Once upon a time, all amateur bands were harmonically related....for a reason. Not only could you build simpler transmitters, using frequency multipliers for the higher bands....but most fundamental antennas work on harmonic frequencies. Since the WARC bands, which are not harmonically related, came into existence, this is no longer the case. Unlike in days of yore, when an end fed dipole could be operated on every ham band (though presenting a very high resistive component on each one), there is no simple antenna that will work on both "standard" harmonic bands and WARC bands....at least without an antenna tuner. By the way, the end fed dipole, using a broadband transformer, of which a number of commercial units are available, does NOT work well when there's a lot of reactance. It CAN work admirably on a number of harmonic bands, however. Like any other good antenna or accessory, success depends on using it in its original intent. (One reason the G5RV seems to fairly universally suck as an all-band antenna is that it was originally designed as a 20 meter antenna, on which it performs in sterling fashion. It was NEVER intended as an all band antenna). It must also be re-emphasized that resonating and impedance matching are two very different functions, and need to be separated in one's thinking. As a general rule, if you start with a perfectly matched antenna, and then move off of its design frequency, the REACTANCE changes much more rapidly than the radiation resistance. This is why, if you're building a multiband antenna....like a trap dipole or trap vertical...it's much more important to worry about tuning and resonating at your desired operating frequencies than it is to worry about a perfect resistive match. A few moments' fiddling with a Smith chart will verify this.....especially when dealing with a high-impedance feedpoint such as in an end-fed dipole. The reactance oscillates very quickly between nearly infinite capacitance to nearly infinite inductance with a very minuscule frequency change...while the resistance remains fairly consistently high. Stay tuned.