A few years ago, QST described a dipole for 20 through 10 meters that would 
work well in situations where you can get to the antenna in order to add or 
remove wire in order to change bands.

You begin with a 10 meter dipole. Rather than attaching string to the other 
end of the two end insulators, you attach enough wire to make the antenna 
resonant on 12 meters. You keep adding insulators and wire until you reach 
the length of a 20 meter dipole.

You also install short clip leads on each set of wires.

You could also add 6 meters, and or drop 20 meters if you wish.

To change from 10 to 12 meters, you simply clip the 12 meter jumper across 
the insulator onto the end of the 10 meter dipole.

Do the same for 15, 17, or 20 meters. For 20 meters, all insulators prior to 
the 20 meter extension will have jumpers connected across them.

You will have to play with it a bit, but, this arrangement would most likely 
make the use of a tuner unnecessary.

At first glance, it would appear that most apartment balconies won't handle 
a 20 meter dipole. However, a dipole can be bent to some degree without a 
major impact on its effectiveness.

L. B. Cebik describes the bending options on his wonderful antenna info page

http://www.cebik.com

Once there, go to the antennas section, and read "The ZigZag Dipole," "The B 
antenna," and "the L Antenna" links.

Bending the antenna will cause a need for more tuning adjustments, but a 
little patience and a friend with an antenna analyzer will produce good 
results.


Mike Duke, K5XU
American Council of Blind Radio Amateurs