Antenna: 80 meters, Range: 3.5 to 4 MHz
Good 80 meters antennas are easy to build with nothing more than readily available materials. Since 80 meters covers the frequency range of 3.5 to 4 MHz you can use a few algebraic formulas to compute antenna sizes.
80 meters antennas are a great deal like those for 75 meters but there is a problem in the bandwidth of 80 meters antennas. The problem is the bandwidth which is the frequency at the upper and lower edge of the antennas before excessive SWR comes into play. Like 75 meters, 80 meters is a good band for survivalists to consider.
This formula: 234/f can be explained by dividing 234 by the desired frequency in megahertz which will give you the length, in feet, of a 1/4 wave antenna. This formula isn't exact in that it assumes the radiating element is infinitely small. What this means is if the radiating element was one inch in diameter then the resonant length of the antenna would be a little shorter than the calculated one given by the formula gives you.
Using the formula above you will soon see that an antenna for 80 meters is approximately 65 feet 4 and 3/8 inches in length. This antenna measurement can be used for either a vertical antenna for 80 meters or a horizontal antenna for 80 meters.
All though 80 meters is a good band for regional communications you will find mostly Morse code and digital communications in place. 80 meters includes the 75 meter band where voice operation is permitted.