1. If the ad says the antenna will do everything this side of cleaning
up your ham shack, run the other way.
2. If the ad says the antenna will do everything including cleaning up
your ham shack, lock all the doors, and take cover immediately.
3. If an antenna claims to cover every band from DC to Daylight, ask
the manufacturer to explain the difference between their product and a
dummy load. But don't hold your breath while waiting for the answer.
4. Remember that useful fact that was once taught in high school
economics classes: "If it sounds too good to be true, let the buyer
beware."
Mike Duke, K5XU