Because most MARS operation takes place at a state (local) level beams and other antennas, such as verticals, can actually perform worse than a simple dipole or G5RV mounted relatively close to the ground. The reason being is that beams and verticals tend to have lower angles of radiation which, for DX, is great, but will skip over local stations. A dipole or G5RV up about 30 feet (or even less) will provide a vertical radiation pattern and will work well with local contacts, local being defined out to 200-300 miles. During an Army MARS special event activity in Akron Ohio last June, we had two G5RV's, one up about 8 ft and one up about 20 ft and both did very well at contacting all Ohio stations in addition to contacting stations as far away as Florida. Hope that helps.