bct.html or for 40m. http://www.cebik.com/scv/bc40ab.html de Doug KR2Q