Tuner ?

[N3WAK]

use a regular center fed dipole, with a balun, and you wont need a tuner

Well, if by "regular center fed dipole, with a balun," you mean a 1/2 wave dipole fed with coax (and a balun), the antenna will only work fine on a single band--on the band where it is resonant.  That is, it will work great on 80 meters, but no place else.  The one exception would be a 40 meter dipole which you could use on 15 meters, where it will be a 3/2 wave dipole. 

As a practical matter, except for the 40/15 meter combination (and, maybe, just maybe, an 80/10 combination), a coax-fed dipole is going to limit you to a single band.  If you want multiband operation, try a coax-fed fan dipole or use ladderline and an external tuner. 

If you Google "$4 Special," you'll find a great introduction on homebrewing a simple, ladder line-fed antenna. 

73, Tony

[AA4PB]

Unfortunately, more than a few people think that you can use a tuner to "force" any antenna to work on any band, regardless of what the antenna was designed for. As a result they wind up with a lot of loss in the tuner and the feed line and a relatively small amount actually being radiated by the antenna.

With the proper antenna, feed line, and tuner a multiband antenna can be efficient.

Don't believe all the advertising hype either. If an antenna is physically small and easy to put up then it very likely compromises efficiency.