20 m long wire antenna

TX Four Square Antenna - A 220-ft tower that has five catenary lines, each about 500 feet long. Four of these lines, running NE, SE, SW, and NW support four 1/4-wavelength wire verticals used in a 160-meter four-square antenna.

W5GI Mystery Antenna  ^pop - W5GI Mystery Antenna is a multi-band wire antenna that performs exceptionally well even though it confounds antenna modeling software. This antenna covers 80 to 6 meters with low feed point impedance and will work with most radios, with or without an antenna tuner. It is approximately 100 feet long, can handle the legal limit, and is easy and inexpensive to build. It�s similar to a G5RV but a much better performer especially on 20 meters.

M1IOS - Wonder Whip antenna and tuner Priority listing - M1IOS Wonder Whip antenna - The M1IOS Wonder Whip A 10 dollars QRP Portable Multiband Antenna for HF, VHF and UHF A variation on the Miracle Whip and Wander Wand. This antenna tuning unit will get your SWR really low on telescopic whips, mobile 3/8th antenna and long wires. A remarkable little tuner that really works!

QRP Antenna 80-40-20-15 End Fed Antenna - A long wire antenna that will load up on 80, 40, 20 & 15 meters without an antenna tuner and without balun coils

W3EDP Antenna Checkout for PLP - The W3EDP is a 85 foot long wire and a 17 foot counterpoise. At N4KGL

CantennaCalc - Kioan's calculator for building a Cantenna , directional waveguide antenna for long-range Wi-Fi

Long wire and Un-Un - Testing log wire antennas and a unun by G0KYA